chore(scripts): update license check to be more flexible @W-19066903

.git2gus/config.json

@@ -1,5 +1,5 @@
 {
     "productTag": "a1aB0000000g309IAA",
-    "defaultBuild": "256",
+    "defaultBuild": "258",
     "hideWorkItemUrl": true
 }

.github/workflows/unit.yml

@@ -51,7 +51,7 @@ jobs:
             - name: Check package.json integrity
               run: node ./scripts/tasks/check-and-rewrite-package-json.js --test
             - name: Check licenses are up to date
-              run: node ./scripts/tasks/generate-license-files.js --test
+              run: node ./scripts/tasks/generate-license-files.mjs --test
             - name: Verify @lwc/shared is tree-shakable
               run: node ./scripts/tasks/verify-treeshakable.mjs ./packages/@lwc/shared/dist/index.js
             - name: Verify that dependencies are declared

.husky/pre-push

@@ -1,5 +1,5 @@
 set -e
 node ./scripts/tasks/check-and-rewrite-package-json.js --test
-node ./scripts/tasks/generate-license-files.js --test
+node ./scripts/tasks/generate-license-files.mjs --test
 node ./scripts/tasks/verify-treeshakable.mjs ./packages/@lwc/shared/dist/index.js
 node ./scripts/tasks/check-imports-are-declared-dependencies.js

package.json

@@ -81,7 +81,7 @@
         "*.{js,mjs,ts,only,skip}": "eslint --cache",
         "*.{css,js,json,md,mjs,ts,yaml,yml}": "prettier --check",
         "{packages/**/package.json,scripts/tasks/check-and-rewrite-package-json.js}": "node ./scripts/tasks/check-and-rewrite-package-json.js --test",
-        "{LICENSE-CORE.md,**/LICENSE.md,yarn.lock,scripts/tasks/generate-license-files.js,scripts/shared/bundled-dependencies.js}": "node ./scripts/tasks/generate-license-files.js --test"
+        "{LICENSE-CORE.md,**/LICENSE.md,yarn.lock,scripts/tasks/generate-license-files.mjs,scripts/shared/bundled-dependencies.js}": "node ./scripts/tasks/generate-license-files.mjs --test"
     },
     "workspaces": [
         "packages/@lwc/*",

scripts/tasks/generate-license-files.mjs

@@ -0,0 +1,122 @@
+import path from 'node:path';
+import { readFile, writeFile, stat, readdir } from 'node:fs/promises';
+import { createRequire } from 'node:module';
+import { fileURLToPath } from 'node:url';
+import prettier from 'prettier';
+import { BUNDLED_DEPENDENCIES } from '../shared/bundled-dependencies.js';
+
+// We're using ESM here, but some packages still only export CJS, so we also need `require`
+const require = createRequire(import.meta.url);
+
+const atLwcPackages = (await readdir('packages/@lwc'))
+    // skip dotfiles like .DS_Store
+    .filter((_) => !_.startsWith('.'))
+    .map((_) => `@lwc/${_}`);
+
+// Generate our LICENSE files for each package, including any bundled dependencies
+// This is modeled after how Rollup does it:
+// https://github.com/rollup/rollup/blob/0b665c3/build-plugins/generate-license-file.ts
+
+// Async fs.existsSync
+async function exists(filename) {
+    try {
+        await stat(filename);
+        return true;
+    } catch (_err) {
+        return false;
+    }
+}
+
+/**
+ * Tries `require.resolve` with additional paths (`packages/@lwc/___/node_modules`)
+ * and `import.meta.resolve` (unmodified) to find a package's entrypoint.
+ */
+function tryResolve(specifier) {
+    try {
+        // As far as I can tell, there's no way to modify the `import` lookup paths
+        return fileURLToPath(import.meta.resolve(specifier));
+    } catch (err) {
+        // We expect to see missing packages, but throw other errors
+        if (err.code !== 'ERR_MODULE_NOT_FOUND') {
+            throw err;
+        }
+    }
+    // `require.resolve` accepts a second parameter of additional places to look
+    return require.resolve(specifier, {
+        paths: atLwcPackages.map((pkg) => path.join('packages', pkg, 'node_modules')),
+    });
+}
+
+/**
+ * Finds a dependency in our monorepo.
+ * @param {string} specifier - package name to find
+ */
+function findPackageDirectory(specifier) {
+    const resolved = tryResolve(specifier);
+    // An import can resolve to a nested directory, e.g. dist/index.js. We want the package
+    // root, which will always be the last node_modules/${specifier}.
+    const lookup = path.join('/node_modules', specifier);
+    return resolved.slice(0, resolved.lastIndexOf(lookup) + lookup.length);
+}
+
+async function findLicenseText(depName) {
+    // Iterate through possible names for the license file
+    const names = ['LICENSE', 'LICENSE.md', 'LICENSE.txt'];
+
+    const resolvedDepPath = findPackageDirectory(depName);
+
+    for (const name of names) {
+        const fullFilePath = path.join(resolvedDepPath, name);
+        if (await exists(fullFilePath)) {
+            return (await readFile(fullFilePath, 'utf-8')).trim();
+        }
+    }
+
+    // Get the license from the package.json if we can't find it elsewhere
+    const { license, version } = JSON.parse(
+        await readFile(path.join(resolvedDepPath, 'package.json'), 'utf-8')
+    );
+
+    return `${license} license defined in package.json in v${version}.`;
+}
+
+const coreLicense = await readFile('LICENSE-CORE.md', 'utf-8');
+
+const bundledLicenses = await Promise.all(
+    BUNDLED_DEPENDENCIES.map(async (depName) => {
+        return `## ${depName}\n\n` + (await findLicenseText(depName));
+    })
+);
+const newLicense =
+    `# LWC core license\n\n${coreLicense}\n# Licenses of bundled dependencies\n\n${bundledLicenses.join(
+        '\n'
+    )}`.trim() + '\n';
+
+const formattedLicense = await prettier.format(newLicense, {
+    parser: 'markdown',
+});
+
+// Check against current top-level license for changes
+const shouldWarnChanges =
+    process.argv.includes('--test') && formattedLicense !== (await readFile('LICENSE.md', 'utf-8'));
+
+// Top level license
+await writeFile('LICENSE.md', formattedLicense, 'utf-8');
+
+// License file for each package as well, so that we publish it to npm
+
+const packages = ['lwc', ...atLwcPackages];
+
+await Promise.all(
+    packages.map(async (pkg) => {
+        await writeFile(path.join('packages/', pkg, 'LICENSE.md'), formattedLicense, 'utf-8');
+    })
+);
+
+if (shouldWarnChanges) {
+    const relativeFilename = path.relative(process.cwd(), import.meta.filename);
+    throw new Error(
+        'Either the LWC core license or the license of a bundled dependency has been updated.\n' +
+            `Please run \`node ${relativeFilename}\` and commit the result.`
+    );
+}