add tests

packages/@aws-cdk-testing/cli-integ/lib/with-cli-no-stacks.ts

@@ -0,0 +1,134 @@
+import * as os from 'os';
+import * as path from 'path';
+import { TestContext } from './integ-test';
+import { RESOURCES_DIR } from './resources';
+import { AwsContext, withAws } from './with-aws';
+import { cloneDirectory, installNpmPackages, TestFixture, DEFAULT_TEST_TIMEOUT_S, CdkCliOptions } from './with-cdk-app';
+import { withTimeout } from './with-timeout';
+
+/**
+ * Higher order function to execute a block with a CliLib Integration CDK app fixture
+ */
+export function withCliLibIntegrationCdkApp<A extends TestContext & AwsContext>(block: (context: CliLibIntegrationTestFixture) => Promise<void>) {
+  return async (context: A) => {
+    const randy = context.randomString;
+    const stackNamePrefix = `cdktest-${randy}`;
+    const integTestDir = path.join(os.tmpdir(), `cdk-integ-${randy}`);
+
+    context.log(` Stack prefix:   ${stackNamePrefix}\n`);
+    context.log(` Test directory: ${integTestDir}\n`);
+    context.log(` Region:         ${context.aws.region}\n`);
+
+    await cloneDirectory(path.join(RESOURCES_DIR, 'cdk-apps', 'no-stack-app'), integTestDir, context.output);
+    const fixture = new CliLibIntegrationTestFixture(
+      integTestDir,
+      stackNamePrefix,
+      context.output,
+      context.aws,
+      context.randomString);
+
+    let success = true;
+    try {
+      const installationVersion = fixture.packages.requestedFrameworkVersion();
+
+      if (fixture.packages.majorVersion() === '1') {
+        throw new Error('This test suite is only compatible with AWS CDK v2');
+      }
+
+      const alphaInstallationVersion = fixture.packages.requestedAlphaVersion();
+      await installNpmPackages(fixture, {
+        'aws-cdk-lib': installationVersion,
+        '@aws-cdk/cli-lib-alpha': alphaInstallationVersion,
+        '@aws-cdk/aws-lambda-go-alpha': alphaInstallationVersion,
+        '@aws-cdk/aws-lambda-python-alpha': alphaInstallationVersion,
+        'constructs': '^10',
+      });
+
+      await block(fixture);
+    } catch (e: any) {
+      // We survive certain cases involving gopkg.in
+      if (errorCausedByGoPkg(e.message)) {
+        return;
+      }
+      success = false;
+      throw e;
+    } finally {
+      if (process.env.INTEG_NO_CLEAN) {
+        context.log(`Left test directory in '${integTestDir}' ($INTEG_NO_CLEAN)\n`);
+      } else {
+        await fixture.dispose(success);
+      }
+    }
+  };
+}
+
+/**
+ * Return whether or not the error is being caused by gopkg.in being down
+ *
+ * Our Go build depends on https://gopkg.in/, which has errors pretty often
+ * (every couple of days). It is run by a single volunteer.
+ */
+function errorCausedByGoPkg(error: string) {
+  // The error is different depending on what request fails. Messages recognized:
+  ////////////////////////////////////////////////////////////////////
+  //    go: github.com/aws/aws-lambda-go@v1.28.0 requires
+  //        gopkg.in/yaml.v3@v3.0.0-20200615113413-eeeca48fe776: invalid version: git ls-remote -q origin in /go/pkg/mod/cache/vcs/0901dc1ef67fcce1c9b3ae51078740de4a0e2dc673e720584ac302973af82f36: exit status 128:
+  //        remote: Cannot obtain refs from GitHub: cannot talk to GitHub: Get https://github.com/go-yaml/yaml.git/info/refs?service=git-upload-pack: net/http: request canceled (Client.Timeout exceeded while awaiting headers)
+  //        fatal: unable to access 'https://gopkg.in/yaml.v3/': The requested URL returned error: 502
+  ////////////////////////////////////////////////////////////////////
+  //    go: downloading github.com/aws/aws-lambda-go v1.28.0
+  //    go: github.com/aws/aws-lambda-go@v1.28.0 requires
+  //        gopkg.in/yaml.v3@v3.0.0-20200615113413-eeeca48fe776: unrecognized import path "gopkg.in/yaml.v3": reading https://gopkg.in/yaml.v3?go-get=1: 502 Bad Gateway
+  //        server response: Cannot obtain refs from GitHub: cannot talk to GitHub: Get https://github.com/go-yaml/yaml.git/info/refs?service=git-upload-pack: net/http: request canceled (Client.Timeout exceeded while awaiting headers)
+  ////////////////////////////////////////////////////////////////////
+  //    go: github.com/aws/aws-lambda-go@v1.28.0 requires
+  //        gopkg.in/yaml.v3@v3.0.0-20200615113413-eeeca48fe776: invalid version: git fetch -f origin refs/heads/*:refs/heads/* refs/tags/*:refs/tags/* in /go/pkg/mod/cache/vcs/0901dc1ef67fcce1c9b3ae51078740de4a0e2dc673e720584ac302973af82f36: exit status 128:
+  //        error: RPC failed; HTTP 502 curl 22 The requested URL returned error: 502
+  //        fatal: the remote end hung up unexpectedly
+  ////////////////////////////////////////////////////////////////////
+
+  return (error.includes('gopkg\.in.*invalid version.*exit status 128')
+    || error.match(/unrecognized import path[^\n]gopkg\.in/));
+}
+
+/**
+ * SAM Integration test fixture for CDK - SAM integration test cases
+ */
+export function withCliLibFixture(block: (context: CliLibIntegrationTestFixture) => Promise<void>) {
+  return withAws(withTimeout(DEFAULT_TEST_TIMEOUT_S, withCliLibIntegrationCdkApp(block)));
+}
+
+export class CliLibIntegrationTestFixture extends TestFixture {
+  /**
+   *
+   */
+  public async cdk(args: string[], options: CdkCliOptions = {}) {
+    const action = args[0];
+    const stackName = args[1];
+
+    const cliOpts: Record<string, any> = {
+      stacks: stackName ? [stackName] : undefined,
+    };
+
+    if (action === 'deploy') {
+      cliOpts.requireApproval = options.neverRequireApproval ? 'never' : 'broadening';
+    }
+
+    return this.shell(['node', '--input-type=module', `<<__EOS__
+      import { AwsCdkCli } from '@aws-cdk/cli-lib-alpha';
+      const cli = AwsCdkCli.fromCdkAppDirectory();
+
+      await cli.${action}(${JSON.stringify(cliOpts)});
+__EOS__`], {
+      ...options,
+      modEnv: {
+        AWS_REGION: this.aws.region,
+        AWS_DEFAULT_REGION: this.aws.region,
+        STACK_NAME_PREFIX: this.stackNamePrefix,
+        PACKAGE_LAYOUT_VERSION: this.packages.majorVersion(),
+        ...options.modEnv,
+      },
+    });
+  }
+
+}

packages/@aws-cdk-testing/cli-integ/resources/cdk-apps/app/app.js

@@ -403,6 +403,8 @@ class BuiltinLambdaStack extends cdk.Stack {
   }
 }
 
+class StackWithNoResources extends cdk.Stack {}
+
 const app = new cdk.App({
   context: {
     '@aws-cdk/core:assetHashSalt': process.env.CODEBUILD_BUILD_ID, // Force all assets to be unique, but consistent in one build
@@ -492,6 +494,10 @@ switch (stackSet) {
     stage.synth({ validateOnSynthesis: true });
     break;
 
+  case 'stage-with-no-resources':
+    new StackWithNoResources(app, `${stackPrefix}-stage-with-no-resources`);
+    break;
+
   default:
     throw new Error(`Unrecognized INTEG_STACK_SET: '${stackSet}'`);
 }

packages/@aws-cdk-testing/cli-integ/resources/cdk-apps/no-stack-app/app.js

@@ -0,0 +1,11 @@
+const cdk = require('aws-cdk-lib/core');
+
+const stackPrefix = process.env.STACK_NAME_PREFIX;
+if (!stackPrefix) {
+  throw new Error(`the STACK_NAME_PREFIX environment variable is required`);
+}
+
+const app = new cdk.App();
+new NoStackApp(app, `${stackPrefix}-no-stack-1`);
+
+app.synth();

packages/@aws-cdk-testing/cli-integ/resources/cdk-apps/no-stack-app/cdk.json

@@ -0,0 +1,7 @@
+{
+  "app": "node app.js",
+  "versionReporting": false,
+  "context": {
+    "aws-cdk:enableDiffNoFail": "true"
+  }
+}

packages/@aws-cdk-testing/cli-integ/tests/cli-integ-tests/cli-lib.integtest.ts

@@ -47,6 +47,28 @@ integTest('cli-lib deploy', withCliLibFixture(async (fixture) => {
   }
 }));
 
+integTest('cli-lib deploy no stack', withCliLibFixture(async (fixture) => {
+  const stackName = fixture.fullStackName('no-stack-1');
+
+  try {
+    // deploy the stack
+    await fixture.cdk(['deploy', stackName], {
+      options: ['--ignore-no-stacks'],
+    });
+
+    // verify the number of resources in the stack
+    const expectedStack = await fixture.aws.cloudFormation('describeStackResources', {
+      StackName: stackName,
+    });
+    expect(expectedStack.StackResources?.length).toEqual(0);
+  } finally {
+    // delete the stack
+    await fixture.cdk(['destroy', stackName], {
+      captureStderr: false,
+    });
+  }
+}));
+
 integTest('security related changes without a CLI are expected to fail when approval is required', withCliLibFixture(async (fixture) => {
   const stdErr = await fixture.cdk(['deploy', fixture.fullStackName('simple-1')], {
     onlyStderr: true,

packages/@aws-cdk-testing/cli-integ/tests/cli-integ-tests/cli.integtest.ts

@@ -780,6 +780,31 @@ integTest('deploy stack without resource', withDefaultFixture(async (fixture) =>
     .rejects.toThrow('conditional-resource does not exist');
 }));
 
+integTest('deploy --ignore-no-stacks', withDefaultFixture(async (fixture) => {
+  const stackArn = await fixture.cdkDeploy('stage-with-no-resources', {
+    options: ['--ignore-no-stacks'],
+    modEnv: {
+      INTEG_STACK_SET: 'stage-with-no-resources',
+    },
+  });
+
+  // verify that we only deployed both stacks (there are 2 ARNs in the output)
+  /* eslint-disable no-console */
+  console.log(stackArn);
+}));
+
+integTest('deploy stack with no resources and no --ignore-no-stacks', withDefaultFixture(async (fixture) => {
+  const stackArn = await fixture.cdkDeploy('stage-with-no-resources', {
+    modEnv: {
+      INTEG_STACK_SET: 'stage-with-no-resources',
+    },
+  });
+
+  // verify that we only deployed both stacks (there are 2 ARNs in the output)
+  /* eslint-disable no-console */
+  console.log(stackArn);
+}));
+
 integTest('IAM diff', withDefaultFixture(async (fixture) => {
   const output = await fixture.cdk(['diff', fixture.fullStackName('iam-test')]);
 

packages/aws-cdk/README.md

@@ -382,6 +382,20 @@ $ cdk deploy --method=prepare-change-set --change-set-name MyChangeSetName
 For more control over when stack changes are deployed, the CDK can generate a
 CloudFormation change set but not execute it.
 
+#### Ignore No Stacks
+
+You may have an app with multiple environments, e.g., dev and prod. When starting
+development, your prod app may not have any resources or the resources are commented
+out. In this scenario, you will receive an error message stating that the app has no
+stacks.
+
+To bypass this error messages, you can pass the `--ignore-no-stacks` flag to the 
+`deploy` command:
+
+```console
+$ cdk deploy --ignore-no-stacks
+```
+
 #### Hotswap deployments for faster development
 
 You can pass the `--hotswap` flag to the `deploy` command:

packages/aws-cdk/lib/api/cxapp/cloud-assembly.ts

@@ -106,8 +106,12 @@ export class CloudAssembly {
     const allTopLevel = selector.allTopLevel ?? false;
     const patterns = sanitizePatterns(selector.patterns);
 
-    if (stacks.length === 0 && !options.ignoreNoStacks) {
-      throw new Error('This app contains no stacks');
+    if (stacks.length === 0) {
+      if (options.ignoreNoStacks) {
+        return new StackCollection(this, []);
+      } else {
+        throw new Error('This app contains no stacks');
+      }
     }
 
     if (allTopLevel) {

packages/aws-cdk/test/api/cloud-assembly.test.ts

@@ -156,6 +156,38 @@ test('select behavior with nested assemblies: repeat', async() => {
   expect(x.stackCount).toBe(2);
 });
 
+test('select behavior with no stacks and ignore stacks option', async() => {
+  // GIVEN
+  const cxasm = await testCloudAssemblyNoStacks();
+
+  // WHEN
+  const x = await cxasm.selectStacks({ patterns: [] }, {
+    defaultBehavior: DefaultSelection.AllStacks,
+    ignoreNoStacks: true,
+  });
+
+  // THEN
+  expect(x.stackCount).toBe(0);
+});
+
+test('select behavior with no stacks and no ignore stacks option', async() => {
+  // GIVEN
+  const cxasm = await testCloudAssemblyNoStacks();
+
+  // WHEN & THEN
+  await expect(cxasm.selectStacks({ patterns: [] }, { defaultBehavior: DefaultSelection.AllStacks, ignoreNoStacks: false }))
+    .rejects.toThrow('This app contains no stacks');
+});
+
+test('select behavior with no stacks and default ignore stacks options (false)', async() => {
+  // GIVEN
+  const cxasm = await testCloudAssemblyNoStacks();
+
+  // WHEN & THEN
+  await expect(cxasm.selectStacks({ patterns: [] }, { defaultBehavior: DefaultSelection.AllStacks }))
+    .rejects.toThrow('This app contains no stacks');
+});
+
 async function testCloudAssembly({ env }: { env?: string, versionReporting?: boolean } = {}) {
   const cloudExec = new MockCloudExecutable({
     stacks: [{