Simplify logic to choose if we need to build hermes from source or no…

…t. (#34232)

Summary:
Pull Request resolved: #34232

This diff simplify the logic to decide whether we want to build hermes from source or not.

The requirement we have is that we don't want our users to build hermes.
So, we don't want to build hermes when there is a precompiled tarball available, while we want to build hermes in CI.

## Changelog

[General][Changed] - Build hermes when in CI and not when there is a tarball

Reviewed By: cortinico

Differential Revision: D37999748

fbshipit-source-id: 7d9cab51c37fb47db216055c057a22081e10df07

scripts/hermes/hermes-utils.js

@@ -15,7 +15,6 @@ const {execSync} = require('child_process');
 
 const SDKS_DIR = path.normalize(path.join(__dirname, '..', '..', 'sdks'));
 const HERMES_DIR = path.join(SDKS_DIR, 'hermes');
-const DEFAULT_HERMES_TAG = 'main';
 const HERMES_TAG_FILE_PATH = path.join(SDKS_DIR, '.hermesversion');
 const HERMES_TARBALL_BASE_URL = 'https://github.com/facebook/hermes/tarball/';
 const HERMES_TARBALL_DOWNLOAD_DIR = path.join(SDKS_DIR, 'download');
@@ -162,65 +161,8 @@ function isTestingAgainstLocalHermesTarball() {
   return 'HERMES_ENGINE_TARBALL_PATH' in process.env;
 }
 
-function isOnAReactNativeReleaseBranch() {
-  try {
-    let currentBranch = execSync('git rev-parse --abbrev-ref HEAD')
-      .toString()
-      .trim();
-    let currentRemote = execSync('git config --get remote.origin.url')
-      .toString()
-      .trim();
-    return (
-      currentBranch.endsWith('-stable') &&
-      currentRemote.endsWith('facebook/react-native.git')
-    );
-  } catch (error) {
-    // If not inside a git repo, we're going to fail here and return.
-    return false;
-  }
-}
-
-function isOnAReactNativeReleaseTag() {
-  try {
-    // If on a named tag, this method will return the tag name.
-    // If not, it will throw as the return code is not 0.
-    execSync('git describe --exact-match HEAD', {stdio: 'ignore'});
-  } catch (error) {
-    return false;
-  }
-  let currentRemote = execSync('git config --get remote.origin.url')
-    .toString()
-    .trim();
-  return currentRemote.endsWith('facebook/react-native.git');
-}
-
-function isRequestingLatestCommitFromHermesMainBranch() {
-  const hermesTag = readHermesTag();
-  return hermesTag === DEFAULT_HERMES_TAG;
-}
-
-function isPRAgainstStable(pullRequest) {
-  if (pullRequest == null) {
-    return false;
-  }
-
-  const prComponents = pullRequest.split('/');
-  const prNumber = prComponents[prComponents.length - 1];
-  const apiURL = `https://api.github.com/repos/facebook/react-native/pulls/${prNumber}`;
-  const prJson = JSON.parse(execSync(`curl ${apiURL}`).toString());
-  const baseBranch = prJson.base.label;
-
-  return baseBranch.endsWith('-stable');
-}
-
-function shouldBuildHermesFromSource(pullRequest) {
-  return (
-    !isTestingAgainstLocalHermesTarball() &&
-    (isOnAReactNativeReleaseBranch() ||
-      isOnAReactNativeReleaseTag() ||
-      isPRAgainstStable(pullRequest) ||
-      isRequestingLatestCommitFromHermesMainBranch())
-  );
+function shouldBuildHermesFromSource(isInCI) {
+  return !isTestingAgainstLocalHermesTarball() && isInCI;
 }
 
 function shouldUsePrebuiltHermesC(os) {

scripts/hermes/prepare-hermes-for-build.js

@@ -23,12 +23,11 @@ const {
   shouldBuildHermesFromSource,
 } = require('./hermes-utils');
 
-async function main(pullRequest) {
-  if (!shouldBuildHermesFromSource(pullRequest)) {
+async function main(isInCI) {
+  if (!shouldBuildHermesFromSource(isInCI)) {
     copyPodSpec();
     return;
   }
-
   downloadHermesTarball();
   expandHermesTarball();
   copyPodSpec();
@@ -40,8 +39,8 @@ async function main(pullRequest) {
   }
 }
 
-const pullRequest = process.argv.length > 2 ? process.argv[2] : null;
-console.log(`Pull request detected: ${pullRequest}`);
-main(pullRequest).then(() => {
+const isInCI = process.env.CI === 'true';
+
+main(isInCI).then(() => {
   process.exit(0);
 });

sdks/hermes-engine/hermes-engine.podspec

@@ -13,6 +13,8 @@ import_hermesc_file=File.join(__dir__, "..", "hermesc", "osx-bin", "ImportHermes
 package_file = File.join(__dir__, "..", "..", "package.json")
 package = JSON.parse(File.read(package_file))
 version = package['version']
+isInCI = ENV['CI'] == true
+hermestag_file = File.join(__dir__, "..", ".hermesversion")
 
 # We need to check the current git branch/remote to verify if
 # we're on a React Native release branch to actually build Hermes.
@@ -29,9 +31,8 @@ elsif version == '1000.0.0'
   Pod::UI.puts '[Hermes] Hermes needs to be compiled, installing hermes-engine may take a while...'.yellow if Object.const_defined?("Pod::UI")
   source[:git] = git
   source[:commit] = `git ls-remote https://github.com/facebook/hermes main | cut -f 1`.strip
-elsif currentremote.strip.end_with?("facebook/react-native.git") and currentbranch.strip.end_with?("-stable")
+elsif File.exists?(hermestag_file) && isInCI
   Pod::UI.puts '[Hermes] Detected that you are on a React Native release branch, building Hermes from source...'.yellow if Object.const_defined?("Pod::UI")
-  hermestag_file = File.join(__dir__, "..", ".hermesversion")
   hermestag = File.read(hermestag_file).strip
   source[:git] = git
   source[:tag] = hermestag