Remove build package.json dirty state check (#55420)

Summary:
Pull Request resolved: #55420

After #54857 (use of the "publishConfig" field), this check is no longer necessary, since `yarn build` will no longer make changes to any checked in files.

In the (expectedly) rare case that `yarn build --prepack` changes are committed (only intended for CI), Flow will also fail independently.

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D92397786

fbshipit-source-id: 872cc91b62295cdb6d8c2799cffb8a4cadc4106e

Author: huntie

.github/actions/lint/action.yml

@@ -29,9 +29,6 @@ runs:
     - name: Lint file structure
       shell: bash
       run: ./.github/workflow-scripts/lint_files.sh
-    - name: Verify not committing repo after running build
-      shell: bash
-      run: yarn run build --validate
     - name: Run flowcheck
       shell: bash
       run: yarn flow-check

scripts/build/build.js

@@ -37,15 +37,14 @@ const config = {
   allowPositionals: true,
   options: {
     prepack: {type: 'boolean'},
-    validate: {type: 'boolean'},
     help: {type: 'boolean'},
   },
 };
 
 async function build() {
   const {
     positionals: packageNames,
-    values: {prepack, validate, help},
+    values: {prepack, help},
     /* $FlowFixMe[incompatible-type] Natural Inference rollout. See
      * https://fburl.com/workplace/6291gfvu */
   } = parseArgs(config);
@@ -62,47 +61,28 @@ async function build() {
   Options:
     --prepack         Run the ./prepack.js script after building, applying
                       package.json "publishConfig" changes to the working copy.
-                      This is usually run before npm publish.
-    --validate        Validate that no build artifacts have been accidentally
-                      committed.
+                      (This is usually run later in CI before npm publish).
     `);
     process.exitCode = 0;
     return;
   }
 
-  if (!validate) {
-    console.log(
-      '\n' + styleText(['bold', 'inverse'], 'Building packages') + '\n',
-    );
-  }
+  console.log(
+    '\n' + styleText(['bold', 'inverse'], 'Building packages') + '\n',
+  );
 
   const packagesToBuild = packageNames.length
     ? packageNames.filter(packageName => packageName in buildConfig.packages)
     : Object.keys(buildConfig.packages);
 
   let ok = true;
   for (const packageName of packagesToBuild) {
-    if (validate) {
-      ok &&= await checkPackage(packageName);
-    } else {
-      await buildPackage(packageName, prepack);
-    }
+    await buildPackage(packageName, prepack);
   }
 
   process.exitCode = ok ? 0 : 1;
 }
 
-async function checkPackage(packageName /*: string */) /*: Promise<boolean> */ {
-  const artifacts = await exportedBuildArtifacts(packageName);
-  if (artifacts.length > 0) {
-    console.log(
-      `${styleText('bgRed', packageName)}: has been built and the ${styleText('bold', 'build artifacts')} committed to the repository. This will break Flow checks.`,
-    );
-    return false;
-  }
-  return true;
-}
-
 async function buildPackage(packageName /*: string */, prepack /*: boolean */) {
   try {
     const {emitTypeScriptDefs} = getBuildOptions(packageName);
@@ -248,33 +228,6 @@ type PackageJson = {
 };
 */
 
-function isStringOnly(entries /*: mixed */) /*: entries is string */ {
-  return typeof entries === 'string';
-}
-
-async function exportedBuildArtifacts(
-  packageName /*: string */,
-) /*: Promise<string[]> */ {
-  const packagePath = path.resolve(PACKAGES_DIR, packageName, 'package.json');
-  const pkg /*: PackageJson */ = JSON.parse(
-    await fs.readFile(packagePath, 'utf8'),
-  );
-  if (pkg.exports == null) {
-    throw new Error(
-      packageName +
-        ' does not define an "exports" field in its package.json. As part ' +
-        'of the build setup, this field must be used in order to rewrite ' +
-        'paths to built files in production.',
-    );
-  }
-
-  return Object.values(pkg.exports)
-    .filter(isStringOnly)
-    .filter(filepath =>
-      path.dirname(filepath).split(path.sep).includes(BUILD_DIR),
-    );
-}
-
 /**
  * Get the set of Flow entry points to build.
  *

scripts/run-ci-javascript-tests.js

@@ -53,10 +53,9 @@ try {
 
   describe('Test: feature flags codegen');
   execAndLog(`${YARN_BINARY} run featureflags --verify-unchanged`);
+
   describe('Test: eslint');
   execAndLog(`${YARN_BINARY} run lint`);
-  describe('Test: No JS build artifacts');
-  execAndLog(`${YARN_BINARY} run build --validate`);
 
   describe('Test: Validate JS API snapshot');
   execAndLog(`${YARN_BINARY} run build-types --validate`);