ci(danger): map root files into explicit scopes

Author: alandefreitas

util/danger/README.md

@@ -15,6 +15,7 @@ This directory contains the Danger.js rules and fixtures used in CI to add scope
 npm --prefix util/danger ci           # install dev deps (without touching the repo root)
 npm --prefix util/danger test         # run Vitest unit tests for rule logic
 npm --prefix util/danger run danger:local  # print the fixture report from util/danger/fixtures/sample-pr.json
+npm --prefix util/danger run danger:scope-map  # emit JSON mapping every tracked file to its Danger scope
 npm --prefix util/danger run danger:ci     # run Danger in CI mode (requires GitHub PR context)
 ```
 
@@ -31,7 +32,7 @@ npm --prefix util/danger run danger:ci     # run Danger in CI mode (requires Git
 
 - Scopes reflect the MrDocs tree: `source`, `tests`, `golden-tests`, `docs`, `ci`, `build`, `tooling`, `third-party`, `other`.
 - Conventional commit types allowed: `feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert`.
-- Non-test commit size warning triggers around 800 lines of churn (tests and golden fixtures ignored).
+- Non-test commit size notice triggers at 2000 lines of churn (tests and golden fixtures ignored) and is informational.
 
 ## Updating rules
 

util/danger/list-scopes.ts

@@ -0,0 +1,61 @@
+//
+// Licensed under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// Copyright (c) 2025 Alan de Freitas ([email protected])
+//
+// Official repository: https://github.com/cppalliance/mrdocs
+//
+/**
+ * Utility script to map every tracked file to the scope Danger uses.
+ * Useful for spotting files that fall into the "other" bucket.
+ *
+ * Usage:
+ *   npm --prefix util/danger run danger:scope-map > scope-map.json
+ */
+
+import { execSync } from "node:child_process";
+import path from "node:path";
+import { classifyScope, scopeDisplayOrder, type ScopeKey } from "./logic";
+
+function initBuckets(): Record<ScopeKey, string[]> {
+    const buckets = {} as Record<ScopeKey, string[]>;
+    for (const scope of scopeDisplayOrder) {
+        buckets[scope] = [];
+    }
+    return buckets;
+}
+
+function main(): void {
+    const repoRoot = path.resolve(__dirname, "../..");
+    const output: Record<ScopeKey, string[]> = initBuckets();
+
+    const files = execSync("git ls-files", { cwd: repoRoot })
+        .toString()
+        .split("\n")
+        .map((line) => line.trim())
+        .filter(Boolean);
+
+    for (const file of files) {
+        const scope = classifyScope(file);
+        // Keep ordering stable to make diffs easy to read.
+        output[scope].push(file);
+    }
+
+    for (const scope of scopeDisplayOrder) {
+        output[scope].sort();
+    }
+
+    const counts = Object.fromEntries(scopeDisplayOrder.map((scope) => [scope, output[scope].length]));
+
+    const result = {
+        counts,
+        files: output,
+    };
+
+    // Pretty-print so it can be inspected or diffed easily.
+    console.log(JSON.stringify(result, null, 2));
+}
+
+main();

util/danger/logic.test.ts

@@ -41,13 +41,19 @@ describe("summarizeScopes", () => {
             { filename: "src/test/file.cpp", additions: 5, deletions: 1 },
             { filename: "test-files/golden-tests/out.xml", additions: 100, deletions: 0 },
             { filename: "docs/index.adoc", additions: 4, deletions: 0 },
+            { filename: "SourceFileNames.cpp", additions: 1, deletions: 0 },
+            { filename: ".clang-format", additions: 0, deletions: 0 },
+            { filename: ".gitignore", additions: 0, deletions: 0 },
+            { filename: "LICENSE.txt", additions: 0, deletions: 0 },
         ]);
 
-        expect(report.totals.source.files).toBe(1);
+        expect(report.totals.source.files).toBe(2);
         expect(report.totals.tests.files).toBe(1);
         expect(report.totals["golden-tests"].files).toBe(1);
         expect(report.totals.docs.files).toBe(1);
-        expect(report.overall.files).toBe(4);
+        expect(report.totals.tooling.files).toBe(1);
+        expect(report.totals.ci.files).toBe(2);
+        expect(report.overall.files).toBe(8);
     });
 });
 

util/danger/logic.ts

@@ -10,7 +10,7 @@
 /**
  * Semantic areas of the repository used to group diff churn in reports and rules.
  */
-type ScopeKey =
+export type ScopeKey =
     | "golden-tests"
     | "tests"
     | "source"
@@ -185,10 +185,10 @@ const scopeRules: ScopeRule[] = [
     },
     {
         scope: "source",
-        patterns: [/^src\//i, /^include\//i, /^examples\//i, /^share\//i],
+        patterns: [/^src\//i, /^include\//i, /^examples\//i, /^share\//i, /^SourceFileNames\.cpp$/i],
     },
     { scope: "docs", patterns: [/^docs\//i, /^README\.adoc$/i, /^Doxyfile/i] },
-    { scope: "ci", patterns: [/^\.github\//, /^\.roadmap\//] },
+    { scope: "ci", patterns: [/^\.github\//, /^\.roadmap\//, /^\.gitignore$/i, /^\.gitattributes$/i, /^LICENSE\.txt$/i] },
     {
         scope: "build",
         patterns: [
@@ -203,6 +203,7 @@ const scopeRules: ScopeRule[] = [
         ],
     },
     { scope: "tooling", patterns: [/^tools\//i, /^util\/(?!danger\/)/i] },
+    { scope: "tooling", patterns: [/^\.clang-format$/i] },
     { scope: "ci", patterns: [/^util\/danger\//i, /^\.github\//, /^\.roadmap\//] },
     { scope: "third-party", patterns: [/^third-party\//i] },
 ];
@@ -221,7 +222,7 @@ function normalizePath(path: string): string {
  * @param path raw file path from GitHub.
  * @returns matched ScopeKey or "other" if no rules match.
  */
-function getScope(path: string): ScopeKey {
+export function classifyScope(path: string): ScopeKey {
     const normalized = normalizePath(path);
     for (const rule of scopeRules) {
         if (rule.patterns.some((pattern) => pattern.test(normalized))) {
@@ -311,7 +312,7 @@ export function summarizeScopes(files: FileChange[]): ScopeReport {
     const fileSummaries: FileSummary[] = [];
 
     for (const file of files) {
-        const scope = getScope(file.filename);
+        const scope = classifyScope(file.filename);
         totals[scope].files += 1;
         totals[scope].additions += file.additions || 0;
         totals[scope].deletions += file.deletions || 0;
@@ -453,7 +454,7 @@ export function commitSizeInfos(commits: CommitInfo[]): string[] {
 
         let churn = 0;
         for (const file of commit.files) {
-            const scope = getScope(file.filename);
+            const scope = classifyScope(file.filename);
             if (scope !== "source") {
                 continue;
             }

util/danger/package.json

@@ -6,11 +6,12 @@
   "engines": {
     "node": ">=18"
   },
-  "scripts": {
-    "test": "vitest run",
-    "danger:ci": "danger ci --dangerfile dangerfile.ts",
-    "danger:local": "ts-node --project tsconfig.json run-local.ts"
-  },
+    "scripts": {
+        "test": "vitest run",
+        "danger:ci": "danger ci --dangerfile dangerfile.ts",
+        "danger:local": "ts-node --project tsconfig.json run-local.ts",
+        "danger:scope-map": "ts-node --project tsconfig.json list-scopes.ts"
+    },
   "devDependencies": {
     "@types/node": "^20.14.2",
     "danger": "^12.3.1",