ci: Post file stats on PRs (#32053)

.github/scripts/github-helpers.mjs

@@ -407,6 +407,60 @@ export async function getChangedFiles(pullRequestNumber) {
 	]);
 }
 
+/**
+ * Returns all files changed in a PR with full metadata including line counts.
+ *
+ * @param { number } pullRequestNumber
+ * @returns { Promise<Array<{ filename: string, additions: number, deletions: number, previous_filename?: string }>> }
+ * */
+export async function getPrFiles(pullRequestNumber) {
+	const { octokit, owner, repo } = initGithub();
+
+	return await octokit.paginate(octokit.rest.pulls.listFiles, {
+		owner,
+		repo,
+		pull_number: pullRequestNumber,
+		per_page: 100,
+	});
+}
+
+/**
+ * Post a PR comment, or update the existing one if a previous run already
+ * left one identified by the provided bot marker.
+ *
+ * @param { number } pullRequestNumber
+ * @param { string } body
+ * @param { string } botMarker
+ */
+export async function postOrUpdateComment(pullRequestNumber, body, botMarker) {
+	const { octokit, owner, repo } = initGithub();
+
+	const comments = await octokit.paginate(octokit.rest.issues.listComments, {
+		owner,
+		repo,
+		issue_number: pullRequestNumber,
+		per_page: 100,
+	});
+
+	const existing = comments.find((c) => c.body?.includes(botMarker));
+
+	if (existing) {
+		await octokit.rest.issues.updateComment({
+			owner,
+			repo,
+			comment_id: existing.id,
+			body,
+		});
+	} else {
+		await octokit.rest.issues.createComment({
+			owner,
+			repo,
+			issue_number: pullRequestNumber,
+			body,
+		});
+	}
+}
+
 /**
  * @param {string} tag
  */

.github/scripts/github-helpers.test.mjs

@@ -0,0 +1,90 @@
+import { afterEach, beforeEach, describe, it, mock } from 'node:test';
+import assert from 'node:assert/strict';
+
+/**
+ * Run these tests by running
+ *
+ * node --test --experimental-test-module-mocks ./.github/scripts/github-helpers.test.mjs
+ * */
+
+let octokitImpl;
+
+mock.module('@actions/github', {
+	namedExports: {
+		getOctokit: () => octokitImpl(),
+	},
+});
+
+const { postOrUpdateComment } = await import('./github-helpers.mjs');
+
+const ORIGINAL_ENV = { ...process.env };
+
+describe('postOrUpdateComment', () => {
+	beforeEach(() => {
+		process.env.GITHUB_TOKEN = 'token';
+		process.env.GITHUB_REPOSITORY = 'n8n-io/n8n';
+	});
+
+	afterEach(() => {
+		process.env = { ...ORIGINAL_ENV };
+	});
+
+	it('creates a new comment when no existing bot-marker comment is found', async () => {
+		const createComment = mock.fn(async () => {});
+		const updateComment = mock.fn(async () => {});
+		const paginate = mock.fn(async () => [{ id: 1, body: 'unrelated comment' }]);
+		octokitImpl = () => ({
+			paginate,
+			rest: {
+				issues: {
+					listComments: {},
+					createComment,
+					updateComment,
+				},
+			},
+		});
+
+		await postOrUpdateComment(123, 'new body', '<!-- marker -->');
+
+		assert.equal(updateComment.mock.calls.length, 0);
+		assert.equal(createComment.mock.calls.length, 1);
+		assert.deepEqual(createComment.mock.calls[0].arguments[0], {
+			owner: 'n8n-io',
+			repo: 'n8n',
+			issue_number: 123,
+			body: 'new body',
+		});
+		assert.deepEqual(paginate.mock.calls[0].arguments[1], {
+			owner: 'n8n-io',
+			repo: 'n8n',
+			issue_number: 123,
+			per_page: 100,
+		});
+	});
+
+	it('updates the existing comment when a bot-marker comment is found', async () => {
+		const createComment = mock.fn(async () => {});
+		const updateComment = mock.fn(async () => {});
+		octokitImpl = () => ({
+			paginate: mock.fn(async () => [{ id: 42, body: '<!-- marker -->\nold body' }]),
+			rest: {
+				issues: {
+					listComments: {},
+					createComment,
+					updateComment,
+				},
+			},
+		});
+
+		await postOrUpdateComment(123, 'updated body', '<!-- marker -->');
+
+		assert.equal(createComment.mock.calls.length, 0);
+		assert.equal(updateComment.mock.calls.length, 1);
+		assert.deepEqual(updateComment.mock.calls[0].arguments[0], {
+			owner: 'n8n-io',
+			repo: 'n8n',
+			comment_id: 42,
+			body: 'updated body',
+		});
+	});
+});

.github/scripts/owners-review-recommendations.mjs

@@ -1,104 +1,254 @@
-import { ensureEnvVar, getChangedFiles, initGithub } from "./github-helpers.mjs";
-import { assignOwnership, ownershipsToAllocations, parseOwnersFile } from "./owners.mjs";
+/**
+ * PR recommendations entry point.
+ *
+ * Posts (or updates) a single PR comment that combines:
+ *   - Recommended reviewer teams based on file ownership
+ *   - A breakdown of changed lines by category (source code, test files, misc)
+ *
+ * Advisory only — does not gate merging.
+ */
+
+import { minimatch } from 'minimatch';
+import { ensureEnvVar, getPrFiles, postOrUpdateComment } from './github-helpers.mjs';
+import { assignOwnership, ownershipsToAllocations, parseOwnersFile } from './owners.mjs';
+import { MISC_PATTERNS, SIZE_LIMIT, TEST_PATTERNS } from './quality/check-pr-size.mjs';
 
 /** @typedef {import('./owners.mjs').Allocation} Allocation */
 
 /**
- * @param { number } pullRequestNumber
- * */
-export async function getReviewRecommendations(pullRequestNumber) {
-	const changedFiles = await getChangedFiles(pullRequestNumber);
-	const owners = parseOwnersFile();
+ * @typedef {{
+ *   sourceCodeAdded: number, sourceCodeRemoved: number,
+ *   testFilesAdded: number, testFilesRemoved: number,
+ *   miscAdded: number, miscRemoved: number,
+ * }} LineStats
+ */
 
-	const ownerships = assignOwnership(changedFiles, owners);
-	const allocations = ownershipsToAllocations(ownerships);
+const BOT_MARKER = '<!-- pr-recommendations -->';
 
-	const topAllocations = allocations.sort((a, b) => b.fileCount - a.fileCount).slice(0, 3);
-
-	await commentOnPrWithRecommendations(pullRequestNumber, topAllocations, changedFiles);
+function createEmptyLineStats() {
+	return {
+		sourceCodeAdded: 0,
+		sourceCodeRemoved: 0,
+		testFilesAdded: 0,
+		testFilesRemoved: 0,
+		miscAdded: 0,
+		miscRemoved: 0,
+	};
 }
 
-const BOT_MARKER = "<!-- owners-review-recommendations -->";
+/**
+ * @param { LineStats } stats
+ * @param {{ filename: string, additions: number, deletions: number }} file
+ */
+function addFileToLineStats(stats, file) {
+	const isTest = TEST_PATTERNS.some((p) => minimatch(file.filename, p));
+	const isMisc = !isTest && MISC_PATTERNS.some((p) => minimatch(file.filename, p));
+
+	if (isTest) {
+		stats.testFilesAdded += file.additions;
+		stats.testFilesRemoved += file.deletions;
+	} else if (isMisc) {
+		stats.miscAdded += file.additions;
+		stats.miscRemoved += file.deletions;
+	} else {
+		stats.sourceCodeAdded += file.additions;
+		stats.sourceCodeRemoved += file.deletions;
+	}
+}
 
 /**
- * Build the PR comment body listing the top reviewer teams with their share
- * of ownership over the changed files.
+ * Compute line addition and deletion counts categorised as source code,
+ * test files, or misc.
+ *
+ * @param { Array<{ filename: string, additions: number, deletions: number }> } files
+ * @returns { LineStats }
+ */
+export function computeLineStats(files) {
+	const stats = createEmptyLineStats();
+
+	for (const file of files) {
+		addFileToLineStats(stats, file);
+	}
+
+	return stats;
+}
+
+/**
+ * Compute line stats for each owner allocation. Renamed files can be owned by
+ * either their previous or current filename, but are counted only once per team.
+ *
+ * @param { Allocation[] } allocations
+ * @param { Map<string, string[]> } ownerships
+ * @param { Array<{ filename: string, previous_filename?: string, additions: number, deletions: number }> } files
+ * @returns { Map<string, LineStats> }
+ */
+export function computeAllocationLineStats(allocations, ownerships, files) {
+	const statsByTeam = new Map();
+
+	for (const { team } of allocations) {
+		const stats = createEmptyLineStats();
+		const ownedFiles = new Set(ownerships.get(team) ?? []);
+
+		for (const file of files) {
+			if (ownedFiles.has(file.filename) || ownedFiles.has(file.previous_filename)) {
+				addFileToLineStats(stats, file);
+			}
+		}
+
+		statsByTeam.set(team, stats);
+	}
+
+	return statsByTeam;
+}
+
+/**
+ * @param { LineStats } lineStats
+ * @param {'sourceCode' | 'testFiles' | 'misc'} key
+ * @returns { string }
+ */
+function formatLineStatsCell(lineStats, key) {
+	return `+${lineStats[`${key}Added`].toLocaleString()} / -${lineStats[`${key}Removed`].toLocaleString()}`;
+}
+
+/**
+ * @param { LineStats } lineStats
+ * @returns { number }
+ */
+function totalLineChanges(lineStats) {
+	return (
+		lineStats.sourceCodeAdded +
+		lineStats.sourceCodeRemoved +
+		lineStats.testFilesAdded +
+		lineStats.testFilesRemoved +
+		lineStats.miscAdded +
+		lineStats.miscRemoved
+	);
+}
+
+/**
+ * @param { LineStats } target
+ * @param { LineStats } source
+ */
+function addLineStats(target, source) {
+	target.sourceCodeAdded += source.sourceCodeAdded;
+	target.sourceCodeRemoved += source.sourceCodeRemoved;
+	target.testFilesAdded += source.testFilesAdded;
+	target.testFilesRemoved += source.testFilesRemoved;
+	target.miscAdded += source.miscAdded;
+	target.miscRemoved += source.miscRemoved;
+}
+
+/**
+ * @param { Allocation[] } allocations
+ * @param { Map<string, LineStats> } lineStatsByTeam
+ * @returns { LineStats }
+ */
+function aggregateLineStats(allocations, lineStatsByTeam) {
+	const stats = createEmptyLineStats();
+
+	for (const { team } of allocations) {
+		addLineStats(stats, lineStatsByTeam.get(team) ?? createEmptyLineStats());
+	}
+
+	return stats;
+}
+
+/**
+ * Build an ownership-first overview table with line stats grouped by team.
  *
  * @param { Allocation[] } allocations
  * @param { Set<string> } changedFiles
+ * @param { LineStats } totalLineStats
+ * @param { Map<string, LineStats> } lineStatsByTeam
+ * @param { Allocation[] } [otherAllocations]
  * @returns { string }
- * */
-export function buildRecommendationsBody(allocations, changedFiles) {
+ */
+export function buildOverviewTable(allocations, changedFiles, totalLineStats, lineStatsByTeam, otherAllocations = []) {
 	const total = changedFiles.size;
+	const rows = allocations.length > 0 && total > 0
+		? allocations.map(({ team, fileCount }) => {
+			const pct = Math.round((fileCount / total) * 100);
+			const teamLineStats = lineStatsByTeam.get(team) ?? createEmptyLineStats();
+			return `| ${team} | ${fileCount} | ${pct}% | ${formatLineStatsCell(teamLineStats, 'sourceCode')} | ${formatLineStatsCell(teamLineStats, 'testFiles')} | ${formatLineStatsCell(teamLineStats, 'misc')} |`;
+		})
+		: [`| _No owning teams matched_ | 0 | 0% | ${formatLineStatsCell(totalLineStats, 'sourceCode')} | ${formatLineStatsCell(totalLineStats, 'testFiles')} | ${formatLineStatsCell(totalLineStats, 'misc')} |`];
 
-	if (allocations.length === 0 || total === 0) {
-		return [
-			BOT_MARKER,
-			"## Recommended reviewers",
-			"",
-			"_No owning teams matched the files changed in this PR._",
-		].join("\n");
+	if (otherAllocations.length > 0 && total > 0) {
+		const otherFileCount = otherAllocations.reduce((sum, { fileCount }) => sum + fileCount, 0);
+		const otherPct = Math.round((otherFileCount / total) * 100);
+		const otherLineStats = aggregateLineStats(otherAllocations, lineStatsByTeam);
+		rows.push(`| Other teams | ${otherFileCount} | ${otherPct}% | ${formatLineStatsCell(otherLineStats, 'sourceCode')} | ${formatLineStatsCell(otherLineStats, 'testFiles')} | ${formatLineStatsCell(otherLineStats, 'misc')} |`);
 	}
 
-	const rows = allocations.map(({ team, fileCount }) => {
-		const pct = Math.round((fileCount / total) * 100);
-		return `| ${team} | ${fileCount} | ${pct}% |`;
-	});
-
 	return [
-		BOT_MARKER,
-		"## Recommended reviewers",
-		"",
-		`Based on ownership of the ${total} changed file${total === 1 ? "" : "s"} in this PR:`,
-		"",
-		"| Team | Files owned | Share |",
-		"| --- | ---: | ---: |",
+		'## PR review overview',
+		'',
+		`Based on ownership of the ${total} changed file${total === 1 ? '' : 's'} in this PR:`,
+		'',
+		'| Ownership | Files owned | Share | Source code | Test files | Misc |',
+		'| --- | ---: | ---: | ---: | ---: | ---: |',
 		...rows,
-	].join("\n");
+		`| **Total** | **${total.toLocaleString()}** | **${total === 0 ? 0 : 100}%** | **${formatLineStatsCell(totalLineStats, 'sourceCode')}** | **${formatLineStatsCell(totalLineStats, 'testFiles')}** | **${formatLineStatsCell(totalLineStats, 'misc')}** |`,
+	].join('\n');
 }
 
 /**
- * Post the recommendations as a PR comment, or update the existing one if a
- * previous run already left one (identified by BOT_MARKER).
+ * Construct the full PR comment body from reviewer allocations and line stats.
  *
- * @param { number } pullRequestNumber
  * @param { Allocation[] } allocations
  * @param { Set<string> } changedFiles
- * */
-export async function commentOnPrWithRecommendations(pullRequestNumber, allocations, changedFiles) {
-	const { octokit, owner, repo } = initGithub();
+ * @param { LineStats } lineStats
+ * @param { Map<string, LineStats> } lineStatsByTeam
+ * @param { Allocation[] } [otherAllocations]
+ * @returns { string }
+ */
+export function buildComment(allocations, changedFiles, lineStats, lineStatsByTeam = new Map(), otherAllocations = []) {
+	const body = [
+		BOT_MARKER,
+		buildOverviewTable(allocations, changedFiles, lineStats, lineStatsByTeam, otherAllocations),
+	];
 
-	const body = buildRecommendationsBody(allocations, changedFiles);
-
-	const comments = await octokit.paginate(octokit.rest.issues.listComments, {
-		owner,
-		repo,
-		issue_number: pullRequestNumber,
-		per_page: 100,
-	});
-
-	const existing = comments.find(c => c.body?.includes(BOT_MARKER));
-
-	if (existing) {
-		await octokit.rest.issues.updateComment({
-			owner,
-			repo,
-			comment_id: existing.id,
-			body,
-		});
-	} else {
-		await octokit.rest.issues.createComment({
-			owner,
-			repo,
-			issue_number: pullRequestNumber,
-			body,
-		});
+	if (lineStats.sourceCodeAdded > SIZE_LIMIT) {
+		body.push('', `❗ Source code additions (${lineStats.sourceCodeAdded.toLocaleString()}) exceed the ${SIZE_LIMIT.toLocaleString()}-line limit.`);
 	}
+
+	return body.join('\n');
+}
+
+/**
+ * @param { number } pullRequestNumber
+ */
+export async function run(pullRequestNumber) {
+	const files = await getPrFiles(pullRequestNumber);
+
+	const changedFiles = new Set([
+		...files.map((f) => f.filename),
+		...files.filter((f) => f.previous_filename).map((f) => f.previous_filename),
+	]);
+
+	const lineStats = computeLineStats(files);
+
+	const owners = parseOwnersFile();
+	const ownerships = assignOwnership(changedFiles, owners);
+	const allocations = ownershipsToAllocations(ownerships);
+	const lineStatsByTeam = computeAllocationLineStats(allocations, ownerships, files);
+	const sortedAllocations = allocations
+		.toSorted((a, b) => {
+			const lineChangeDiff =
+				totalLineChanges(lineStatsByTeam.get(b.team) ?? createEmptyLineStats()) -
+				totalLineChanges(lineStatsByTeam.get(a.team) ?? createEmptyLineStats());
+
+			return lineChangeDiff || b.fileCount - a.fileCount;
+		});
+	const topAllocations = sortedAllocations.slice(0, 3);
+	const otherAllocations = sortedAllocations.slice(3);
+
+	const body = buildComment(topAllocations, changedFiles, lineStats, lineStatsByTeam, otherAllocations);
+
+	await postOrUpdateComment(pullRequestNumber, body, BOT_MARKER);
 }
 
-// only run when executed directly, not when imported by tests
 if (import.meta.url === `file://${process.argv[1]}`) {
-	const pullRequestNumber = parseInt(ensureEnvVar("PULL_REQUEST_NUMBER"));
-
-	await getReviewRecommendations(pullRequestNumber);
+	const pullRequestNumber = parseInt(ensureEnvVar('PULL_REQUEST_NUMBER'));
+	await run(pullRequestNumber);
 }

.github/scripts/owners-review-recommendations.test.mjs

@@ -1,4 +1,4 @@
-import { describe, it, mock } from 'node:test';
+import { beforeEach, describe, it, mock } from 'node:test';
 import assert from 'node:assert/strict';
 
 /**
@@ -7,71 +7,382 @@ import assert from 'node:assert/strict';
  * node --test --experimental-test-module-mocks ./.github/scripts/owners-review-recommendations.test.mjs
  * */
 
-// mock.module must be called before the module under test is imported,
-// because static imports are hoisted and resolve before any code runs.
+/** @type {(pullRequestNumber: number) => Promise<Array<{ filename: string, additions: number, deletions: number, previous_filename?: string }>>} */
+let getPrFilesImpl = async () => [];
+/** @type {(pullRequestNumber: number, body: string, botMarker: string) => Promise<void>} */
+let postOrUpdateCommentImpl = async () => {};
+
 mock.module('./github-helpers.mjs', {
 	namedExports: {
 		ensureEnvVar: () => {}, // no-op in tests
 		initGithub: () => {}, // no-op in tests
-		getChangedFiles: () => Promise.resolve(new Set()), // no-op in tests
+		getChangedFiles: () => Promise.resolve(new Set()),
+		getEventFromGithubEventPath: () => ({}),
+		getPrFiles: (n) => getPrFilesImpl(n),
+		postOrUpdateComment: (pullRequestNumber, body, botMarker) =>
+			postOrUpdateCommentImpl(pullRequestNumber, body, botMarker),
 	},
 });
 
-/** @type { (allocations: { team: string, fileCount: number }[], changedFiles: Set<string>) => string } */
-let buildRecommendationsBody;
-const { buildRecommendationsBody: imported } = await import('./owners-review-recommendations.mjs');
-buildRecommendationsBody = imported;
+/** @type {() => Array<{ filepath: string, team: string }>} */
+let parseOwnersFileImpl = () => [];
+/** @type {(files: Set<string>, owners: Array<{ filepath: string, team: string }>) => Map<string, string[]>} */
+let assignOwnershipImpl = () => new Map();
+/** @type {(ownerships: Map<string, string[]>) => Array<{ team: string, fileCount: number }>} */
+let ownershipsToAllocationsImpl = () => [];
 
-describe('buildRecommendationsBody', () => {
-	const marker = '<!-- owners-review-recommendations -->';
+mock.module('./owners.mjs', {
+	namedExports: {
+		parseOwnersFile: () => parseOwnersFileImpl(),
+		assignOwnership: (files, owners) => assignOwnershipImpl(files, owners),
+		ownershipsToAllocations: (ownerships) => ownershipsToAllocationsImpl(ownerships),
+	},
+});
 
-	it('returns the fallback message when there are no allocations', () => {
-		const body = buildRecommendationsBody([], new Set(['a.ts']));
+const { buildOverviewTable, buildComment, computeAllocationLineStats, computeLineStats, run } =
+	await import('./owners-review-recommendations.mjs');
 
-		assert.ok(body.startsWith(marker), 'body must start with the bot marker');
-		assert.match(body, /No owning teams matched/);
-	});
+const BOT_MARKER = '<!-- pr-recommendations -->';
+const EMPTY_LINE_STATS = {
+	sourceCodeAdded: 0,
+	sourceCodeRemoved: 0,
+	testFilesAdded: 0,
+	testFilesRemoved: 0,
+	miscAdded: 0,
+	miscRemoved: 0,
+};
 
-	it('returns the fallback message when no files changed', () => {
-		const body = buildRecommendationsBody(
-			[{ team: '@n8n-io/cli-team', fileCount: 0 }],
-			new Set(),
-		);
-
-		assert.match(body, /No owning teams matched/);
-	});
-
-	it('renders a table with team name, file count, and rounded percentage', () => {
-		const body = buildRecommendationsBody(
+describe('buildOverviewTable', () => {
+	it('renders an ownership-first table with per-team line stats', () => {
+		const table = buildOverviewTable(
 			[
-				{ team: '@n8n-io/cli-team', fileCount: 6 },
-				{ team: '@n8n-io/catalysts', fileCount: 3 },
-				{ team: '@n8n-io/ai-team', fileCount: 1 },
+				{ team: '@n8n-io/cli-team', fileCount: 2 },
+				{ team: '@n8n-io/editor-ui-team', fileCount: 1 },
 			],
-			new Set(['1', '2', '3', '4', '5', '6', '7', '8', '9', '10']),
+			new Set(['a.ts', 'b.test.ts', 'README.md']),
+			{
+				sourceCodeAdded: 10,
+				sourceCodeRemoved: 2,
+				testFilesAdded: 5,
+				testFilesRemoved: 1,
+				miscAdded: 3,
+				miscRemoved: 0,
+			},
+			new Map([
+				[
+					'@n8n-io/cli-team',
+					{
+						sourceCodeAdded: 10,
+						sourceCodeRemoved: 2,
+						testFilesAdded: 5,
+						testFilesRemoved: 1,
+						miscAdded: 0,
+						miscRemoved: 0,
+					},
+				],
+				[
+					'@n8n-io/editor-ui-team',
+					{
+						sourceCodeAdded: 0,
+						sourceCodeRemoved: 0,
+						testFilesAdded: 0,
+						testFilesRemoved: 0,
+						miscAdded: 3,
+						miscRemoved: 0,
+					},
+				],
+			]),
 		);
 
-		assert.ok(body.startsWith(marker));
-		assert.match(body, /\| @n8n-io\/cli-team \| 6 \| 60% \|/);
-		assert.match(body, /\| @n8n-io\/catalysts \| 3 \| 30% \|/);
-		assert.match(body, /\| @n8n-io\/ai-team \| 1 \| 10% \|/);
+		assert.match(table, /## PR review overview/);
+		assert.match(table, /\| Ownership \| Files owned \| Share \| Source code \| Test files \| Misc \|/);
+		assert.match(table, /\| @n8n-io\/cli-team \| 2 \| 67% \| \+10 \/ -2 \| \+5 \/ -1 \| \+0 \/ -0 \|/);
+		assert.match(table, /\| @n8n-io\/editor-ui-team \| 1 \| 33% \| \+0 \/ -0 \| \+0 \/ -0 \| \+3 \/ -0 \|/);
+		assert.match(table, /\| \*\*Total\*\* \| \*\*3\*\* \| \*\*100%\*\* \| \*\*\+10 \/ -2\*\* \| \*\*\+5 \/ -1\*\* \| \*\*\+3 \/ -0\*\* \|/);
+	});
+
+	it('renders a no-owner row when no owners matched', () => {
+		const table = buildOverviewTable(
+			[],
+			new Set(['a.ts']),
+			{ ...EMPTY_LINE_STATS, sourceCodeAdded: 12, sourceCodeRemoved: 1 },
+			new Map(),
+		);
+
+		assert.match(table, /\| _No owning teams matched_ \| 0 \| 0% \| \+12 \/ -1 \| \+0 \/ -0 \| \+0 \/ -0 \|/);
 	});
 
 	it('uses singular "file" when exactly one file changed', () => {
-		const body = buildRecommendationsBody(
+		const table = buildOverviewTable(
 			[{ team: '@n8n-io/cli-team', fileCount: 1 }],
 			new Set(['only.ts']),
+			EMPTY_LINE_STATS,
+			new Map(),
 		);
 
-		assert.match(body, /ownership of the 1 changed file in this PR/);
+		assert.match(table, /ownership of the 1 changed file in this PR/);
 	});
 
-	it('uses plural "files" for more than one changed file', () => {
-		const body = buildRecommendationsBody(
-			[{ team: '@n8n-io/cli-team', fileCount: 2 }],
+	it('uses plural "files" for more than one file changed', () => {
+		const table = buildOverviewTable(
+			[{ team: '@n8n-io/cli-team', fileCount: 1 }],
 			new Set(['a.ts', 'b.ts']),
+			EMPTY_LINE_STATS,
+			new Map(),
 		);
 
-		assert.match(body, /ownership of the 2 changed files in this PR/);
+		assert.match(table, /ownership of the 2 changed files in this PR/);
+	});
+
+	it('renders an aggregate row for allocations outside the displayed teams', () => {
+		const table = buildOverviewTable(
+			[{ team: '@n8n-io/cli-team', fileCount: 2 }],
+			new Set(['a.ts', 'b.ts', 'c.ts']),
+			{ ...EMPTY_LINE_STATS, sourceCodeAdded: 13, sourceCodeRemoved: 3 },
+			new Map([
+				['@n8n-io/cli-team', { ...EMPTY_LINE_STATS, sourceCodeAdded: 10, sourceCodeRemoved: 1 }],
+				['@n8n-io/team-a', { ...EMPTY_LINE_STATS, sourceCodeAdded: 2, sourceCodeRemoved: 1 }],
+				['@n8n-io/team-b', { ...EMPTY_LINE_STATS, sourceCodeAdded: 1, sourceCodeRemoved: 1 }],
+			]),
+			[
+				{ team: '@n8n-io/team-a', fileCount: 1 },
+				{ team: '@n8n-io/team-b', fileCount: 1 },
+			],
+		);
+
+		assert.match(table, /\| Other teams \| 2 \| 67% \| \+3 \/ -2 \| \+0 \/ -0 \| \+0 \/ -0 \|/);
+	});
+});
+
+describe('buildComment', () => {
+	it('starts with the bot marker', () => {
+		const body = buildComment([], new Set(['a.ts']), EMPTY_LINE_STATS);
+
+		assert.ok(body.startsWith(BOT_MARKER), 'body must start with the bot marker');
+	});
+
+	it('includes the overview table', () => {
+		const body = buildComment(
+			[{ team: '@n8n-io/cli-team', fileCount: 1 }],
+			new Set(['a.ts']),
+			{ ...EMPTY_LINE_STATS, sourceCodeAdded: 42 },
+		);
+
+		assert.match(body, /## PR review overview/);
+		assert.match(body, /\| @n8n-io\/cli-team \| 1 \| 100% \|/);
+	});
+
+	it('shows a warning below the table when source code additions exceed the size limit', () => {
+		const body = buildComment([], new Set(['a.ts']), { ...EMPTY_LINE_STATS, sourceCodeAdded: 1001 });
+
+		assert.match(body, /❗ Source code additions \(1[,.]001\) exceed the 1[,.]000-line limit\./);
+	});
+});
+
+describe('computeLineStats', () => {
+	it('returns all zeros for an empty file list', () => {
+		assert.deepEqual(computeLineStats([]), EMPTY_LINE_STATS);
+	});
+
+	it('categorises a plain source file as source code', () => {
+		const stats = computeLineStats([{ filename: 'src/foo.ts', additions: 10, deletions: 3 }]);
+
+		assert.equal(stats.sourceCodeAdded, 10);
+		assert.equal(stats.sourceCodeRemoved, 3);
+		assert.equal(stats.testFilesAdded, 0);
+		assert.equal(stats.miscAdded, 0);
+	});
+
+	describe('test file patterns', () => {
+		for (const [label, filename] of [
+			['*.test.ts', 'src/foo.test.ts'],
+			['*.test.js', 'src/foo.test.js'],
+			['*.test.mjs', 'src/foo.test.mjs'],
+			['*.spec.ts', 'src/foo.spec.ts'],
+			['*.spec.js', 'src/foo.spec.js'],
+			['*.spec.mjs', 'src/foo.spec.mjs'],
+			['test/ directory', 'packages/cli/test/helpers.ts'],
+			['tests/ directory', 'packages/cli/tests/helpers.ts'],
+			['__tests__/ directory', 'src/__tests__/foo.ts'],
+			['__snapshots__/ directory', 'src/__snapshots__/foo.snap'],
+			['*.snap extension', 'src/foo.snap'],
+			['fixtures/ directory', 'src/fixtures/data.json'],
+			['__mocks__/ directory', 'src/__mocks__/axios.ts'],
+			['packages/testing/**', 'packages/testing/playwright/spec.ts'],
+		]) {
+			it(`classifies ${label} as testFiles`, () => {
+				const stats = computeLineStats([{ filename, additions: 7, deletions: 2 }]);
+
+				assert.equal(stats.testFilesAdded, 7, `expected ${filename} to be a test file`);
+				assert.equal(stats.testFilesRemoved, 2);
+				assert.equal(stats.sourceCodeAdded, 0);
+				assert.equal(stats.miscAdded, 0);
+			});
+		}
+	});
+
+	describe('misc file patterns', () => {
+		for (const [label, filename] of [
+			['pnpm-lock.yaml', 'pnpm-lock.yaml'],
+			['*.md', 'README.md'],
+			['nested *.md', 'packages/cli/CHANGELOG.md'],
+			['*.mdx', 'docs/guide.mdx'],
+			['nested *.mdx', 'packages/editor-ui/docs/page.mdx'],
+		]) {
+			it(`classifies ${label} as misc`, () => {
+				const stats = computeLineStats([{ filename, additions: 3, deletions: 1 }]);
+
+				assert.equal(stats.miscAdded, 3, `expected ${filename} to be misc`);
+				assert.equal(stats.miscRemoved, 1);
+				assert.equal(stats.sourceCodeAdded, 0);
+				assert.equal(stats.testFilesAdded, 0);
+			});
+		}
+	});
+
+	it('sums additions and deletions across multiple files per category', () => {
+		const stats = computeLineStats([
+			{ filename: 'src/a.ts', additions: 10, deletions: 5 },
+			{ filename: 'src/b.ts', additions: 15, deletions: 3 },
+			{ filename: 'src/a.test.ts', additions: 5, deletions: 1 },
+			{ filename: 'src/b.spec.ts', additions: 8, deletions: 2 },
+			{ filename: 'pnpm-lock.yaml', additions: 100, deletions: 50 },
+			{ filename: 'README.md', additions: 20, deletions: 10 },
+		]);
+
+		assert.equal(stats.sourceCodeAdded, 25);
+		assert.equal(stats.sourceCodeRemoved, 8);
+		assert.equal(stats.testFilesAdded, 13);
+		assert.equal(stats.testFilesRemoved, 3);
+		assert.equal(stats.miscAdded, 120);
+		assert.equal(stats.miscRemoved, 60);
+	});
+});
+
+describe('computeAllocationLineStats', () => {
+	it('computes line stats per owner allocation', () => {
+		const statsByTeam = computeAllocationLineStats(
+			[
+				{ team: '@n8n-io/cli-team', fileCount: 2 },
+				{ team: '@n8n-io/docs-team', fileCount: 1 },
+			],
+			new Map([
+				['@n8n-io/cli-team', ['src/a.ts', 'src/a.test.ts']],
+				['@n8n-io/docs-team', ['README.md']],
+			]),
+			[
+				{ filename: 'src/a.ts', additions: 10, deletions: 1 },
+				{ filename: 'src/a.test.ts', additions: 5, deletions: 2 },
+				{ filename: 'README.md', additions: 3, deletions: 1 },
+			],
+		);
+
+		assert.deepEqual(statsByTeam.get('@n8n-io/cli-team'), {
+			sourceCodeAdded: 10,
+			sourceCodeRemoved: 1,
+			testFilesAdded: 5,
+			testFilesRemoved: 2,
+			miscAdded: 0,
+			miscRemoved: 0,
+		});
+		assert.deepEqual(statsByTeam.get('@n8n-io/docs-team'), {
+			sourceCodeAdded: 0,
+			sourceCodeRemoved: 0,
+			testFilesAdded: 0,
+			testFilesRemoved: 0,
+			miscAdded: 3,
+			miscRemoved: 1,
+		});
+	});
+
+	it('matches renamed files by previous filename', () => {
+		const statsByTeam = computeAllocationLineStats(
+			[{ team: '@n8n-io/cli-team', fileCount: 1 }],
+			new Map([['@n8n-io/cli-team', ['old-name.ts']]]),
+			[{ filename: 'new-name.ts', previous_filename: 'old-name.ts', additions: 7, deletions: 3 }],
+		);
+
+		assert.equal(statsByTeam.get('@n8n-io/cli-team').sourceCodeAdded, 7);
+		assert.equal(statsByTeam.get('@n8n-io/cli-team').sourceCodeRemoved, 3);
+	});
+});
+
+describe('run', () => {
+	let postOrUpdateComment;
+
+	beforeEach(() => {
+		getPrFilesImpl = async () => [];
+		postOrUpdateComment = mock.fn(async () => {});
+		postOrUpdateCommentImpl = postOrUpdateComment;
+		parseOwnersFileImpl = () => [];
+		assignOwnershipImpl = () => new Map();
+		ownershipsToAllocationsImpl = () => [];
+	});
+
+	it('calls postOrUpdateComment with the PR number, generated body, and bot marker', async () => {
+		await run(42);
+
+		assert.equal(postOrUpdateComment.mock.calls.length, 1, 'postOrUpdateComment should be called once');
+		assert.equal(postOrUpdateComment.mock.calls[0].arguments[0], 42);
+		assert.ok(postOrUpdateComment.mock.calls[0].arguments[1].includes(BOT_MARKER));
+		assert.equal(postOrUpdateComment.mock.calls[0].arguments[2], BOT_MARKER);
+	});
+
+	it('includes renamed files in the changed files set', async () => {
+		getPrFilesImpl = async () => [
+			{ filename: 'new-name.ts', additions: 5, deletions: 0, previous_filename: 'old-name.ts' },
+		];
+
+		let capturedChangedFiles = new Set();
+		assignOwnershipImpl = (files) => {
+			capturedChangedFiles = files;
+			return new Map();
+		};
+
+		await run(42);
+
+		assert.ok(capturedChangedFiles.has('new-name.ts'), 'new filename must be included');
+		assert.ok(capturedChangedFiles.has('old-name.ts'), 'previous filename must be included');
+	});
+
+	it('limits recommendations to the top 3 allocations by total line changes', async () => {
+		getPrFilesImpl = async () => [
+			{ filename: 'a.ts', additions: 1, deletions: 0 },
+			{ filename: 'b.ts', additions: 50, deletions: 50 },
+			{ filename: 'c.ts', additions: 20, deletions: 20 },
+			{ filename: 'd.ts', additions: 10, deletions: 10 },
+		];
+		assignOwnershipImpl = () =>
+			new Map([
+				['@n8n-io/team-a', ['a.ts']],
+				['@n8n-io/team-b', ['b.ts']],
+				['@n8n-io/team-c', ['c.ts']],
+				['@n8n-io/team-d', ['d.ts']],
+			]);
+		ownershipsToAllocationsImpl = () => [
+			{ team: '@n8n-io/team-a', fileCount: 1 },
+			{ team: '@n8n-io/team-b', fileCount: 1 },
+			{ team: '@n8n-io/team-c', fileCount: 1 },
+			{ team: '@n8n-io/team-d', fileCount: 1 },
+		];
+
+		await run(42);
+
+		const body = postOrUpdateComment.mock.calls[0].arguments[1];
+		assert.match(body, /@n8n-io\/team-b[\s\S]*@n8n-io\/team-c[\s\S]*@n8n-io\/team-d/);
+		assert.doesNotMatch(body, /@n8n-io\/team-a/);
+		assert.match(body, /\| Other teams \| 1 \| 25% \| \+1 \/ -0 \| \+0 \/ -0 \| \+0 \/ -0 \|/);
+	});
+
+	it('posted comment body includes the ownership-first overview table', async () => {
+		getPrFilesImpl = async () => [{ filename: 'src/foo.ts', additions: 50, deletions: 5 }];
+		ownershipsToAllocationsImpl = () => [{ team: '@n8n-io/cli-team', fileCount: 1 }];
+		assignOwnershipImpl = () => new Map([['@n8n-io/cli-team', ['src/foo.ts']]]);
+
+		await run(42);
+
+		const body = postOrUpdateComment.mock.calls[0].arguments[1];
+		assert.match(body, /## PR review overview/);
+		assert.match(body, /\| @n8n-io\/cli-team \| 1 \| 100% \| \+50 \/ -5 \|/);
 	});
 });

.github/scripts/quality/check-pr-size.mjs

@@ -18,7 +18,7 @@ import { initGithub, getEventFromGithubEventPath } from '../github-helpers.mjs';
 export const SIZE_LIMIT = 1000;
 export const OVERRIDE_COMMAND = '/size-limit-override';
 
-export const EXCLUDE_PATTERNS = [
+export const TEST_PATTERNS = [
 	// Test files (by extension)
 	'**/*.test.ts',
 	'**/*.test.js',
@@ -38,12 +38,17 @@ export const EXCLUDE_PATTERNS = [
 	'**/__mocks__/**',
 	// Dedicated testing package
 	'packages/testing/**',
+];
+
+export const MISC_PATTERNS = [
 	// Lock file (can produce massive diffs on dependency changes)
 	'pnpm-lock.yaml',
 	'**/*.md',
-	'**/*.mdx'
+	'**/*.mdx',
 ];
 
+export const EXCLUDE_PATTERNS = [...TEST_PATTERNS, ...MISC_PATTERNS];
+
 const BOT_MARKER = '<!-- pr-size-check -->';
 
 /**

.github/workflows/ci-owners-review-recommendations.yml

@@ -1,7 +1,8 @@
 name: 'CI: Owners Review Recommendations'
 
-# Posts (or updates) a PR comment recommending which @n8n-io teams should
-# review the PR, based on file ownership defined in .github/OWNERS.
+# Posts (or updates) a PR comment with recommended reviewer teams (based on
+# file ownership in .github/OWNERS) and a breakdown of changed lines by
+# category (source code, test files, misc).
 #
 # Advisory only — does not gate merging.