post diff to PR

.projenrc.ts

@@ -1,5 +1,5 @@
 import * as pj from 'projen';
-import { AwsCdkIntegrationTest, TypeScriptWorkspace, YarnMonorepo } from './projenrc';
+import { AwsCdkIntegrationTest, DiffDb, TypeScriptWorkspace, YarnMonorepo } from './projenrc';
 import { RegionalSource, Role, SingleSource, SourceProcessing } from './projenrc/update-sources';
 
 const workflowRunsOn = [
@@ -178,6 +178,13 @@ new AwsCdkIntegrationTest(repo, {
   serviceSpecTypes,
 });
 
+// Post diff of database
+new DiffDb(repo, {
+  workflowRunsOn,
+  serviceSpec: awsServiceSpec,
+  serviceSpecImporters,
+});
+
 // Update sources
 new SingleSource(repo, {
   name: 'documentation',

projenrc/diff-db.ts

@@ -0,0 +1,146 @@
+import * as pj from 'projen';
+import { yarn } from 'cdklabs-projen-project-types';
+import { relative } from 'node:path';
+
+export interface DiffDbOptions {
+  readonly workflowRunsOn: string[];
+  readonly serviceSpec: yarn.TypeScriptWorkspace;
+  readonly serviceSpecImporters: yarn.TypeScriptWorkspace;
+}
+
+export class DiffDb extends pj.Component {
+  private readonly workflow: pj.github.GithubWorkflow;
+  private readonly serviceSpec: yarn.TypeScriptWorkspace;
+  private readonly importers: yarn.TypeScriptWorkspace;
+  private readonly workflowRunsOn: string[];
+
+  public constructor(root: yarn.Monorepo, options: DiffDbOptions) {
+    super(root);
+
+    this.workflow = root.github?.tryFindWorkflow('build')!;
+    this.serviceSpec = options.serviceSpec;
+    this.importers = options.serviceSpecImporters;
+    this.workflowRunsOn = options.workflowRunsOn;
+
+    this.uploadHeadDatabase();
+    this.buildBaseDatabase();
+    this.diffDatabase();
+  }
+
+  private path(path: string) {
+    return relative(this.project.outdir, path);
+  }
+
+  private uploadHeadDatabase() {
+    this.workflow.file?.patch(
+      pj.JsonPatch.add('/jobs/build/steps/-', {
+        name: 'Upload head database',
+        uses: 'actions/upload-artifact@v3',
+        with: {
+          name: 'db.head.json.gz',
+          path: this.path(this.serviceSpec.outdir + '/db.json.gz'),
+        },
+      }),
+    );
+  }
+
+  private buildBaseDatabase() {
+    this.workflow.addJob('base-database', {
+      runsOn: this.workflowRunsOn,
+      env: { CI: 'true' },
+      permissions: {},
+      steps: [
+        {
+          name: 'Checkout',
+          uses: 'actions/checkout@v3',
+          with: {
+            ref: '${{ github.event.pull_request.base.ref }}',
+            repository: '${{ github.event.pull_request.base.repo.full_name }}',
+            lfs: true,
+          },
+        },
+        {
+          name: 'Install dependencies',
+          run: 'yarn install --check-files',
+        },
+        {
+          name: 'Build base database',
+          workingDirectory: this.path(this.serviceSpec.outdir),
+          run: 'npx projen nx compile',
+        },
+        {
+          name: 'Upload base database',
+          uses: 'actions/upload-artifact@v3',
+          with: {
+            name: 'db.base.json.gz',
+            path: this.path(this.serviceSpec.outdir + '/db.json.gz'),
+          },
+        },
+      ],
+    });
+  }
+
+  private diffDatabase() {
+    this.workflow.addJob('diff-db', {
+      needs: ['build', 'base-database'],
+      if: '!(needs.build.outputs.self_mutation_happened)',
+      runsOn: this.workflowRunsOn,
+      env: { CI: 'true' },
+      permissions: {
+        contents: pj.github.workflows.JobPermission.WRITE,
+      },
+      steps: [
+        {
+          name: 'Checkout',
+          uses: 'actions/checkout@v3',
+          with: {
+            ref: '${{ github.event.pull_request.head.ref }}',
+            repository: '${{ github.event.pull_request.head.repo.full_name }}',
+            lfs: false,
+          },
+        },
+        {
+          name: 'Install dependencies',
+          run: 'yarn install --check-files',
+        },
+        {
+          name: 'Build diff-db',
+          workingDirectory: this.path(this.importers.outdir),
+          run: 'npx projen nx compile',
+        },
+        {
+          name: 'Download base database',
+          uses: 'actions/download-artifact@v3',
+          with: {
+            name: 'db.base.json.gz',
+            path: '${{ runner.temp }}',
+          },
+        },
+        {
+          name: 'Download head database',
+          uses: 'actions/download-artifact@v3',
+          with: {
+            name: 'db.head.json.gz',
+            path: '${{ runner.temp }}',
+          },
+        },
+        {
+          id: 'diff-db',
+          name: 'Diff databases',
+          workingDirectory: this.path(this.importers.outdir),
+          run: 'echo "diff=$(./bin/import-db ${{ runner.temp }}/db.base.json.gz  ${{ runner.temp }}/db.head.json.gz)" >> "$GITHUB_OUTPUT"',
+        },
+        {
+          name: 'Comment diff',
+          if: '${{ steps.diff-db.outputs.diff }}',
+          uses: 'thollander/actions-comment-pull-request@v2',
+          with: {
+            comment_tag: 'diff-db',
+            message:
+              'Model database diff introduced between base and head branch:\n```\n${{ steps.diff-db.outputs.diff }}\n```\n',
+          },
+        },
+      ],
+    });
+  }
+}

projenrc/index.ts

@@ -1,3 +1,4 @@
 export * from './aws-cdk-integration-test';
+export * from './diff-db';
 export * from './monorepo';
 export * from './workspace';