ci: run all tests with Babel 7 and Babel 8

Author: Stanzilla

.github/workflows/build.yml

@@ -15,16 +15,33 @@ env:
 jobs:
   tests:
     strategy:
+      fail-fast: false
       matrix:
+        babel: ["7", "8"]
         node: ["22.13.0", "24", "25", "26"]
         os: ["ubuntu"]
+        exclude:
+          # Babel 8 requires Node.js 22.18.0 or newer on the 22.x line.
+          - babel: "8"
+            node: "22.13.0"
         include:
+          - os: ubuntu
+            node: "22.18.0"
+            babel: "8"
           - os: macos
             node: "24"
+            babel: "7"
+          - os: macos
+            node: "24"
+            babel: "8"
+          - os: windows
+            node: "24"
+            babel: "7"
           - os: windows
             node: "24"
+            babel: "8"
 
-    name: Tests (Node.js v${{ matrix.node }}, ${{ matrix.os }})
+    name: Tests (Babel ${{ matrix.babel }}, Node.js v${{ matrix.node }}, ${{ matrix.os }})
     runs-on: ${{ matrix.os }}-latest
 
     steps:
@@ -43,21 +60,29 @@ jobs:
       - name: Install dependencies
         run: pnpm install --frozen-lockfile
 
+      # Compile against the declared Babel 7 types before testing each runtime.
+      - name: Build packages
+        run: pnpm build
+
+      - name: Install Babel 8 runtime
+        if: "${{ matrix.babel == '8' }}"
+        run: pnpm --filter react-docgen add --save-exact @babel/core@8.0.1 @babel/traverse@8.0.4 @babel/types@8.0.4
+
       - name: Unit tests with coverage
         if: "${{ matrix.node == env.NODE_VERSION }}"
-        run: pnpm test -- --coverage
+        run: pnpm --filter react-docgen --filter @react-docgen/cli --parallel --no-bail test --coverage
 
       - name: Unit tests
         if: "${{ matrix.node != env.NODE_VERSION }}"
-        run: pnpm test
+        run: pnpm --filter react-docgen --filter @react-docgen/cli --parallel --no-bail test
 
       - name: Upload coverage
         if: "${{ matrix.node == env.NODE_VERSION }}"
         continue-on-error: true
         uses: coverallsapp/github-action@8d6379e14d29928660c4ba802d8e85393440b329 # v2
         with:
           parallel: true
-          flag-name: test-${{ matrix.os }}
+          flag-name: test-babel-${{ matrix.babel }}-${{ matrix.os }}
 
   finish:
     needs: tests

CONTRIBUTING.md

@@ -14,6 +14,26 @@ We actively welcome your pull requests.
 4. Ensure the test suite passes.
 5. Make sure your code lints and typechecks.
 
+## Babel compatibility tests
+
+CI runs all library and CLI tests separately with Babel 7 and Babel 8.
+Both runs build with the declared Babel 7 dependencies first. The Babel 8
+run then replaces the runtime dependencies, including those used by CLI
+subprocesses. This checks runtime compatibility, not compilation with Babel 8 types.
+
+To reproduce the Babel 8 run in a clean checkout:
+
+```sh
+pnpm install --frozen-lockfile
+pnpm build
+pnpm --filter react-docgen add --save-exact @babel/core@8.0.1 @babel/traverse@8.0.4 @babel/types@8.0.4
+pnpm --filter react-docgen --filter @react-docgen/cli --parallel --no-bail test --coverage
+```
+
+The install command changes `packages/react-docgen/package.json` and
+`pnpm-lock.yaml`. After testing, restore those two files and run
+`pnpm install --frozen-lockfile` to return to Babel 7.
+
 ## Issues
 We use GitHub issues to track public bugs. Please ensure your description is
 clear and has sufficient instructions to be able to reproduce the issue.

packages/react-docgen/package.json

@@ -53,8 +53,5 @@
     "doctrine": "^3.0.0",
     "resolve": "^1.22.1",
     "strip-indent": "^4.0.0"
-  },
-  "devDependencies": {
-    "babel-core-8": "npm:@babel/core@8.0.1"
   }
 }

…eact-docgen/src/__tests__/babel8-test.ts …rc/__tests__/parserCompatibility-test.tspackages/react-docgen/src/__tests__/babel8-test.ts renamed to packages/react-docgen/src/__tests__/parserCompatibility-test.ts packages/react-docgen/src/__tests__/babel8-test.ts renamed to packages/react-docgen/src/__tests__/parserCompatibility-test.ts

@@ -1,15 +1,13 @@
 import { parse } from '../main.js';
-import { expect, test, vi } from 'vitest';
+import { expect, test } from 'vitest';
 
-vi.mock('@babel/core', () => import('babel-core-8'));
-
-test('parses components with Babel 8', () => {
+test('parses components', () => {
   const result = parse('export function Button() { return <button />; }');
 
   expect(result).toHaveLength(1);
 });
 
-test('parses TypeScript function props with Babel 8', () => {
+test('parses TypeScript function props', () => {
   const result = parse(
     `export type MenuProps = {
       onOpenChange?: (open: boolean) => void;
@@ -37,7 +35,7 @@ test('parses TypeScript function props with Babel 8', () => {
   });
 });
 
-test('parses generic arrow functions in TypeScript files with Babel 8', () => {
+test('parses generic arrow functions in TypeScript files', () => {
   const result = parse(
     `import React from 'react';
 
@@ -54,7 +52,7 @@ test('parses generic arrow functions in TypeScript files with Babel 8', () => {
   expect(result).toHaveLength(1);
 });
 
-test('parses mapped TypeScript props with Babel 8', () => {
+test('parses mapped TypeScript props', () => {
   const result = parse(
     `export type StatusFiltersProps<K extends string = string> = {
       statuses?: { readonly [Key in K]: number };