Merge pull request #3785 from github/mbg/dep/update-undici

Bump `undici` to at least `6.24.0`

.github/codeql/codeql-config-javascript.yml

@@ -1,5 +1,5 @@
 name: "CodeQL config"
-queries: 
+queries:
   - name: Run custom queries
     uses: ./queries
   # Run all extra query suites, both because we want to
@@ -13,3 +13,5 @@ queries:
 paths-ignore:
   - lib
   - tests
+  - "**/*.test.ts"
+  - "**/testing-util.ts"

.github/workflows/pr-checks.yml

@@ -52,14 +52,6 @@ jobs:
       - name: Verify compiled JS up to date
         run: .github/workflows/script/check-js.sh
 
-      - name: Upload esbuild metadata
-        uses: actions/upload-artifact@v7
-        with:
-          name: bundle-metadata-${{ matrix.os }}-${{ matrix.node-version }}
-          path: build-metadata.json
-          retention-days: ${{ (github.ref_name == github.event.repository.default_branch && 90) || 7 }}
-          if-no-files-found: error
-
       - name: Run unit tests
         if: always()
         run: npm test

.gitignore

@@ -12,4 +12,4 @@ eslint.sarif
 # for local incremental compilation
 tsconfig.tsbuildinfo
 # esbuild metadata file
-build-metadata.json
+meta.json

CHANGELOG.md

@@ -4,8 +4,15 @@ See the [releases page](https://github.com/github/codeql-action/releases) for th
 
 ## [UNRELEASED]
 
-- Fixed a bug where two diagnostics produced within the same millisecond could overwrite each other on disk, causing one of them to be lost. [#3852](https://github.com/github/codeql-action/pull/3852)
+No user facing changes.
+
+## 4.35.3 - 01 May 2026
+
 - _Upcoming breaking change_: Add a deprecation warning for customers using CodeQL version 2.19.3 and earlier. These versions of CodeQL were discontinued on 9 April 2026 alongside GitHub Enterprise Server 3.15, and will be unsupported by the next minor release of the CodeQL Action. [#3837](https://github.com/github/codeql-action/pull/3837)
+- Configurations for private registries that use Cloudsmith or GCP OIDC are now accepted. [#3850](https://github.com/github/codeql-action/pull/3850)
+- Best-effort connection tests for private registries now use `GET` requests instead of `HEAD` for better compatibility with various registry implementations. For NuGet feeds, the test is now always performed against the service index. [#3853](https://github.com/github/codeql-action/pull/3853)
+- Fixed a bug where two diagnostics produced within the same millisecond could overwrite each other on disk, causing one of them to be lost. [#3852](https://github.com/github/codeql-action/pull/3852)
+- Update default CodeQL bundle version to [2.25.3](https://github.com/github/codeql-action/releases/tag/codeql-bundle-v2.25.3). [#3865](https://github.com/github/codeql-action/pull/3865)
 
 ## 4.35.2 - 15 Apr 2026
 

build.mjs

@@ -82,6 +82,6 @@ const context = await esbuild.context({
 });
 
 const result = await context.rebuild();
-await writeFile(join(__dirname, "build-metadata.json"), JSON.stringify(result.metafile));
+await writeFile(join(__dirname, "meta.json"), JSON.stringify(result.metafile));
 
 await context.dispose();

lib/defaults.json

@@ -1,6 +1,6 @@
 {
-  "bundleVersion": "codeql-bundle-v2.25.2",
-  "cliVersion": "2.25.2",
-  "priorBundleVersion": "codeql-bundle-v2.25.1",
-  "priorCliVersion": "2.25.1"
+  "bundleVersion": "codeql-bundle-v2.25.3",
+  "cliVersion": "2.25.3",
+  "priorBundleVersion": "codeql-bundle-v2.25.2",
+  "priorCliVersion": "2.25.2"
 }

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "codeql",
-  "version": "4.35.3",
+  "version": "4.35.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "codeql",
-      "version": "4.35.3",
+      "version": "4.35.4",
       "license": "MIT",
       "workspaces": [
         "pr-checks"
@@ -410,15 +410,6 @@
         "undici": "^6.23.0"
       }
     },
-    "node_modules/@actions/github/node_modules/undici": {
-      "version": "6.23.0",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-6.23.0.tgz",
-      "integrity": "sha512-VfQPToRA5FZs/qJxLIinmU59u0r7LXqoJkCzinq3ckNJp3vKEh7jTWN589YQ5+aoAC/TGRLyJLCPKcLQbM8r9g==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=18.17"
-      }
-    },
     "node_modules/@actions/glob": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/@actions/glob/-/glob-0.5.1.tgz",
@@ -439,15 +430,6 @@
         "undici": "^6.23.0"
       }
     },
-    "node_modules/@actions/http-client/node_modules/undici": {
-      "version": "6.23.0",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-6.23.0.tgz",
-      "integrity": "sha512-VfQPToRA5FZs/qJxLIinmU59u0r7LXqoJkCzinq3ckNJp3vKEh7jTWN589YQ5+aoAC/TGRLyJLCPKcLQbM8r9g==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=18.17"
-      }
-    },
     "node_modules/@actions/io": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/@actions/io/-/io-2.0.0.tgz",
@@ -1494,14 +1476,6 @@
         "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
       }
     },
-    "node_modules/@fastify/busboy": {
-      "version": "2.1.1",
-      "resolved": "https://registry.npmjs.org/@fastify/busboy/-/busboy-2.1.1.tgz",
-      "integrity": "sha512-vBZP4NlzfOlerQTnba4aqZoMhE/a9HY7HRqoOPaETQcSQuWEIyZMHGfVu6w9wGtGK5fED5qRs2DteVCjOH60sA==",
-      "engines": {
-        "node": ">=14"
-      }
-    },
     "node_modules/@github/browserslist-config": {
       "version": "1.0.0",
       "dev": true,
@@ -9854,14 +9828,12 @@
       }
     },
     "node_modules/undici": {
-      "version": "5.29.0",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-5.29.0.tgz",
-      "integrity": "sha512-raqeBD6NQK4SkWhQzeYKd1KmIG6dllBOTt55Rmkt4HtI9mwdWtJljnrXjAFUBLTSN67HWrOIZ3EPF4kjUw80Bg==",
-      "dependencies": {
-        "@fastify/busboy": "^2.0.0"
-      },
+      "version": "6.24.1",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-6.24.1.tgz",
+      "integrity": "sha512-sC+b0tB1whOCzbtlx20fx3WgCXwkW627p4EA9uM+/tNNPkSS+eSEld6pAs9nDv7WbY1UUljBMYPtu9BCOrCWKA==",
+      "license": "MIT",
       "engines": {
-        "node": ">=14.0"
+        "node": ">=18.17"
       }
     },
     "node_modules/undici-types": {

package.json

@@ -1,11 +1,11 @@
 {
   "name": "codeql",
-  "version": "4.35.3",
+  "version": "4.35.4",
   "private": true,
   "description": "CodeQL action",
   "scripts": {
     "_build_comment": "echo 'Run the full build so we typecheck the project and can reuse the transpiled files in npm test'",
-    "build": "./scripts/check-node-modules.sh && npm run transpile && node build.mjs",
+    "build": "./scripts/check-node-modules.sh && npm run transpile && node build.mjs && npx tsx ./pr-checks/bundle-metadata.ts",
     "lint": "eslint --report-unused-disable-directives --max-warnings=0 .",
     "lint-ci": "SARIF_ESLINT_IGNORE_SUPPRESSED=true eslint --report-unused-disable-directives --max-warnings=0 . --format @microsoft/eslint-formatter-sarif --output-file=eslint.sarif",
     "lint-fix": "eslint --report-unused-disable-directives --max-warnings=0 . --fix",
@@ -90,6 +90,7 @@
       "semver": ">=6.3.1"
     },
     "brace-expansion@2.0.1": "2.0.2",
-    "glob": "^11.1.0"
+    "glob": "^11.1.0",
+    "undici": "^6.24.0"
   }
 }

pr-checks/api-client.ts

@@ -1,16 +1,8 @@
-import { ParseArgsConfig } from "node:util";
-
 import * as githubUtils from "@actions/github/lib/utils";
 import { type Octokit } from "@octokit/core";
 import { type PaginateInterface } from "@octokit/plugin-paginate-rest";
 import { type Api } from "@octokit/plugin-rest-endpoint-methods";
 
-/** Identifies the CodeQL Action repository. */
-export const CODEQL_ACTION_REPO = {
-  owner: "github",
-  repo: "codeql-action",
-};
-
 /** The type of the Octokit client. */
 export type ApiClient = Octokit & Api & { paginate: PaginateInterface };
 
@@ -19,16 +11,3 @@ export function getApiClient(token: string): ApiClient {
   const opts = githubUtils.getOctokitOptions(token);
   return new githubUtils.GitHub(opts);
 }
-
-export interface TokenOption {
-  /** The token to use to authenticate to the GitHub API. */
-  token?: string;
-}
-
-/** Command-line argument parser settings for the token parameter. */
-export const TOKEN_OPTION_CONFIG = {
-  // The token to use to authenticate to the API.
-  token: {
-    type: "string",
-  },
-} satisfies ParseArgsConfig["options"];

pr-checks/bundle-metadata.ts

@@ -1,43 +1,8 @@
 #!/usr/bin/env npx tsx
 
 import * as fs from "node:fs/promises";
-import { parseArgs, ParseArgsConfig } from "node:util";
 
-import * as exec from "@actions/exec";
-
-import {
-  ApiClient,
-  CODEQL_ACTION_REPO,
-  getApiClient,
-  TOKEN_OPTION_CONFIG,
-} from "./api-client";
-import { BASELINE_BUNDLE_METADATA_FILE, BUNDLE_METADATA_FILE } from "./config";
-
-const optionsConfig = {
-  ...TOKEN_OPTION_CONFIG,
-  branch: {
-    type: "string",
-    default: "main",
-  },
-  runner: {
-    type: "string",
-    default: "macos-latest",
-  },
-  "node-version": {
-    type: "string",
-    default: "24",
-  },
-} satisfies ParseArgsConfig["options"];
-
-function parseOptions() {
-  const { values: options } = parseArgs({
-    options: optionsConfig,
-  });
-
-  return options;
-}
-
-type Options = ReturnType<typeof parseOptions>;
+import { BUNDLE_METADATA_FILE } from "./config";
 
 interface InputInfo {
   bytesInOutput: number;
@@ -58,125 +23,21 @@ function toMB(bytes: number): string {
   return `${(bytes / (1024 * 1024)).toFixed(2)}MB`;
 }
 
-async function getBaselineFrom(client: ApiClient, options: Options) {
-  const workflowRun = await client.rest.actions.listWorkflowRuns({
-    ...CODEQL_ACTION_REPO,
-    branch: options.branch,
-    workflow_id: "pr-checks.yml",
-    status: "success",
-    per_page: 1,
-    event: "push",
-  });
-
-  if (workflowRun.data.total_count === 0) {
-    throw new Error(
-      `Expected to find a 'pr-checks.yml' run for '${options.branch}', but found none.`,
-    );
-  }
-
-  const expectedArtifactName = `bundle-metadata-${options.runner}-${options["node-version"]}`;
-  const artifacts = await client.rest.actions.listWorkflowRunArtifacts({
-    ...CODEQL_ACTION_REPO,
-    run_id: workflowRun.data.workflow_runs[0].id,
-    name: expectedArtifactName,
-  });
-
-  if (artifacts.data.total_count === 0) {
-    throw new Error(
-      `Expected to find an artifact named '${expectedArtifactName}', but found none.`,
-    );
-  }
-
-  const downloadInfo = await client.rest.actions.downloadArtifact({
-    ...CODEQL_ACTION_REPO,
-    artifact_id: artifacts.data.artifacts[0].id,
-    archive_format: "zip",
-  });
-
-  // This works fine for us with our version of Octokit, so we don't need to
-  // worry about over-complicating this script and handle other possibilities.
-  if (downloadInfo.data instanceof ArrayBuffer) {
-    const archivePath = `${expectedArtifactName}.zip`;
-    await fs.writeFile(archivePath, Buffer.from(downloadInfo.data));
-
-    console.info(`Extracting zip file: ${archivePath}`);
-    await exec.exec("unzip", ["-o", archivePath, "-d", "."]);
-
-    // We no longer need the archive after unzipping it.
-    await fs.rm(archivePath);
-
-    // Check that we have the expected file.
-    try {
-      await fs.stat(BASELINE_BUNDLE_METADATA_FILE);
-    } catch (err) {
-      throw new Error(
-        `Expected '${BASELINE_BUNDLE_METADATA_FILE}' to have been extracted, but it does not exist: ${err}`,
-      );
-    }
-
-    const baselineData = await fs.readFile(BASELINE_BUNDLE_METADATA_FILE);
-    return JSON.parse(String(baselineData)) as Metadata;
-  } else {
-    throw new Error("Expected to receive artifact data, but didn't.");
-  }
-}
-
 async function main() {
-  const options = parseOptions();
-
-  if (options.token === undefined) {
-    throw new Error("Missing --token");
-  }
-
-  // Initialise the API client.
-  const client = getApiClient(options.token);
-  const baselineMetadata = await getBaselineFrom(client, options);
-
   const fileContents = await fs.readFile(BUNDLE_METADATA_FILE);
   const metadata = JSON.parse(String(fileContents)) as Metadata;
 
-  console.info("Comparing bundle metadata to baseline...");
-
-  const filesInBaseline = new Set(Object.keys(baselineMetadata.outputs));
-  const filesInCurrent = new Set(Object.keys(metadata.outputs));
-
-  const filesNotPresent = filesInBaseline.difference(filesInCurrent);
-  if (filesNotPresent.size > 0) {
-    console.info(`Found ${filesNotPresent.size} file(s) which were removed:`);
-    for (const removedFile of filesNotPresent) {
-      console.info(`  - ${removedFile}`);
-    }
-  }
-
   for (const [outputFile, outputData] of Object.entries(
     metadata.outputs,
   ).reverse()) {
-    const baselineOutputData = baselineMetadata.outputs[outputFile];
+    console.info(`${outputFile}: ${toMB(outputData.bytes)}`);
 
-    if (baselineOutputData === undefined) {
-      console.info(`${outputFile}: New file (${toMB(outputData.bytes)})`);
-    } else {
-      const percentageDifference =
-        ((outputData.bytes - baselineOutputData.bytes) /
-          baselineOutputData.bytes) *
-        100.0;
+    for (const [inputName, inputData] of Object.entries(outputData.inputs)) {
+      // Ignore any inputs that make up less than 5% of the output.
+      const percentage = (inputData.bytesInOutput / outputData.bytes) * 100.0;
+      if (percentage < 5.0) continue;
 
-      if (Math.abs(percentageDifference) >= 5) {
-        console.info(
-          `${outputFile}: ${toMB(outputData.bytes)} (${percentageDifference.toFixed(2)}%)`,
-        );
-
-        for (const [inputName, inputData] of Object.entries(
-          outputData.inputs,
-        )) {
-          // Ignore any inputs that make up less than 5% of the output.
-          const percentage =
-            (inputData.bytesInOutput / outputData.bytes) * 100.0;
-          if (percentage < 5.0) continue;
-
-          console.info(`  ${inputName}: ${toMB(inputData.bytesInOutput)}`);
-        }
-      }
+      console.info(`  ${inputName}: ${toMB(inputData.bytesInOutput)}`);
     }
   }
 }

pr-checks/config.ts

@@ -10,17 +10,7 @@ export const PR_CHECKS_DIR = __dirname;
 export const PR_CHECK_EXCLUDED_FILE = path.join(PR_CHECKS_DIR, "excluded.yml");
 
 /** The path to the esbuild metadata file. */
-export const BUNDLE_METADATA_FILE = path.join(
-  PR_CHECKS_DIR,
-  "..",
-  "build-metadata.json",
-);
-
-/** The path of the baseline esbuild metadata file, once extracted from a workflow artifact. */
-export const BASELINE_BUNDLE_METADATA_FILE = path.join(
-  PR_CHECKS_DIR,
-  "build-metadata.json",
-);
+export const BUNDLE_METADATA_FILE = path.join(PR_CHECKS_DIR, "..", "meta.json");
 
 /** The `src` directory. */
 const SOURCE_ROOT = path.join(PR_CHECKS_DIR, "..", "src");

pr-checks/sync-checks.ts

@@ -7,20 +7,16 @@ import { parseArgs } from "node:util";
 
 import * as yaml from "yaml";
 
-import {
-  type ApiClient,
-  CODEQL_ACTION_REPO,
-  getApiClient,
-  TOKEN_OPTION_CONFIG,
-  TokenOption,
-} from "./api-client";
+import { type ApiClient, getApiClient } from "./api-client";
 import {
   OLDEST_SUPPORTED_MAJOR_VERSION,
   PR_CHECK_EXCLUDED_FILE,
 } from "./config";
 
 /** Represents the command-line options. */
-export interface Options extends TokenOption {
+export interface Options {
+  /** The token to use to authenticate to the GitHub API. */
+  token?: string;
   /** The git ref to use the checks for. */
   ref?: string;
   /** Whether to actually apply the changes or not. */
@@ -29,6 +25,12 @@ export interface Options extends TokenOption {
   verbose: boolean;
 }
 
+/** Identifies the CodeQL Action repository. */
+const codeqlActionRepo = {
+  owner: "github",
+  repo: "codeql-action",
+};
+
 /** Represents a configuration of which checks should not be set up as required checks. */
 export interface Exclusions {
   /** A list of strings that, if contained in a check name, are excluded. */
@@ -98,7 +100,7 @@ async function getChecksFor(
   const response = await client.paginate(
     "GET /repos/{owner}/{repo}/commits/{ref}/check-runs",
     {
-      ...CODEQL_ACTION_REPO,
+      ...codeqlActionRepo,
       ref,
     },
   );
@@ -131,7 +133,7 @@ async function getChecksFor(
 /** Gets the current list of release branches. */
 async function getReleaseBranches(client: ApiClient): Promise<string[]> {
   const refs = await client.rest.git.listMatchingRefs({
-    ...CODEQL_ACTION_REPO,
+    ...codeqlActionRepo,
     ref: "heads/releases/v",
   });
   return refs.data.map((ref) => ref.ref).sort();
@@ -144,7 +146,7 @@ async function patchBranchProtectionRule(
   checks: Set<string>,
 ) {
   await client.rest.repos.setStatusCheckContexts({
-    ...CODEQL_ACTION_REPO,
+    ...codeqlActionRepo,
     branch,
     contexts: Array.from(checks),
   });
@@ -161,7 +163,7 @@ async function updateBranch(
 
   // Query the current set of required checks for this branch.
   const currentContexts = await client.rest.repos.getAllStatusCheckContexts({
-    ...CODEQL_ACTION_REPO,
+    ...codeqlActionRepo,
     branch,
   });
 
@@ -203,7 +205,10 @@ async function updateBranch(
 async function main(): Promise<void> {
   const { values: options } = parseArgs({
     options: {
-      ...TOKEN_OPTION_CONFIG,
+      // The token to use to authenticate to the API.
+      token: {
+        type: "string",
+      },
       // The git ref for which to retrieve the check runs.
       ref: {
         type: "string",

src/api-client.ts

@@ -128,6 +128,8 @@ export async function getGitHubVersionFromApi(
 
   // Doesn't strictly have to be the meta endpoint as we're only
   // using the response headers which are available on every request.
+  //
+  // See https://docs.github.com/en/rest/meta/meta#get-github-meta-information.
   // eslint-disable-next-line @typescript-eslint/no-unsafe-call
   const response = await apiClient.rest.meta.get();
 
@@ -164,6 +166,9 @@ export async function getGitHubVersion(): Promise<GitHubVersion> {
 
 /**
  * Get the path of the currently executing workflow relative to the repository root.
+ *
+ * See https://docs.github.com/en/rest/actions/workflow-runs#get-a-workflow-run
+ * and https://docs.github.com/en/rest/actions/workflows#get-a-workflow.
  */
 export async function getWorkflowRelativePath(): Promise<string> {
   const repo_nwo = getRepositoryNwo();
@@ -252,9 +257,13 @@ export interface ActionsCacheItem {
   size_in_bytes?: number;
 }
 
-/** List all Actions cache entries matching the provided key and ref. */
+/**
+ * List all Actions cache entries starting with the provided key prefix and matching the provided ref.
+ *
+ * See https://docs.github.com/en/rest/actions/cache#list-github-actions-caches-for-a-repository.
+ */
 export async function listActionsCaches(
-  key: string,
+  keyPrefix: string,
   ref?: string,
 ): Promise<ActionsCacheItem[]> {
   const repositoryNwo = getRepositoryNwo();
@@ -264,13 +273,17 @@ export async function listActionsCaches(
     {
       owner: repositoryNwo.owner,
       repo: repositoryNwo.repo,
-      key,
+      key: keyPrefix,
       ref,
     },
   );
 }
 
-/** Delete an Actions cache item by its ID. */
+/**
+ * Delete an Actions cache item by its ID.
+ *
+ * See https://docs.github.com/en/rest/actions/cache#delete-a-github-actions-cache-for-a-repository-using-a-cache-id.
+ */
 export async function deleteActionsCache(id: number) {
   const repositoryNwo = getRepositoryNwo();
 
@@ -281,7 +294,11 @@ export async function deleteActionsCache(id: number) {
   });
 }
 
-/** Retrieve all custom repository properties. */
+/**
+ * Retrieve all custom repository properties.
+ *
+ * See https://docs.github.com/en/rest/repos/custom-properties#get-all-custom-property-values-for-a-repository.
+ */
 export async function getRepositoryProperties(repositoryNwo: RepositoryNwo) {
   return getApiClient().request("GET /repos/:owner/:repo/properties/values", {
     owner: repositoryNwo.owner,

src/defaults.json

@@ -1,6 +1,6 @@
 {
-  "bundleVersion": "codeql-bundle-v2.25.2",
-  "cliVersion": "2.25.2",
-  "priorBundleVersion": "codeql-bundle-v2.25.1",
-  "priorCliVersion": "2.25.1"
+  "bundleVersion": "codeql-bundle-v2.25.3",
+  "cliVersion": "2.25.3",
+  "priorBundleVersion": "codeql-bundle-v2.25.2",
+  "priorCliVersion": "2.25.2"
 }

src/json/index.test.ts

@@ -0,0 +1,46 @@
+import test from "ava";
+
+import { setupTests } from "../testing-utils";
+
+import * as json from ".";
+
+setupTests(test);
+
+const testSchema = {
+  requiredKey: json.string,
+};
+
+const optionalSchema = {
+  optionalKey: json.optional(json.string),
+};
+
+test("validateSchema - required properties are required", async (t) => {
+  t.false(json.validateSchema(testSchema, {}));
+  t.false(json.validateSchema(testSchema, { requiredKey: undefined }));
+  t.false(json.validateSchema(testSchema, { requiredKey: null }));
+  t.false(json.validateSchema(testSchema, { requiredKey: 0 }));
+  t.false(json.validateSchema(testSchema, { requiredKey: 123 }));
+  t.false(json.validateSchema(testSchema, { requiredKey: false }));
+  t.false(json.validateSchema(testSchema, { requiredKey: true }));
+  t.false(json.validateSchema(testSchema, { requiredKey: [] }));
+  t.false(json.validateSchema(testSchema, { requiredKey: {} }));
+  t.true(json.validateSchema(testSchema, { requiredKey: "" }));
+  t.true(json.validateSchema(testSchema, { requiredKey: "foo" }));
+});
+
+test("validateSchema - optional properties are optional", async (t) => {
+  // Optional fields may be absent
+  t.true(json.validateSchema(optionalSchema, {}));
+  t.true(json.validateSchema(optionalSchema, { optionalKey: undefined }));
+  t.true(json.validateSchema(optionalSchema, { optionalKey: null }));
+
+  // But, if present, should have the expected type
+  t.false(json.validateSchema(optionalSchema, { optionalKey: 0 }));
+  t.false(json.validateSchema(optionalSchema, { optionalKey: 123 }));
+  t.false(json.validateSchema(optionalSchema, { optionalKey: false }));
+  t.false(json.validateSchema(optionalSchema, { optionalKey: true }));
+  t.false(json.validateSchema(optionalSchema, { optionalKey: [] }));
+  t.false(json.validateSchema(optionalSchema, { optionalKey: {} }));
+  t.true(json.validateSchema(optionalSchema, { optionalKey: "" }));
+  t.true(json.validateSchema(optionalSchema, { optionalKey: "foo" }));
+});

src/json/index.ts

@@ -36,3 +36,82 @@ export function isStringOrUndefined(
 ): value is string | undefined {
   return value === undefined || isString(value);
 }
+
+/**
+ * Represents a field of type `T` in a schema.
+ * Carries a validation function and flag indicating whether the field is required or not.
+ */
+export type Validator<T> = {
+  validate: (val: unknown) => val is T;
+  required: boolean;
+};
+
+/** Extracts `T` from `Validator<T>`. */
+export type UnwrapValidator<V> = V extends Validator<infer A> ? A : never;
+
+/** A validator for string fields in schemas. */
+export const string = {
+  validate: isString,
+  required: true,
+} as const satisfies Validator<string>;
+
+/** Transforms a validator to be optional. */
+export function optional<T>(validator: Validator<T>) {
+  return {
+    validate: (val: unknown) => {
+      return val === undefined || val === null || validator.validate(val);
+    },
+    required: false,
+  } as const satisfies Validator<T | undefined | null>;
+}
+
+/** Represents an arbitrary object schema. */
+export type Schema = Record<string, Validator<any>>;
+
+/** Extracts the required keys from `S`. */
+export type RequiredKeys<S extends Schema> = {
+  [K in keyof S]: S[K]["required"] extends true ? K : never;
+}[keyof S];
+
+/** Extracts optional keys from `S`. */
+export type OptionalKeys<S extends Schema> = {
+  [K in keyof S]: S[K]["required"] extends true ? never : K;
+}[keyof S];
+
+/** Constructs an object type corresponding to a schema. */
+export type FromSchema<S extends Schema> = {
+  [K in RequiredKeys<S>]: UnwrapValidator<S[K]>;
+} & { [K in OptionalKeys<S>]?: UnwrapValidator<S[K]> };
+
+/**
+ * Validates that `obj` satisfies at least `schema`. Additional keys are accepted.
+ *
+ * @param schema The schema to validate against.
+ * @param obj The object to validate.
+ * @returns Asserts that `obj` is of the `schema`'s type if validation is successful.
+ */
+export function validateSchema<S extends Schema>(
+  schema: S,
+  obj: UnvalidatedObject<any>,
+): obj is FromSchema<S> {
+  for (const [key, validator] of Object.entries(schema)) {
+    const hasKey = key in obj;
+
+    // If the property is required, but absent, fail.
+    if (validator.required && !hasKey) {
+      return false;
+    }
+
+    // If the property is required, but undefined or null, fail.
+    if (validator.required && (obj[key] === undefined || obj[key] === null)) {
+      return false;
+    }
+
+    // If the property is present, validate it.
+    if (hasKey && !validator.validate(obj[key])) {
+      return false;
+    }
+  }
+
+  return true;
+}

src/json/testing-util.ts

@@ -0,0 +1,106 @@
+import { ExecutionContext } from "ava";
+
+import * as json from ".";
+
+/**
+ * Constructs an object based on `schema` for unit tests.
+ * Assumes that all keys in `schema` have string values.
+ *
+ * @param includeOptional Whether to include optional properties.
+ * @param schema The schema to base the object on.
+ * @returns An object that satisfies `schema`.
+ */
+export function makeFromSchema<S extends json.Schema>(
+  includeOptional: boolean,
+  schema: S,
+): json.FromSchema<S> {
+  const result = {};
+  for (const [key, validator] of Object.entries(schema)) {
+    if (!validator.required && !includeOptional) {
+      continue;
+    }
+    result[key] = `value-for-${key}`;
+  }
+  return result as json.FromSchema<S>;
+}
+
+/** Options for `withSchemaMatrix`. */
+export interface SchemaMatrixOptions {
+  /** Whether cases where the properties are entirely absent should be excluded. */
+  excludeAbsent?: boolean;
+}
+
+/**
+ * Constructs a test matrix of possible objects for `schema`: all required properties
+ * plus all permutations of possible states for the optional properties.
+ *
+ * @param schema The schema to construct a test matrix for.
+ * @param body The test body to call with each value from the test matrix.
+ */
+export function withSchemaMatrix<S extends json.Schema>(
+  t: ExecutionContext<any>,
+  schema: S,
+  opts: SchemaMatrixOptions,
+  body: (value: json.FromSchema<S>) => void,
+): void {
+  // Construct a base object that includes all required properties.
+  const required = makeFromSchema(false, schema);
+
+  // Identify optional properties.
+  const optionalKeys: Array<keyof S> = [];
+
+  for (const [key, validator] of Object.entries(schema)) {
+    if (!validator.required) {
+      optionalKeys.push(key);
+    }
+  }
+
+  const optionalValues = (key: keyof S) => [
+    null,
+    undefined,
+    `value-for-${String(key)}`,
+  ];
+
+  // Constructs an array of test objects, starting with `required` and combining it with all
+  // possible states of each optional property. For example, with default settings:
+  //
+  // For { requiredKey: string }, we get: `[{ requiredKey: "some-string-value" }]`
+  //
+  // For { requiredKey: string, optionalKey?: string }, we get:
+  // [ { requiredKey: "some-string-value" },
+  //   { requiredKey: "some-string-value", optionalKey: undefined },
+  //   { requiredKey: "some-string-value", optionalKey: null },
+  //   { requiredKey: "some-string-value", optionalKey: "some-value" },
+  // ]
+  const permutations = (keys: Array<keyof S>) => {
+    if (keys.length === 0) return [required];
+
+    const bases = permutations(keys.slice(1));
+    const result: Array<json.FromSchema<S>> = [];
+
+    const optionalKey = keys[0];
+    for (const base of bases) {
+      if (!opts.excludeAbsent) {
+        // Optional keys can be absent entirely.
+        result.push(base);
+      }
+
+      // Or be present and have one of the `optionalValues`.
+      for (const optionalValue of optionalValues(optionalKey)) {
+        result.push({ ...base, [optionalKey]: optionalValue });
+      }
+    }
+    return result;
+  };
+
+  // Call `body` for all test cases.
+  const testCases = permutations(optionalKeys);
+  for (const testCase of testCases) {
+    try {
+      body(testCase);
+    } catch (err) {
+      t.log(testCase);
+      throw err;
+    }
+  }
+}

src/overlay/caching.test.ts

@@ -7,7 +7,7 @@ import * as sinon from "sinon";
 
 import * as actionsUtil from "../actions-util";
 import * as apiClient from "../api-client";
-import { ResolveDatabaseOutput } from "../codeql";
+import type { ResolveDatabaseOutput } from "../codeql";
 import * as gitUtils from "../git-utils";
 import { BuiltInLanguage } from "../languages";
 import { getRunnerLogger } from "../logging";
@@ -23,6 +23,7 @@ import {
   downloadOverlayBaseDatabaseFromCache,
   getCacheRestoreKeyPrefix,
   getCacheSaveKey,
+  getCodeQlVersionsForOverlayBaseDatabases,
 } from "./caching";
 import { OverlayDatabaseMode } from "./overlay-database-mode";
 
@@ -285,3 +286,134 @@ test.serial("overlay-base database cache keys remain stable", async (t) => {
     `Expected save key "${saveKey}" to start with restore key prefix "${restoreKeyPrefix}"`,
   );
 });
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases returns unique versions sorted latest first",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-javascript_python-2.23.0-abc123-1-1",
+      },
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-javascript_python-2.24.1-def456-2-1",
+      },
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-javascript_python-2.23.0-ghi789-3-1",
+      },
+    ]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["javascript", "python"],
+      logger,
+    );
+    t.deepEqual(result, ["2.24.1", "2.23.0"]);
+  },
+);
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases returns empty list when no caches exist",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["python"],
+      logger,
+    );
+    t.deepEqual(result, []);
+  },
+);
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases returns empty list when cache keys are unparseable",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-python-malformed",
+      },
+      { key: undefined },
+    ]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["python"],
+      logger,
+    );
+    t.deepEqual(result, []);
+  },
+);
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases returns the single version when only one cache exists",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-cpp-2.25.0-abc123-1-1",
+      },
+    ]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["cpp"],
+      logger,
+    );
+    t.deepEqual(result, ["2.25.0"]);
+  },
+);
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases resolves language aliases",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+    // The alias `c++` should be resolved to "cpp" and match cache entries keyed with "cpp"
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-cpp-2.25.0-abc123-1-1",
+      },
+    ]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["c++"],
+      logger,
+    );
+    t.deepEqual(result, ["2.25.0"]);
+  },
+);
+
+test.serial(
+  "getCodeQlVersionsForOverlayBaseDatabases ignores nightly versions with build metadata",
+  async (t) => {
+    const logger = getRunnerLogger(true);
+
+    sinon.stub(apiClient, "getAutomationID").resolves("test-automation-id/");
+    sinon.stub(apiClient, "listActionsCaches").resolves([
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-python-2.25.0-abc123-1-1",
+      },
+      {
+        // Nightly release with semver build metadata; should be ignored.
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-python-2.26.0+202604211234-def456-2-1",
+      },
+      {
+        key: "codeql-overlay-base-database-1-c5666c509a2d9895-python-2.24.0-ghi789-3-1",
+      },
+    ]);
+
+    const result = await getCodeQlVersionsForOverlayBaseDatabases(
+      ["python"],
+      logger,
+    );
+    t.deepEqual(result, ["2.25.0", "2.24.0"]);
+  },
+);

src/overlay/caching.ts

@@ -1,18 +1,20 @@
 import * as fs from "fs";
 
 import * as actionsCache from "@actions/cache";
+import * as semver from "semver";
 
 import {
   getRequiredInput,
   getWorkflowRunAttempt,
   getWorkflowRunID,
 } from "../actions-util";
-import { getAutomationID } from "../api-client";
+import { getAutomationID, listActionsCaches } from "../api-client";
 import { createCacheKeyHash } from "../caching-utils";
 import { type CodeQL } from "../codeql";
 import { type Config } from "../config-utils";
 import { getCommitOid } from "../git-utils";
-import { Logger, withGroupAsync } from "../logging";
+import { type Language, parseBuiltInLanguage } from "../languages";
+import { type Logger, withGroupAsync } from "../logging";
 import {
   CleanupLevel,
   getBaseDatabaseOidsFilePath,
@@ -404,7 +406,17 @@ export async function getCacheRestoreKeyPrefix(
   config: Config,
   codeQlVersion: string,
 ): Promise<string> {
-  const languages = [...config.languages].sort().join("_");
+  return `${await getCacheKeyPrefixBase(config.languages)}${codeQlVersion}-`;
+}
+
+/**
+ * Computes the cache key prefix for overlay-base databases, excluding the
+ * CodeQL version.
+ */
+async function getCacheKeyPrefixBase(
+  parsedLanguages: Language[],
+): Promise<string> {
+  const languagesComponent = [...parsedLanguages].sort().join("_");
 
   const cacheKeyComponents = {
     automationID: await getAutomationID(),
@@ -412,17 +424,97 @@ export async function getCacheRestoreKeyPrefix(
   };
   const componentsHash = createCacheKeyHash(cacheKeyComponents);
 
-  // For a cached overlay-base database to be considered compatible for overlay
-  // analysis, all components in the cache restore key must match:
-  //
   // CACHE_PREFIX: distinguishes overlay-base databases from other cache objects
   // CACHE_VERSION: cache format version
   // componentsHash: hash of additional components (see above for details)
-  // languages: the languages included in the overlay-base database
-  // codeQlVersion: CodeQL bundle version
+  // languagesComponent: the languages included in the overlay-base database
   //
-  // Technically we can also include languages and codeQlVersion in the
-  // componentsHash, but including them explicitly in the cache key makes it
-  // easier to debug and understand the cache key structure.
-  return `${CACHE_PREFIX}-${CACHE_VERSION}-${componentsHash}-${languages}-${codeQlVersion}-`;
+  // Technically we can also include languages in the componentsHash, but
+  // including them explicitly in the cache key makes it easier to debug and
+  // understand the cache key structure.
+  return `${CACHE_PREFIX}-${CACHE_VERSION}-${componentsHash}-${languagesComponent}-`;
+}
+
+/**
+ * Searches the GitHub Actions cache for overlay-base databases matching the given languages, and
+ * returns all stable CodeQL versions found across matching cache entries.
+ *
+ * Note that we do not guarantee that the cache entry for these versions of CodeQL will still be
+ * present by the time we attempt to restore the cache. We could achieve that with a download retry
+ * loop, but we expect that if there is sufficient Actions cache contention that an overlay-base
+ * cache entry for a particular CodeQL version is evicted before we can use it, then it is likely
+ * that the same thing will happen to other overlay-base cache entries, and therefore we will not be
+ * able to use overlay.
+ *
+ * @returns Unique stable CodeQL versions found in cached overlay-base databases, sorted from latest to
+ * earliest, or undefined if one of the languages is not a built-in language.
+ */
+export async function getCodeQlVersionsForOverlayBaseDatabases(
+  rawLanguages: string[],
+  logger: Logger,
+): Promise<string[] | undefined> {
+  const languages = rawLanguages.map(parseBuiltInLanguage);
+  if (languages.includes(undefined)) {
+    logger.warning(
+      "One or more provided languages are not recognized as built-in languages. " +
+        "Skipping searching for overlay-base databases in cache.",
+    );
+    return undefined;
+  }
+  const cacheKeyPrefix = await getCacheKeyPrefixBase(
+    languages.filter((l) => l !== undefined),
+  );
+
+  logger.debug(
+    `Searching for overlay-base databases in Actions cache with ` +
+      `prefix ${cacheKeyPrefix}`,
+  );
+
+  const caches = await listActionsCaches(cacheKeyPrefix);
+
+  if (caches.length === 0) {
+    logger.info("No overlay-base databases found in Actions cache.");
+    return [];
+  }
+
+  logger.info(
+    `Found ${caches.length} overlay-base ` +
+      `${caches.length === 1 ? "database" : "databases"} in the Actions cache.`,
+  );
+
+  // Parse CodeQL versions from cache keys, matching only stable releases.
+  //
+  // After the prefix, the remaining key format starts with `${codeQlVersion}-`. Nightlies will have
+  // a suffix like `+202604201548` that will break the match.
+  //
+  // Caveat: this relies on the fact that we haven't released any CodeQL bundles with the
+  // `x.y.z-<pre-release>` semver format which does not interact well with the current overlay base
+  // DB cache key format.
+  const versionRegex = /^([\d.]+)-/;
+  const versionSet = new Set<string>();
+
+  for (const cache of caches) {
+    if (!cache.key) continue;
+    const suffix = cache.key.substring(cacheKeyPrefix.length);
+    const match = suffix.match(versionRegex);
+    if (match && semver.valid(match[1])) {
+      versionSet.add(match[1]);
+    }
+  }
+
+  if (versionSet.size === 0) {
+    logger.info(
+      "Could not parse any CodeQL versions from overlay-base database " +
+        "cache keys.",
+    );
+    return [];
+  }
+
+  const versions = [...versionSet].sort(semver.rcompare);
+
+  logger.info(
+    `Found overlay databases for the following CodeQL versions in the Actions cache: ${versions.join(", ")}`,
+  );
+
+  return versions;
 }

src/start-proxy-action.ts

@@ -198,6 +198,7 @@ async function startProxy(
     .map((credential) => ({
       type: credential.type,
       url: credential.url,
+      "replaces-base": credential["replaces-base"],
     }));
   core.setOutput("proxy_urls", JSON.stringify(registry_urls));
 

src/start-proxy.test.ts

@@ -8,6 +8,8 @@ import sinon from "sinon";
 import * as apiClient from "./api-client";
 import * as defaults from "./defaults.json";
 import { setUpFeatureFlagTests } from "./feature-flags/testing-util";
+import { UnvalidatedObject, validateSchema } from "./json";
+import { makeFromSchema } from "./json/testing-util";
 import { BuiltInLanguage } from "./languages";
 import { getRunnerLogger, Logger } from "./logging";
 import * as startProxyExports from "./start-proxy";
@@ -349,131 +351,46 @@ test("getCredentials throws an error when non-printable characters are used", as
   }
 });
 
-const validAzureCredential: startProxyExports.AzureConfig = {
-  "tenant-id": "12345678-1234-1234-1234-123456789012",
-  "client-id": "abcdef01-2345-6789-abcd-ef0123456789",
-};
+for (const oidcSchemaInfo of startProxyExports.oidcSchemas) {
+  test(`getCredentials throws when non-printable characters are used (${oidcSchemaInfo.name} OIDC)`, (t) => {
+    const validCredential = makeFromSchema(true, oidcSchemaInfo.schema);
+    for (const key of Object.keys(validCredential)) {
+      const invalidAuthConfig = {
+        ...validCredential,
+        [key]: "123\x00",
+      };
+      const invalidCredential: startProxyExports.RawCredential = {
+        type: "nuget_feed",
+        host: `${key}.nuget.pkg.github.com`,
+        ...invalidAuthConfig,
+      };
+      const credentialsInput = toEncodedJSON([invalidCredential]);
 
-const validAwsCredential: startProxyExports.AWSConfig = {
-  "aws-region": "us-east-1",
-  "account-id": "123456789012",
-  "role-name": "MY_ROLE",
-  domain: "MY_DOMAIN",
-  "domain-owner": "987654321098",
-  audience: "custom-audience",
-};
-
-const validJFrogCredential: startProxyExports.JFrogConfig = {
-  "jfrog-oidc-provider-name": "MY_PROVIDER",
-  audience: "jfrog-audience",
-  "identity-mapping-name": "my-mapping",
-};
-
-test("getCredentials throws an error when non-printable characters are used for Azure OIDC", (t) => {
-  for (const key of Object.keys(validAzureCredential)) {
-    const invalidAzureCredential = {
-      ...validAzureCredential,
-      [key]: "123\x00",
-    };
-    const invalidCredential: startProxyExports.RawCredential = {
-      type: "nuget_feed",
-      host: `${key}.nuget.pkg.github.com`,
-      ...invalidAzureCredential,
-    };
-    const credentialsInput = toEncodedJSON([invalidCredential]);
-
-    t.throws(
-      () =>
-        startProxyExports.getCredentials(
-          getRunnerLogger(true),
-          undefined,
-          credentialsInput,
-          undefined,
-        ),
-      {
-        message:
-          "Invalid credentials - fields must contain only printable characters",
-      },
-    );
-  }
-});
-
-test("getCredentials throws an error when non-printable characters are used for AWS OIDC", (t) => {
-  for (const key of Object.keys(validAwsCredential)) {
-    const invalidAwsCredential = {
-      ...validAwsCredential,
-      [key]: "123\x00",
-    };
-    const invalidCredential: startProxyExports.RawCredential = {
-      type: "nuget_feed",
-      host: `${key}.nuget.pkg.github.com`,
-      ...invalidAwsCredential,
-    };
-    const credentialsInput = toEncodedJSON([invalidCredential]);
-
-    t.throws(
-      () =>
-        startProxyExports.getCredentials(
-          getRunnerLogger(true),
-          undefined,
-          credentialsInput,
-          undefined,
-        ),
-      {
-        message:
-          "Invalid credentials - fields must contain only printable characters",
-      },
-    );
-  }
-});
-
-test("getCredentials throws an error when non-printable characters are used for JFrog OIDC", (t) => {
-  for (const key of Object.keys(validJFrogCredential)) {
-    const invalidJFrogCredential = {
-      ...validJFrogCredential,
-      [key]: "123\x00",
-    };
-    const invalidCredential: startProxyExports.RawCredential = {
-      type: "nuget_feed",
-      host: `${key}.nuget.pkg.github.com`,
-      ...invalidJFrogCredential,
-    };
-    const credentialsInput = toEncodedJSON([invalidCredential]);
-
-    t.throws(
-      () =>
-        startProxyExports.getCredentials(
-          getRunnerLogger(true),
-          undefined,
-          credentialsInput,
-          undefined,
-        ),
-      {
-        message:
-          "Invalid credentials - fields must contain only printable characters",
-      },
-    );
-  }
-});
+      t.throws(
+        () =>
+          startProxyExports.getCredentials(
+            getRunnerLogger(true),
+            undefined,
+            credentialsInput,
+            undefined,
+          ),
+        {
+          message:
+            "Invalid credentials - fields must contain only printable characters",
+        },
+      );
+    }
+  });
+}
 
 test("getCredentials accepts OIDC configurations", (t) => {
-  const oidcConfigurations = [
-    {
+  const oidcConfigurations = startProxyExports.oidcSchemas.map(
+    (schemaInfo) => ({
       type: "nuget_feed",
-      host: "azure.pkg.github.com",
-      ...validAzureCredential,
-    },
-    {
-      type: "nuget_feed",
-      host: "aws.pkg.github.com",
-      ...validAwsCredential,
-    },
-    {
-      type: "nuget_feed",
-      host: "jfrog.pkg.github.com",
-      ...validJFrogCredential,
-    },
-  ];
+      host: `${schemaInfo.name.toLowerCase()}.pkg.github.com`,
+      ...makeFromSchema(true, schemaInfo.schema),
+    }),
+  );
 
   const credentials = startProxyExports.getCredentials(
     getRunnerLogger(true),
@@ -481,12 +398,20 @@ test("getCredentials accepts OIDC configurations", (t) => {
     toEncodedJSON(oidcConfigurations),
     BuiltInLanguage.csharp,
   );
-  t.is(credentials.length, 3);
+  t.is(credentials.length, startProxyExports.oidcSchemas.length);
 
   t.assert(credentials.every((c) => c.type === "nuget_feed"));
-  t.assert(credentials.some((c) => startProxyExports.isAzureConfig(c)));
-  t.assert(credentials.some((c) => startProxyExports.isAWSConfig(c)));
-  t.assert(credentials.some((c) => startProxyExports.isJFrogConfig(c)));
+
+  for (const oidcSchemaInfo of startProxyExports.oidcSchemas) {
+    t.assert(
+      credentials.some((c) =>
+        validateSchema(
+          oidcSchemaInfo.schema,
+          c as unknown as UnvalidatedObject<any>,
+        ),
+      ),
+    );
+  }
 });
 
 const getCredentialsMacro = test.macro({
@@ -532,7 +457,7 @@ test(
     t.is(results[0].type, "git_server");
     t.is(results[0].host, "https://github.com/");
 
-    if (startProxyExports.isUsernamePassword(results[0])) {
+    if (startProxyExports.hasUsernameAndPassword(results[0])) {
       t.assert(results[0].password?.startsWith("ghp_"));
     } else {
       t.fail("Expected a `UsernamePassword`-based credential.");
@@ -563,7 +488,7 @@ test(
     t.is(results[0].type, "git_server");
     t.is(results[0].host, "https://github.com/");
 
-    if (startProxyExports.isUsernamePassword(results[0])) {
+    if (startProxyExports.hasUsernameAndPassword(results[0])) {
       t.assert(results[0].password?.startsWith("ghp_"));
     } else {
       t.fail("Expected a `UsernamePassword`-based credential.");
@@ -639,6 +564,76 @@ test(
   },
 );
 
+test("getCredentials validates 'replaces-base' correctly", async (t) => {
+  // Valid cases.
+  const credentialsInput = toEncodedJSON([
+    {
+      type: "maven_repository",
+      host: "maven1.pkg.github.com",
+      token: "abc",
+      "replaces-base": false,
+    },
+    {
+      type: "maven_repository",
+      host: "maven2.pkg.github.com",
+      token: "def",
+      "replaces-base": true,
+    },
+    {
+      type: "maven_repository",
+      host: "maven3.pkg.github.com",
+      token: "ghi",
+    },
+  ]);
+
+  const credentials = startProxyExports.getCredentials(
+    getRunnerLogger(true),
+    undefined,
+    credentialsInput,
+    BuiltInLanguage.java,
+    false,
+  );
+
+  t.is(credentials.length, 3);
+  t.true(credentials.some((c) => c["replaces-base"] === true));
+  t.true(credentials.some((c) => c["replaces-base"] === false));
+  t.true(credentials.some((c) => c["replaces-base"] === undefined));
+
+  // Invalid cases.
+  const baseInvalid = {
+    type: "maven_repository",
+    host: "maven4.pkg.github.com",
+    token: "jkl",
+  };
+  t.throws(() =>
+    startProxyExports.getCredentials(
+      getRunnerLogger(true),
+      undefined,
+      toEncodedJSON([{ ...baseInvalid, "replaces-base": null }]),
+      BuiltInLanguage.actions,
+      false,
+    ),
+  );
+  t.throws(() =>
+    startProxyExports.getCredentials(
+      getRunnerLogger(true),
+      undefined,
+      toEncodedJSON([{ ...baseInvalid, "replaces-base": 123 }]),
+      BuiltInLanguage.actions,
+      false,
+    ),
+  );
+  t.throws(() =>
+    startProxyExports.getCredentials(
+      getRunnerLogger(true),
+      undefined,
+      toEncodedJSON([{ ...baseInvalid, "replaces-base": "true" }]),
+      BuiltInLanguage.actions,
+      false,
+    ),
+  );
+});
+
 test("getCredentials returns all credentials for Actions when using LANGUAGE_TO_REGISTRY_TYPE", async (t) => {
   const credentialsInput = toEncodedJSON(mixedCredentials);
 

src/start-proxy.ts

@@ -24,20 +24,12 @@ import {
   Address,
   Registry,
   Credential,
-  AuthConfig,
-  isToken,
-  isAzureConfig,
-  Token,
-  UsernamePassword,
-  AzureConfig,
-  isAWSConfig,
-  AWSConfig,
-  isJFrogConfig,
-  JFrogConfig,
-  isUsernamePassword,
+  hasToken,
+  hasUsernameAndPassword,
   hasUsername,
   RawCredential,
 } from "./start-proxy/types";
+import { getAuthConfig } from "./start-proxy/validation";
 import {
   ActionName,
   createStatusReportBase,
@@ -251,75 +243,6 @@ function getRegistryAddress(
   }
 }
 
-/** Extracts an `AuthConfig` value from `config`. */
-export function getAuthConfig(
-  config: json.UnvalidatedObject<AuthConfig>,
-): AuthConfig {
-  // Start by checking for the OIDC configurations, since they have required properties
-  // which we can use to identify them.
-  if (isAzureConfig(config)) {
-    return {
-      "tenant-id": config["tenant-id"],
-      "client-id": config["client-id"],
-    } satisfies AzureConfig;
-  } else if (isAWSConfig(config)) {
-    return {
-      "aws-region": config["aws-region"],
-      "account-id": config["account-id"],
-      "role-name": config["role-name"],
-      domain: config.domain,
-      "domain-owner": config["domain-owner"],
-      audience: config.audience,
-    } satisfies AWSConfig;
-  } else if (isJFrogConfig(config)) {
-    return {
-      "jfrog-oidc-provider-name": config["jfrog-oidc-provider-name"],
-      "identity-mapping-name": config["identity-mapping-name"],
-      audience: config.audience,
-    } satisfies JFrogConfig;
-  } else if (isToken(config)) {
-    // There are three scenarios for non-OIDC authentication based on the registry type:
-    //
-    // 1. `username`+`token`
-    // 2. A `token` that combines the username and actual token, separated by ':'.
-    // 3. `username`+`password`
-    //
-    // In all three cases, all fields are optional. If the `token` field is present,
-    // we accept the configuration as a `Token` typed configuration, with the `token`
-    // value and an optional `username`. Otherwise, we accept the configuration
-    // typed as `UsernamePassword` (in the `else` clause below) with optional
-    // username and password. I.e. a private registry type that uses 1. or 2.,
-    // but has no `token` configured, will get accepted as `UsernamePassword` here.
-
-    if (isDefined(config.token)) {
-      // Mask token to reduce chance of accidental leakage in logs, if we have one.
-      core.setSecret(config.token);
-    }
-
-    return { username: config.username, token: config.token } satisfies Token;
-  } else {
-    let username: string | undefined = undefined;
-    let password: string | undefined = undefined;
-
-    // Both "username" and "password" are optional. If we have reached this point, we need
-    // to validate which of them are present and that they have the correct type if so.
-    if ("password" in config && json.isString(config.password)) {
-      // Mask password to reduce chance of accidental leakage in logs, if we have one.
-      core.setSecret(config.password);
-      password = config.password;
-    }
-    if ("username" in config && json.isString(config.username)) {
-      username = config.username;
-    }
-
-    // Return the `UsernamePassword` object. Both username and password may be undefined.
-    return {
-      username,
-      password,
-    } satisfies UsernamePassword;
-  }
-}
-
 // getCredentials returns registry credentials from action inputs.
 // It prefers `registries_credentials` over `registry_secrets`.
 // If neither is set, it returns an empty array.
@@ -408,11 +331,11 @@ export function getCredentials(
     const noUsername =
       !hasUsername(authConfig) || !isDefined(authConfig.username);
     const passwordIsPAT =
-      isUsernamePassword(authConfig) &&
+      hasUsernameAndPassword(authConfig) &&
       isDefined(authConfig.password) &&
       isPAT(authConfig.password);
     const tokenIsPAT =
-      isToken(authConfig) &&
+      hasToken(authConfig) &&
       isDefined(authConfig.token) &&
       isPAT(authConfig.token);
 
@@ -424,8 +347,25 @@ export function getCredentials(
       );
     }
 
+    // Construct the base credential object.
+    const baseCredential: Omit<Registry, keyof Address> = { type: e.type };
+
+    // If "replaces-base" is present, it must be a boolean.
+    if ("replaces-base" in e) {
+      if (
+        isDefined(e["replaces-base"]) &&
+        typeof e["replaces-base"] === "boolean"
+      ) {
+        baseCredential["replaces-base"] = e["replaces-base"];
+      } else {
+        throw new ConfigurationError(
+          "Invalid credentials - 'replaces-base' must be a boolean",
+        );
+      }
+    }
+
     out.push({
-      type: e.type,
+      ...baseCredential,
       ...authConfig,
       ...address,
     });

src/start-proxy/types.test.ts

@@ -1,5 +1,6 @@
 import test from "ava";
 
+import { makeFromSchema, withSchemaMatrix } from "../json/testing-util";
 import { setupTests } from "../testing-utils";
 
 import * as types from "./types";
@@ -26,6 +27,38 @@ const validJFrogCredential: types.JFrogConfig = {
   "identity-mapping-name": "my-mapping",
 };
 
+test("hasUsername", (t) => {
+  // Reject the case where `username` is missing.
+  t.false(types.hasUsername({}));
+
+  // Test all cases where `username` is present.
+  withSchemaMatrix(
+    t,
+    types.usernameSchema,
+    { excludeAbsent: true },
+    (value) => {
+      t.true(types.hasUsername(value));
+    },
+  );
+});
+
+test("hasUsernameAndPassword", (t) => {
+  // Reject cases where `username` or `password` are missing.
+  t.false(types.hasUsernameAndPassword({}));
+  t.false(types.hasUsernameAndPassword({ username: "foo" }));
+  t.false(types.hasUsernameAndPassword({ password: "foo" }));
+
+  // Test all cases where both `username` and `password` are present.
+  withSchemaMatrix(
+    t,
+    types.usernamePasswordSchema,
+    { excludeAbsent: true },
+    (value) => {
+      t.true(types.hasUsernameAndPassword(value));
+    },
+  );
+});
+
 test("credentialToStr - pretty-prints valid username+password configurations", (t) => {
   const secret = "password123";
   const credential: types.Credential = {
@@ -107,13 +140,46 @@ test("credentialToStr - pretty-prints valid JFrog OIDC configurations", (t) => {
   );
 });
 
+test("credentialToStr - pretty-prints valid Cloudsmith OIDC configurations", (t) => {
+  const credential: types.Credential = {
+    type: "maven_credential",
+    url: "https://localhost",
+    ...(makeFromSchema(
+      true,
+      types.cloudsmithConfigSchema,
+    ) as types.CloudsmithConfig),
+  };
+
+  const str = types.credentialToStr(credential);
+
+  t.is(
+    "Type: maven_credential; Url: https://localhost; Cloudsmith Namespace: value-for-namespace; Cloudsmith Service Slug: value-for-service-slug; Cloudsmith API Host: value-for-api-host;",
+    str,
+  );
+});
+
+test("credentialToStr - pretty-prints valid GCP OIDC configurations", (t) => {
+  const credential: types.Credential = {
+    type: "maven_credential",
+    url: "https://localhost",
+    ...(makeFromSchema(true, types.gcpConfigSchema) as types.GCPConfig),
+  };
+
+  const str = types.credentialToStr(credential);
+
+  t.is(
+    "Type: maven_credential; Url: https://localhost; GCP Workload Identity Provider: value-for-workload-identity-provider; GCP Service Account: value-for-service-account; GCP Audience: value-for-audience;",
+    str,
+  );
+});
+
 test("credentialToStr - hides passwords", (t) => {
   const secret = "password123";
   const credential = {
     type: "maven_credential",
     password: secret,
     url: "https://localhost",
-  };
+  } satisfies types.Credential;
 
   const str = types.credentialToStr(credential);
 
@@ -127,7 +193,7 @@ test("credentialToStr - hides tokens", (t) => {
     type: "maven_credential",
     token: secret,
     url: "https://localhost",
-  };
+  } satisfies types.Credential;
 
   const str = types.credentialToStr(credential);
 

src/start-proxy/types.ts

@@ -9,144 +9,177 @@ import { isDefined } from "../util";
  */
 export type RawCredential = UnvalidatedObject<Credential>;
 
-/** Usernames may be present for both authentication with tokens or passwords. */
-export type Username = {
+/** A schema for credential objects with a username. */
+export const usernameSchema = {
   /** The username needed to authenticate to the package registry, if any. */
-  username?: string;
-};
+  username: json.optional(json.string),
+} as const satisfies json.Schema;
 
-/** Decides whether `config` has a username. */
+/** Usernames may be present for both authentication with tokens or passwords. */
+export type Username = json.FromSchema<typeof usernameSchema>;
+
+/**
+ * Narrows `config` to `Username` if `config` has a `username` property.
+ * Not used for validation. Assumes that `config` is already a validated `AuthConfig`.
+ */
 export function hasUsername(config: AuthConfig): config is Username {
   return "username" in config;
 }
 
+/** A schema for credential objects with a username and password. */
+export const usernamePasswordSchema = {
+  /** The password needed to authenticate to the package registry, if any. */
+  password: json.optional(json.string),
+  ...usernameSchema,
+} as const satisfies json.Schema;
+
 /**
  * Fields expected for authentication based on a username and password.
  * Both username and password are optional.
  */
-export type UsernamePassword = {
-  /** The password needed to authenticate to the package registry, if any. */
-  password?: string;
-} & Username;
+export type UsernamePassword = json.FromSchema<typeof usernamePasswordSchema>;
 
-/** Decides whether `config` is based on a username and password. */
-export function isUsernamePassword(
+/**
+ * Narrows `config` to `UsernamePassword` if it has a `username` and `password` property.
+ * Not used for validation. Assumes that `config` is already a validated `AuthConfig`.
+ */
+export function hasUsernameAndPassword(
   config: AuthConfig,
 ): config is UsernamePassword {
   return hasUsername(config) && "password" in config;
 }
 
+/** A schema for credential objects for token-based authentication. */
+export const tokenSchema = {
+  /** The token needed to authenticate to the package registry, if any. */
+  token: json.optional(json.string),
+  ...usernameSchema,
+} as const satisfies json.Schema;
+
 /**
  * Fields expected for token-based authentication.
  * Both username and token are optional.
  */
-export type Token = {
-  /** The token needed to authenticate to the package registry, if any. */
-  token?: string;
-} & Username;
+export type Token = json.FromSchema<typeof tokenSchema>;
+
+/**
+ * Narrows `config` to `Token` if it has a `token` property.
+ * Not used for validation. Assumes that `config` is already a validated `AuthConfig`.
+ */
+export function hasToken(config: AuthConfig): config is Token {
+  return "token" in config;
+}
 
 /** Decides whether `config` is token-based. */
 export function isToken(
   config: UnvalidatedObject<AuthConfig>,
 ): config is Token {
-  // The "username" field is optional, but should be a string if present.
-  if ("username" in config && !json.isStringOrUndefined(config.username)) {
-    return false;
-  }
-
-  // The "token" field is required, and must be a string or undefined.
-  return "token" in config && json.isStringOrUndefined(config.token);
+  return "token" in config && json.validateSchema(tokenSchema, config);
 }
 
+/** A schema for Azure OIDC configurations. */
+export const azureConfigSchema = {
+  "tenant-id": json.string,
+  "client-id": json.string,
+} as const satisfies json.Schema;
+
 /** Configuration for Azure OIDC. */
-export type AzureConfig = { "tenant-id": string; "client-id": string };
+export type AzureConfig = json.FromSchema<typeof azureConfigSchema>;
 
 /** Decides whether `config` is an Azure OIDC configuration. */
 export function isAzureConfig(
   config: UnvalidatedObject<AuthConfig>,
 ): config is AzureConfig {
-  return (
-    "tenant-id" in config &&
-    "client-id" in config &&
-    isDefined(config["tenant-id"]) &&
-    isDefined(config["client-id"]) &&
-    json.isString(config["tenant-id"]) &&
-    json.isString(config["client-id"])
-  );
+  return json.validateSchema(azureConfigSchema, config);
 }
 
+/** A schema for AWS OIDC configurations. */
+export const awsConfigSchema = {
+  "aws-region": json.string,
+  "account-id": json.string,
+  "role-name": json.string,
+  domain: json.string,
+  "domain-owner": json.string,
+  audience: json.optional(json.string),
+} as const satisfies json.Schema;
+
 /** Configuration for AWS OIDC. */
-export type AWSConfig = {
-  "aws-region": string;
-  "account-id": string;
-  "role-name": string;
-  domain: string;
-  "domain-owner": string;
-  audience?: string;
-};
+export type AWSConfig = json.FromSchema<typeof awsConfigSchema>;
 
 /** Decides whether `config` is an AWS OIDC configuration. */
 export function isAWSConfig(
   config: UnvalidatedObject<AuthConfig>,
 ): config is AWSConfig {
-  // All of these properties are required.
-  const requiredProperties = [
-    "aws-region",
-    "account-id",
-    "role-name",
-    "domain",
-    "domain-owner",
-  ];
-
-  for (const property of requiredProperties) {
-    if (
-      !(property in config) ||
-      !isDefined(config[property]) ||
-      !json.isString(config[property])
-    ) {
-      return false;
-    }
-  }
-
-  // The "audience" field is optional, but should be a string if present.
-  if ("audience" in config && !json.isStringOrUndefined(config.audience)) {
-    return false;
-  }
-
-  return true;
+  return json.validateSchema(awsConfigSchema, config);
 }
 
+/** A schema for JFrog OIDC configurations. */
+export const jfrogConfigSchema = {
+  "jfrog-oidc-provider-name": json.string,
+  audience: json.optional(json.string),
+  "identity-mapping-name": json.optional(json.string),
+} as const satisfies json.Schema;
+
 /** Configuration for JFrog OIDC. */
-export type JFrogConfig = {
-  "jfrog-oidc-provider-name": string;
-  audience?: string;
-  "identity-mapping-name"?: string;
-};
+export type JFrogConfig = json.FromSchema<typeof jfrogConfigSchema>;
 
 /** Decides whether `config` is a JFrog OIDC configuration. */
 export function isJFrogConfig(
   config: UnvalidatedObject<AuthConfig>,
 ): config is JFrogConfig {
-  // The "audience" and "identity-mapping-name" fields are optional, but should be strings if present.
-  if ("audience" in config && !json.isStringOrUndefined(config.audience)) {
-    return false;
-  }
-  if (
-    "identity-mapping-name" in config &&
-    !json.isStringOrUndefined(config["identity-mapping-name"])
-  ) {
-    return false;
-  }
-
-  return (
-    "jfrog-oidc-provider-name" in config &&
-    isDefined(config["jfrog-oidc-provider-name"]) &&
-    json.isString(config["jfrog-oidc-provider-name"])
-  );
+  return json.validateSchema(jfrogConfigSchema, config);
 }
 
+/** A schema for Cloudsmith OIDC configurations. */
+export const cloudsmithConfigSchema = {
+  namespace: json.string,
+  "service-slug": json.string,
+  "api-host": json.string,
+} as const satisfies json.Schema;
+
+/** Configuration for Cloudsmith OIDC. */
+export type CloudsmithConfig = json.FromSchema<typeof cloudsmithConfigSchema>;
+
+/** Decides whether `config` is a Cloudsmith OIDC configuration. */
+export function isCloudsmithConfig(
+  config: UnvalidatedObject<AuthConfig>,
+): config is CloudsmithConfig {
+  return json.validateSchema(cloudsmithConfigSchema, config);
+}
+
+/** A schema for GCP OIDC configurations. */
+export const gcpConfigSchema = {
+  "workload-identity-provider": json.string,
+  "service-account": json.optional(json.string),
+  audience: json.optional(json.string),
+} as const satisfies json.Schema;
+
+/** Configuration for GCP OIDC. */
+export type GCPConfig = json.FromSchema<typeof gcpConfigSchema>;
+
+/** Decides whether `config` is a GCP OIDC configuration. */
+export function isGCPConfig(
+  config: UnvalidatedObject<AuthConfig>,
+): config is GCPConfig {
+  return json.validateSchema(gcpConfigSchema, config);
+}
+
+/** An array of all OIDC configuration schemas along with output-friendly names. */
+export const oidcSchemas = [
+  { schema: azureConfigSchema, name: "Azure" },
+  { schema: awsConfigSchema, name: "AWS" },
+  { schema: jfrogConfigSchema, name: "JFrog" },
+  { schema: cloudsmithConfigSchema, name: "Cloudsmith" },
+  { schema: gcpConfigSchema, name: "GCP" },
+];
+
 /** Represents all supported OIDC configurations. */
-export type OIDC = AzureConfig | AWSConfig | JFrogConfig;
+export type OIDC =
+  | AzureConfig
+  | AWSConfig
+  | JFrogConfig
+  | CloudsmithConfig
+  | GCPConfig;
 
 /** All authentication-related fields. */
 export type AuthConfig = UsernamePassword | Token | OIDC;
@@ -165,7 +198,7 @@ export type Credential = AuthConfig & Registry;
 export function credentialToStr(credential: Credential): string {
   let result: string = `Type: ${credential.type};`;
 
-  const appendIfDefined = (name: string, val: string | undefined) => {
+  const appendIfDefined = (name: string, val: string | undefined | null) => {
     if (isDefined(val)) {
       result += ` ${name}: ${val};`;
     }
@@ -184,7 +217,7 @@ export function credentialToStr(credential: Credential): string {
       isDefined(credential.password) ? "***" : undefined,
     );
   }
-  if (isToken(credential)) {
+  if (hasToken(credential)) {
     appendIfDefined("Token", isDefined(credential.token) ? "***" : undefined);
   }
 
@@ -205,6 +238,17 @@ export function credentialToStr(credential: Credential): string {
       credential["identity-mapping-name"],
     );
     appendIfDefined("JFrog Audience", credential.audience);
+  } else if (isCloudsmithConfig(credential)) {
+    appendIfDefined("Cloudsmith Namespace", credential.namespace);
+    appendIfDefined("Cloudsmith Service Slug", credential["service-slug"]);
+    appendIfDefined("Cloudsmith API Host", credential["api-host"]);
+  } else if (isGCPConfig(credential)) {
+    appendIfDefined(
+      "GCP Workload Identity Provider",
+      credential["workload-identity-provider"],
+    );
+    appendIfDefined("GCP Service Account", credential["service-account"]);
+    appendIfDefined("GCP Audience", credential.audience);
   }
 
   return result;
@@ -214,6 +258,8 @@ export function credentialToStr(credential: Credential): string {
 export type Registry = {
   /** The type of the package registry. */
   type: string;
+  /** Whether the registry replaces the base registry for the ecosystem. */
+  "replaces-base"?: boolean;
 } & Address;
 
 // If a registry has an `url`, then that takes precedence over the `host` which may or may

src/start-proxy/validation.test.ts

@@ -0,0 +1,69 @@
+import test from "ava";
+
+import * as json from "../json";
+import { makeFromSchema } from "../json/testing-util";
+import { setupTests } from "../testing-utils";
+
+import * as types from "./types";
+import { getAuthConfig } from "./validation";
+
+setupTests(test);
+
+for (const schemaTest of types.oidcSchemas) {
+  for (const includeOptional of [true, false]) {
+    const minimalName = includeOptional ? "full" : "minimal";
+
+    test(`getAuthConfig - ${schemaTest.name} - ${minimalName}`, async (t) => {
+      const config = makeFromSchema(includeOptional, schemaTest.schema);
+
+      t.deepEqual(
+        getAuthConfig({
+          ...config,
+          unexpected: "unexpected-value",
+        } as unknown as json.UnvalidatedObject<types.AuthConfig>),
+        config,
+      );
+    });
+  }
+}
+
+test("getAuthConfig - token", async (t) => {
+  const config = makeFromSchema(true, types.tokenSchema);
+
+  t.deepEqual(
+    getAuthConfig({
+      ...config,
+      unexpected: "unexpected-value",
+    } as json.UnvalidatedObject<types.AuthConfig>),
+    config,
+  );
+});
+
+test("getAuthConfig - username and password", async (t) => {
+  const config = makeFromSchema(true, types.usernamePasswordSchema);
+
+  t.deepEqual(
+    getAuthConfig({
+      ...config,
+      unexpected: "unexpected-value",
+    } as json.UnvalidatedObject<types.AuthConfig>),
+    config,
+  );
+});
+
+test("getAuthConfig - empty", async (t) => {
+  const config = makeFromSchema(false, types.usernamePasswordSchema);
+
+  // Since the purpose of constructing the `AuthConfig` values is for
+  // serialisation to JSON so that they can be passed to the proxy as configuration,
+  // we only care that the stringified JSON representations are the same.
+  t.deepEqual(
+    JSON.stringify(
+      getAuthConfig({
+        ...config,
+        unexpected: "unexpected-value",
+      } as json.UnvalidatedObject<types.AuthConfig>),
+    ),
+    JSON.stringify({}),
+  );
+});

src/start-proxy/validation.ts

@@ -0,0 +1,81 @@
+import * as core from "@actions/core";
+
+import * as json from "../json";
+import { isDefined } from "../util";
+
+import type { AuthConfig, UsernamePassword } from "./types";
+import * as types from "./types";
+
+/** Constructs a new object from `obj` with only keys that exist in `schema`. */
+export function cloneCredential<S extends json.Schema>(
+  schema: S,
+  obj: json.FromSchema<S>,
+): json.FromSchema<S> {
+  const result = {};
+
+  for (const key of Object.keys(schema)) {
+    // Skip keys that don't exist or don't have a value.
+    if (!isDefined(obj[key])) {
+      continue;
+    }
+    result[key] = obj[key];
+  }
+
+  return result as json.FromSchema<S>;
+}
+
+/** Extracts an `AuthConfig` value from `config`. */
+export function getAuthConfig(
+  config: json.UnvalidatedObject<AuthConfig>,
+): AuthConfig {
+  // Start by checking for the OIDC configurations, since they have required properties
+  // which we can use to identify them.
+  for (const oidcSchema of types.oidcSchemas) {
+    if (json.validateSchema(oidcSchema.schema, config)) {
+      return cloneCredential(oidcSchema.schema, config);
+    }
+  }
+
+  // Otherwise, try the basic configuration types.
+  if (types.isToken(config)) {
+    // There are three scenarios for non-OIDC authentication based on the registry type:
+    //
+    // 1. `username`+`token`
+    // 2. A `token` that combines the username and actual token, separated by ':'.
+    // 3. `username`+`password`
+    //
+    // In all three cases, all fields are optional. If the `token` field is present,
+    // we accept the configuration as a `Token` typed configuration, with the `token`
+    // value and an optional `username`. Otherwise, we accept the configuration
+    // typed as `UsernamePassword` (in the `else` clause below) with optional
+    // username and password. I.e. a private registry type that uses 1. or 2.,
+    // but has no `token` configured, will get accepted as `UsernamePassword` here.
+
+    if (isDefined(config.token)) {
+      // Mask token to reduce chance of accidental leakage in logs, if we have one.
+      core.setSecret(config.token);
+    }
+
+    return cloneCredential(types.tokenSchema, config);
+  } else {
+    let username: string | undefined = undefined;
+    let password: string | undefined = undefined;
+
+    // Both "username" and "password" are optional. If we have reached this point, we need
+    // to validate which of them are present and that they have the correct type if so.
+    if ("password" in config && json.isString(config.password)) {
+      // Mask password to reduce chance of accidental leakage in logs, if we have one.
+      core.setSecret(config.password);
+      password = config.password;
+    }
+    if ("username" in config && json.isString(config.username)) {
+      username = config.username;
+    }
+
+    // Return the `UsernamePassword` object. Both username and password may be undefined.
+    return {
+      username,
+      password,
+    } satisfies UsernamePassword;
+  }
+}