chore: pr labeler workflow (#178)

equivalent to this file in aws/aws-cdk except `auto-approve` is governed
by projen already:
https://github.com/aws/aws-cdk/blob/main/.github/workflows/pr-labeler.yml.
will copy over labels from linked issues to the PR.

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

---------

Signed-off-by: github-actions <[email protected]>
Co-authored-by: github-actions <[email protected]>

Author: kaizencc

.gitattributes

@@ -8,6 +8,7 @@ import { CodeCovWorkflow } from './projenrc/codecov';
 import { ESLINT_RULES } from './projenrc/eslint';
 import { IssueLabeler } from './projenrc/issue-labeler';
 import { JsiiBuild } from './projenrc/jsii';
+import { PrLabeler } from './projenrc/pr-labeler';
 import { RecordPublishingTimestamp } from './projenrc/record-publishing-timestamp';
 import { S3DocsPublishing } from './projenrc/s3-docs-publishing';
 
@@ -1403,5 +1404,6 @@ new CodeCovWorkflow(repo, {
 });
 
 new IssueLabeler(repo);
+new PrLabeler(repo);
 
 repo.synth();

.github/workflows/pr-labeler.yml

@@ -1,6 +1,7 @@
 import { Component, github } from 'projen';
 import { JobPermission } from 'projen/lib/github/workflows-model';
 import { TypeScriptProject } from 'projen/lib/typescript';
+import { GitHubToken, stringifyList } from './util';
 
 const OSDS_DEVS = ['ashishdhingra', 'khushail', 'hunhsieh'];
 const AREA_AFFIXES = ['@aws-cdk/'];
@@ -13,11 +14,6 @@ const AREA_PARAMS = [
   { area: 'cdk-assets', keywords: ['assets', 'cdk-assets'], labels: ['cdk-assets'] },
 ];
 
-enum GitHubToken {
-  GITHUB_TOKEN = 'secrets.GITHUB_TOKEN',
-  PROJEN_GITHUB_TOKEN = 'secrets.PROJEN_GITHUB_TOKEN',
-}
-
 /**
  * See https://github.com/aws-github-ops/aws-issue-triage-manager
  */
@@ -41,10 +37,6 @@ interface TriageManagerOptions {
   githubToken?: GitHubToken;
 }
 
-function stringifyList(list: string[]) {
-  return `[${list.join('|')}]`;
-}
-
 function triageManagerJob(triageManagerOptions: TriageManagerOptions) {
   return {
     name: 'Triage Manager',

.gitignore

@@ -0,0 +1,56 @@
+import { Component, github } from 'projen';
+import { JobPermission } from 'projen/lib/github/workflows-model';
+import { TypeScriptProject } from 'projen/lib/typescript';
+import { GitHubToken, stringifyList } from './util';
+
+/**
+ * See https://github.com/cdklabs/pr-triage-manager
+ */
+interface PrLabelerOptions {
+  /**
+   * @default GitHubToken.GITHUB_TOKEN
+   */
+  githubToken?: GitHubToken;
+  priorityLabels?: string[];
+  classificationLabels?: string[];
+  onPulls?: boolean;
+}
+
+function prLabelerJob(prLabelerOptions: PrLabelerOptions = {}) {
+  return {
+    name: 'PR Labeler',
+    runsOn: ['aws-cdk_ubuntu-latest_4-core'],
+    permissions: { issues: JobPermission.WRITE, pullRequests: JobPermission.WRITE },
+    steps: [
+      {
+        name: 'PR Labeler',
+        uses: 'cdklabs/pr-triage-manager@main',
+        with: {
+          'github-token': `\${{ ${prLabelerOptions.githubToken ?? 'secrets.GITHUB_TOKEN'} }}`,
+          'priority-labels': prLabelerOptions.priorityLabels ? stringifyList(prLabelerOptions.priorityLabels) : undefined,
+          'classification-labels': prLabelerOptions.classificationLabels ? stringifyList(prLabelerOptions.classificationLabels) : undefined,
+          'on-pulls': prLabelerOptions.onPulls,
+        },
+      },
+    ],
+  };
+}
+
+export class PrLabeler extends Component {
+  public readonly workflow: github.GithubWorkflow;
+
+  constructor(repo: TypeScriptProject) {
+    super(repo);
+
+    if (!repo.github) {
+      throw new Error('Given repository does not have a GitHub component');
+    }
+
+    this.workflow = repo.github.addWorkflow('pr-labeler');
+    this.workflow.on({
+      pullRequestTarget: { types: ['opened', 'edited', 'reopened'] },
+    });
+
+    this.workflow.addJob('copy-labels', prLabelerJob());
+  }
+}

.projen/files.json

@@ -0,0 +1,8 @@
+export enum GitHubToken {
+  GITHUB_TOKEN = 'secrets.GITHUB_TOKEN',
+  PROJEN_GITHUB_TOKEN = 'secrets.PROJEN_GITHUB_TOKEN',
+}
+
+export function stringifyList(list: string[]) {
+  return `[${list.join('|')}]`;
+}