Add filename clarity and docs link (duckduckgo#3415)

* Add filename clarity and docs link

* Add sample config change

* Remove test

* Lint fix

Author: jonathanKingston

.github/scripts/diff-directories.js

@@ -114,16 +114,46 @@ ${fileDiff}
         .map((key) => {
             const rollup = rollupGrouping[key];
             let outString = '';
-            let title = rollup.files[0];
+            let title;
+
+            // Create descriptive title based on file count and type
+            if (rollup.files.length === 1) {
+                title = rollup.files[0];
+            } else {
+                const fileCount = rollup.files.length;
+                if (key === 'identical') {
+                    title = `${fileCount} files identical`;
+                } else if (key === 'old 1') {
+                    title = `${fileCount} files only in old changeset`;
+                } else if (key === 'new 2') {
+                    title = `${fileCount} files only in new changeset`;
+                } else {
+                    title = `${fileCount} files changed`;
+                }
+            }
+
             // If there's more than one file in the rollup, list them
             if (rollup.files.length > 1) {
-                title += ` (${rollup.files.length - 1} more)`;
                 outString += '\n';
                 for (const file of rollup.files) {
                     outString += `- ${file}\n`;
                 }
+
+                // Simple replacement of the last filename with additional info
+                if (rollup.string.includes('```diff')) {
+                    const lastFileName = rollup.files[rollup.files.length - 1];
+                    const modifiedDiff = rollup.string.replace(
+                        `--- ${lastFileName}`,
+                        `--- ${lastFileName} (and ${rollup.files.length - 1} other files)`,
+                    );
+                    outString += '\n\n' + modifiedDiff;
+                } else {
+                    outString += '\n\n' + rollup.string;
+                }
+            } else {
+                outString += '\n\n' + rollup.string;
             }
-            outString += '\n\n' + rollup.string;
+
             return renderDetails(title, outString, isOpen);
         })
         .join('\n');
@@ -178,6 +208,6 @@ for (const [
     files,
 ] of Object.entries(sections)) {
     const isOpen = section === 'latest';
-    const fileOut = displayDiffs(files.dir1, files.dir2, isOpen);
+    const fileOut = displayDiffs(files.dir1 || {}, files.dir2 || {}, isOpen);
     console.log(renderDetails(section, fileOut, isOpen));
 }

.github/workflows/auto-respond-pr.yml

@@ -1,3 +1,16 @@
+# Auto Respond to PR Workflow
+#
+# This workflow automatically generates and posts diff comments showing changes to generated configuration files.
+#
+# ## Generated Diff Output Guide:
+# - **X files changed**: Multiple files with identical changes (collapsed for readability)
+# - **X files identical**: Files that are exactly the same between base and PR branches
+# - **File headers**: Show `--- filename (and X other files)` when multiple files share the same diff
+# - **File lists**: Individual files are listed under each collapsed section
+# - **Sections**: `latest` (current config version, expanded) and `legacy` (older versions, collapsed)
+#
+# The diff script groups files by their actual changes to reduce noise and improve review efficiency.
+
 name: Auto Respond to PR
 
 on:
@@ -95,7 +108,7 @@ jobs:
                       const prNumber = context.issue.number;
                       const diffOutput = fs.readFileSync('diff_output.txt', 'utf8');
                       let commentBody = `
-                      ### Generated file outputs:
+                      ### [Generated file outputs](https://github.com/duckduckgo/privacy-configuration/blob/main/.github/workflows/auto-respond-pr.yml#L5-L12):
                       *Time updated:* ${new Date().toUTCString()}
                       ${diffOutput}
                       `