Move diff-range extension pack generation into testable function

lib/analyze-action.js

@@ -91324,6 +91324,29 @@ async function setupDiffInformedQueryRun(branches, logger) {
     }
   );
 }
+function diffRangeExtensionPackContents(ranges) {
+  const header = `
+extensions:
+  - addsTo:
+      pack: codeql/util
+      extensible: restrictAlertsTo
+      checkPresence: false
+    data:
+`;
+  let data = ranges.map(
+    (range) => (
+      // Using yaml.dump() with `forceQuotes: true` ensures that all special
+      // characters are escaped, and that the path is always rendered as a
+      // quoted string on a single line.
+      `      - [${dump(range.path, { forceQuotes: true }).trim()}, ${range.startLine}, ${range.endLine}]
+`
+    )
+  ).join("");
+  if (!data) {
+    data = '      - ["", 0, 0]\n';
+  }
+  return header + data;
+}
 function writeDiffRangeDataExtensionPack(logger, ranges) {
   if (ranges === void 0) {
     return void 0;
@@ -91345,27 +91368,7 @@ dataExtensions:
   - pr-diff-range.yml
 `
   );
-  const header = `
-extensions:
-  - addsTo:
-      pack: codeql/util
-      extensible: restrictAlertsTo
-      checkPresence: false
-    data:
-`;
-  let data = ranges.map(
-    (range) => (
-      // Using yaml.dump() with `forceQuotes: true` ensures that all special
-      // characters are escaped, and that the path is always rendered as a
-      // quoted string on a single line.
-      `      - [${dump(range.path, { forceQuotes: true }).trim()}, ${range.startLine}, ${range.endLine}]
-`
-    )
-  ).join("");
-  if (!data) {
-    data = '      - ["", 0, 0]\n';
-  }
-  const extensionContents = header + data;
+  const extensionContents = diffRangeExtensionPackContents(ranges);
   const extensionFilePath = path12.join(diffRangeDir, "pr-diff-range.yml");
   fs12.writeFileSync(extensionFilePath, extensionContents);
   logger.debug(