Separate sizebot for experimental builds (#17100)

Configures the sizebot to leave a second comment that tracks the
experimental build artifacts.

.circleci/config.yml

@@ -205,7 +205,26 @@ jobs:
       # This runs in the process_artifacts job, too, but it's faster to run
       # this step in both jobs instead of running the jobs sequentially
       - run: node ./scripts/rollup/consolidateBundleSizes.js
-      - run: node ./scripts/tasks/danger
+      - run:
+          environment:
+            RELEASE_CHANNEL: stable
+          command: node ./scripts/tasks/danger
+
+  sizebot_experimental:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace: *attach_workspace
+      - *restore_yarn_cache
+      - *run_yarn
+      # This runs in the process_artifacts job, too, but it's faster to run
+      # this step in both jobs instead of running the jobs sequentially
+      - run: node ./scripts/rollup/consolidateBundleSizes.js
+      - run:
+          environment:
+            RELEASE_CHANNEL: experimental
+          command: node ./scripts/tasks/danger
 
   lint_build:
     docker: *docker
@@ -370,6 +389,9 @@ workflows:
       - process_artifacts_experimental:
           requires:
             - build_experimental
+      - sizebot_experimental:
+          requires:
+            - build_experimental
       - test_build_experimental:
           requires:
             - build_experimental

dangerfile.js

@@ -32,6 +32,14 @@ const {generateResultsArray} = require('./scripts/rollup/stats');
 const {existsSync, readFileSync} = require('fs');
 const {exec} = require('child_process');
 
+// This must match the name of the CI job that creates the build artifacts
+const RELEASE_CHANNEL =
+  process.env.RELEASE_CHANNEL === 'experimental' ? 'experimental' : 'stable';
+const artifactsJobName =
+  process.env.RELEASE_CHANNEL === 'experimental'
+    ? 'process_artifacts_experimental'
+    : 'process_artifacts';
+
 if (!existsSync('./build/bundle-sizes.json')) {
   // This indicates the build failed previously.
   // In that case, there's nothing for the Dangerfile to do.
@@ -117,6 +125,8 @@ function git(args) {
     return;
   }
 
+  markdown(`## Size changes (${RELEASE_CHANNEL})`);
+
   const upstreamRef = danger.github.pr.base.ref;
   await git(`remote add upstream https://github.com/facebook/react.git`);
   await git('fetch upstream');
@@ -135,8 +145,7 @@ function git(args) {
     }
     for (let i = 0; i < statuses.length; i++) {
       const status = statuses[i];
-      // This must match the name of the CI job that creates the build artifacts
-      if (status.context === 'ci/circleci: process_artifacts') {
+      if (status.context === `ci/circleci: ${artifactsJobName}`) {
         if (status.state === 'success') {
           baseCIBuildId = /\/facebook\/react\/([0-9]+)/.exec(
             status.target_url

scripts/tasks/danger.js

@@ -14,14 +14,21 @@ const extension = process.platform === 'win32' ? '.cmd' : '';
 
 // sizebot public_repo token (this is publicly visible on purpose)
 const token = '0a7d5c3cad9a6dbec2d9' + '9a5222cf49062a4c1ef7';
-spawn(path.join('node_modules', '.bin', 'danger-ci' + extension), [], {
-  // Allow colors to pass through
-  stdio: 'inherit',
-  env: {
-    ...process.env,
-    DANGER_GITHUB_API_TOKEN: token,
-  },
-}).on('close', function(code) {
+spawn(
+  path.join('node_modules', '.bin', 'danger-ci' + extension),
+  [
+    '--id',
+    process.env.RELEASE_CHANNEL === 'experimental' ? 'experimental' : 'stable',
+  ],
+  {
+    // Allow colors to pass through
+    stdio: 'inherit',
+    env: {
+      ...process.env,
+      DANGER_GITHUB_API_TOKEN: token,
+    },
+  }
+).on('close', function(code) {
   if (code !== 0) {
     console.error('Danger failed');
   } else {