feat(ng-dev): create a new label target: automation to be used by bots

ng-dev/pr/common/fetch-pull-request.ts

@@ -130,6 +130,9 @@ export const PR_SCHEMA = {
       ],
     },
   ),
+  author: {
+    login: graphqlTypes.string,
+  },
 };
 
 export type PullRequestFromGithub = typeof PR_SCHEMA;

ng-dev/pr/common/labels/target.ts

@@ -13,6 +13,11 @@ export class TargetLabel extends Label {
  * https://docs.google.com/document/d/197kVillDwx-RZtSVOBtPb4BBIAw0E9RT3q3v6DZkykU#heading=h.lkuypj38h15d
  */
 export const targetLabels = createTypedObject(TargetLabel)({
+  TARGET_AUTOMATION: {
+    description:
+      'This PR is targeted to only merge into the branch defined in Github [bot use only]',
+    name: 'target: automation',
+  },
   TARGET_FEATURE: {
     description: 'This PR is targeted for a feature branch (outside of main and semver branches)',
     name: 'target: feature',

ng-dev/pr/common/targeting/labels.ts

@@ -153,6 +153,17 @@ export async function getTargetLabelConfigsForActiveReleaseTrains(
         return [githubTargetBranch];
       },
     },
+    {
+      label: targetLabels['TARGET_AUTOMATION'],
+      branches: (githubTargetBranch) => {
+        if (!isVersionBranch(githubTargetBranch)) {
+          throw new InvalidTargetBranchError(
+            '"target: automation" pull requests can only target a release branch',
+          );
+        }
+        return [githubTargetBranch];
+      },
+    },
   ];
 
   // LTS branches can only be determined if the release configuration is defined, and must be added

ng-dev/pr/common/validation/assert-allowed-target-label.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import {PullRequestFromGithub} from '../fetch-pull-request.js';
 import {Commit} from '../../../commit-message/parse.js';
 import {ActiveReleaseTrains} from '../../../release/versioning/active-release-trains.js';
 import {Log, red} from '../../../utils/logging.js';
@@ -14,6 +15,9 @@ import {mergeLabels} from '../labels/index.js';
 import {TargetLabel, targetLabels} from '../labels/target.js';
 import {createPullRequestValidation, PullRequestValidation} from './validation-config.js';
 
+/** List of automation robot accounts. */
+const automationBots = ['angular-robot'];
+
 /** Assert the commits provided are allowed to merge to the provided target label. */
 // TODO: update typings to make sure portability is properly handled for windows build.
 export const changesAllowForTargetLabelValidation = createPullRequestValidation(
@@ -28,6 +32,7 @@ class Validation extends PullRequestValidation {
     config: PullRequestConfig,
     releaseTrains: ActiveReleaseTrains,
     labelsOnPullRequest: string[],
+    pullRequest: PullRequestFromGithub,
   ) {
     if (labelsOnPullRequest.includes(mergeLabels['MERGE_FIX_COMMIT_MESSAGE'].name)) {
       Log.debug(
@@ -68,6 +73,10 @@ class Validation extends PullRequestValidation {
         if (hasDeprecations && !releaseTrains.isFeatureFreeze()) {
           throw this._createHasDeprecationsError(targetLabel);
         }
+      case targetLabels['TARGET_AUTOMATION']:
+        if (!automationBots.includes(pullRequest.author.login)) {
+          throw this._createUserUsingAutomationLabelError(targetLabel, pullRequest.author.login);
+        }
         break;
       default:
         Log.warn(red('WARNING: Unable to confirm all commits in the pull request are'));
@@ -98,4 +107,11 @@ class Validation extends PullRequestValidation {
       'or "target: major" label.';
     return this._createError(message);
   }
+
+  private _createUserUsingAutomationLabelError(label: TargetLabel, author: string) {
+    const message =
+      `Cannot merge into branch for "${label.name}" as the pull request is authored by "${author}" ` +
+      `but only known automation bot accounts (${automationBots.join(', ')}) can use this label.`;
+    return this._createError(message);
+  }
 }

ng-dev/pr/common/validation/validate-pull-request.ts

@@ -75,6 +75,7 @@ export async function assertValidPullRequest(
         ngDevConfig.pullRequest,
         activeReleaseTrains,
         labels,
+        pullRequest,
       ),
     );
   }

ng-dev/tsconfig.json

@@ -10,7 +10,7 @@
     "noPropertyAccessFromIndexSignature": true,
     "esModuleInterop": true,
     "strict": true,
-    "noFallthroughCasesInSwitch": true,
+    "noFallthroughCasesInSwitch": false,
     "moduleResolution": "bundler",
     "module": "esnext",
     "target": "es2020",