feat(codepipeline-actions): expose PR-specific variables in CodeStarConnectionsSourceAction

packages/@aws-cdk-testing/framework-integ/test/aws-codepipeline-actions/test/integ.pipeline-with-pipeline-triggers.js.snapshot/aws-cdk-codepipeline-with-pipeline-triggers.template.json

@@ -1284,7 +1284,7 @@
          "ProjectName": {
           "Ref": "MyProject2B52B17CC"
          },
-         "EnvironmentVariables": "[{\"name\":\"CommitId\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.CommitId}\"}]"
+         "EnvironmentVariables": "[{\"name\":\"CommitId\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.CommitId}\"},{\"name\":\"SourceBranchName\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.SourceBranchName}\"},{\"name\":\"DestinationBranchName\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.DestinationBranchName}\"},{\"name\":\"PullRequestId\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.PullRequestId}\"},{\"name\":\"PullRequestTitle\",\"type\":\"PLAINTEXT\",\"value\":\"#{Source_CodeStarConnectionsSourceAction2_NS.PullRequestTitle}\"}]"
         },
         "InputArtifacts": [
          {

packages/@aws-cdk-testing/framework-integ/test/aws-codepipeline-actions/test/integ.pipeline-with-pipeline-triggers.ts

@@ -94,6 +94,10 @@ new codepipeline.Pipeline(stack, 'Pipeline2', {
           outputs: [new codepipeline.Artifact()],
           environmentVariables: {
             CommitId: { value: sourceAction2.variables.commitId },
+            SourceBranchName: { value: sourceAction2.variables.sourceBranchName },
+            DestinationBranchName: { value: sourceAction2.variables.destinationBranchName },
+            PullRequestId: { value: sourceAction2.variables.pullRequestId },
+            PullRequestTitle: { value: sourceAction2.variables.pullRequestTitle },
           },
         }),
       ],

packages/aws-cdk-lib/aws-codepipeline-actions/README.md

@@ -246,6 +246,43 @@ new codepipeline_actions.CodeBuildAction({
 });
 ```
 
+When a pipeline is triggered by a pull request event, additional PR-specific variables are available:
+
+```ts
+declare const project: codebuild.Project;
+
+const sourceOutput = new codepipeline.Artifact();
+const sourceAction = new codepipeline_actions.CodeStarConnectionsSourceAction({
+  actionName: 'BitBucket_Source',
+  owner: 'aws',
+  repo: 'aws-cdk',
+  output: sourceOutput,
+  connectionArn: 'arn:aws:codestar-connections:us-east-1:123456789012:connection/12345678-abcd-12ab-34cdef5678gh',
+});
+
+// later:
+
+new codepipeline_actions.CodeBuildAction({
+  actionName: 'CodeBuild',
+  project,
+  input: sourceOutput,
+  environmentVariables: {
+    SOURCE_BRANCH: {
+      value: sourceAction.variables.sourceBranchName,
+    },
+    DESTINATION_BRANCH: {
+      value: sourceAction.variables.destinationBranchName,
+    },
+    PULL_REQUEST_ID: {
+      value: sourceAction.variables.pullRequestId,
+    },
+    PULL_REQUEST_TITLE: {
+      value: sourceAction.variables.pullRequestTitle,
+    },
+  },
+});
+```
+
 ### AWS S3 Source
 
 To use an S3 Bucket as a source in CodePipeline:

packages/aws-cdk-lib/aws-codepipeline-actions/lib/codestar-connections/source-action.ts

@@ -20,6 +20,14 @@ export interface CodeStarSourceVariables {
   readonly commitMessage: string;
   /** The connection ARN this source uses. */
   readonly connectionArn: string;
+  /** The source branch name of the PR that triggered the pipeline execution. Only available for PR-triggered executions. */
+  readonly sourceBranchName: string;
+  /** The destination branch name (target) of the PR that triggered the pipeline execution. Only available for PR-triggered executions. */
+  readonly destinationBranchName: string;
+  /** The ID of the PR that triggered the pipeline execution. Only available for PR-triggered executions. */
+  readonly pullRequestId: string;
+  /** The title of the PR that triggered the pipeline execution. Only available for PR-triggered executions. */
+  readonly pullRequestTitle: string;
 }
 
 /**
@@ -124,6 +132,10 @@ export class CodeStarConnectionsSourceAction extends Action {
       commitId: this.variableExpression('CommitId'),
       commitMessage: this.variableExpression('CommitMessage'),
       connectionArn: this.variableExpression('ConnectionArn'),
+      sourceBranchName: this.variableExpression('SourceBranchName'),
+      destinationBranchName: this.variableExpression('DestinationBranchName'),
+      pullRequestId: this.variableExpression('PullRequestId'),
+      pullRequestTitle: this.variableExpression('PullRequestTitle'),
     };
   }
 

packages/aws-cdk-lib/aws-codepipeline-actions/test/codestar-connections/codestar-connections-source-action.test.ts

@@ -201,6 +201,62 @@ describe('CodeStar Connections source Action', () => {
     });
   });
 
+  test('exposes PR-specific variables', () => {
+    const stack = new Stack();
+    const sourceOutput = new codepipeline.Artifact();
+    const sourceAction = new cpactions.CodeStarConnectionsSourceAction({
+      actionName: 'BitBucket',
+      owner: 'aws',
+      repo: 'aws-cdk',
+      output: sourceOutput,
+      connectionArn: 'arn:aws:codestar-connections:us-east-1:123456789012:connection/12345678-abcd-12ab-34cdef5678gh',
+    });
+
+    new codepipeline.Pipeline(stack, 'Pipeline', {
+      stages: [
+        {
+          stageName: 'Source',
+          actions: [sourceAction],
+        },
+        {
+          stageName: 'Build',
+          actions: [
+            new cpactions.CodeBuildAction({
+              actionName: 'CodeBuild',
+              project: new codebuild.PipelineProject(stack, 'MyProject'),
+              input: sourceOutput,
+              environmentVariables: {
+                SourceBranchName: { value: sourceAction.variables.sourceBranchName },
+                DestinationBranchName: { value: sourceAction.variables.destinationBranchName },
+                PullRequestId: { value: sourceAction.variables.pullRequestId },
+                PullRequestTitle: { value: sourceAction.variables.pullRequestTitle },
+              },
+            }),
+          ],
+        },
+      ],
+    });
+
+    Template.fromStack(stack).hasResourceProperties('AWS::CodePipeline::Pipeline', {
+      'Stages': [
+        {
+          'Name': 'Source',
+        },
+        {
+          'Name': 'Build',
+          'Actions': [
+            {
+              'Name': 'CodeBuild',
+              'Configuration': {
+                'EnvironmentVariables': '[{"name":"SourceBranchName","type":"PLAINTEXT","value":"#{Source_BitBucket_NS.SourceBranchName}"},{"name":"DestinationBranchName","type":"PLAINTEXT","value":"#{Source_BitBucket_NS.DestinationBranchName}"},{"name":"PullRequestId","type":"PLAINTEXT","value":"#{Source_BitBucket_NS.PullRequestId}"},{"name":"PullRequestTitle","type":"PLAINTEXT","value":"#{Source_BitBucket_NS.PullRequestTitle}"}]',
+              },
+            },
+          ],
+        },
+      ],
+    });
+  });
+
   test('fail if variable from unused action is referenced', () => {
     const app = new App();
     const stack = new Stack(app);