fix(pipelines): stack outputs used in stackSteps not recognized (#17311)

fixes #17272


----

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

packages/@aws-cdk/pipelines/lib/helpers-internal/pipeline-queries.ts

@@ -17,6 +17,9 @@ export class PipelineQueries {
       steps.push(...wave.pre, ...wave.post);
       for (const stage of wave.stages) {
         steps.push(...stage.pre, ...stage.post);
+        for (const stackDeployment of stage.stacks) {
+          steps.push(...stackDeployment.pre, ...stackDeployment.changeSet, ...stackDeployment.post);
+        }
       }
     }
 

packages/@aws-cdk/pipelines/test/blueprint/helpers-internal/pipeline-queries.test.ts

@@ -0,0 +1,99 @@
+/* eslint-disable import/no-extraneous-dependencies */
+import '@aws-cdk/assert-internal/jest';
+import * as cdkp from '../../../lib';
+import { PipelineQueries } from '../../../lib/helpers-internal/pipeline-queries';
+import { AppWithOutput, TestApp } from '../../testhelpers/test-app';
+
+let app: TestApp;
+
+beforeEach(() => {
+  app = new TestApp();
+});
+
+afterEach(() => {
+  app.cleanup();
+});
+
+describe('pipeline-queries', () => {
+
+  describe('stackOutputsReferenced', () => {
+    let blueprint: Blueprint;
+    let stageDeployment: cdkp.StageDeployment;
+    let step: cdkp.ShellStep;
+    let queries: PipelineQueries;
+    let stackDeployment: cdkp.StackDeployment;
+    let outputName: string | undefined;
+    beforeEach(() => {
+      blueprint = new Blueprint(app, 'Bp', {
+        synth: new cdkp.ShellStep('Synth', {
+          input: cdkp.CodePipelineSource.gitHub('test/test', 'main'),
+          commands: ['build'],
+        }),
+      });
+      const stage = new AppWithOutput(app, 'CrossAccount');
+      outputName = 'MyOutput';
+      stageDeployment = blueprint.addStage(stage);
+      stackDeployment = stageDeployment.stacks[0];
+      expect(stackDeployment).not.toBeUndefined();
+      step = new cdkp.ShellStep('test', {
+        input: cdkp.CodePipelineSource.gitHub('test/test', 'main'),
+        commands: ['build'],
+        envFromCfnOutputs: {
+          INPUT: stage.theOutput,
+        },
+      });
+      queries = new PipelineQueries(blueprint);
+    });
+
+    const cases = [
+      {
+        description: 'output referenced in stage pre step',
+        additionalSetup: () => stageDeployment.addPre(step),
+        expectedResultGetter: () => [outputName],
+      },
+      {
+        description: 'output referenced in stage post step',
+        additionalSetup: () => stageDeployment.addPost(step),
+        expectedResultGetter: () => [outputName],
+      },
+      {
+        description: 'output referenced in stack pre step',
+        additionalSetup: () => stackDeployment.addStackSteps([step], [], []),
+        expectedResultGetter: () => [outputName],
+      },
+      {
+        description: 'output referenced in stack changeSet step',
+        additionalSetup: () => stackDeployment.addStackSteps([], [step], []),
+        expectedResultGetter: () => [outputName],
+      },
+      {
+        description: 'output referenced in stack post step',
+        additionalSetup: () => stackDeployment.addStackSteps([], [], [step]),
+        expectedResultGetter: () => [outputName],
+      },
+      {
+        description: 'output not referenced',
+        additionalSetup: () => { },
+        expectedResultGetter: () => [],
+      },
+
+    ];
+
+    cases.forEach(testCase => {
+      test(testCase.description, () => {
+        //WHEN
+        testCase.additionalSetup();
+
+        //THEN
+        expect(queries.stackOutputsReferenced(stackDeployment)).toEqual(testCase.expectedResultGetter());
+      });
+    });
+
+  });
+});
+
+
+class Blueprint extends cdkp.PipelineBase {
+  protected doBuildPipeline(): void {
+  }
+}