fix(cli): cdk list pollutes stdout with synth and dependency status lines

packages/@aws-cdk-testing/cli-integ/tests/cli-integ-tests/list/cdk-cdk-ls-ci-no-synth-time-on-stdout.integtest.ts

@@ -1,19 +1,19 @@
 import { integTest, withDefaultFixture } from '../../../lib';
 
 integTest(
-  'cdk ls --json in CI does not print synthesis time to stdout',
+  'cdk ls in CI prints only the stack listing to stdout',
   withDefaultFixture(async (fixture) => {
-    // `cdk ls --json` stdout is a machine-readable contract and is often piped (e.g. to `jq`),
-    // so it must be only the stack listing, not status lines like "✨ Synthesis time: ...".
-    const listing = await fixture.cdk(['ls', '--json'], {
+    // In CI, non-error output goes to stdout. `cdk ls` stdout must be only the stack listing,
+    // not status lines like "✨ Synthesis time: ..." or "Including dependency stacks: ...".
+    const listing = await fixture.cdk(['ls'], {
       verbose: false, // fixture defaults verbose on; turn it off so stdout is just the listing
       captureStderr: false, // capture stdout only; stderr is folded into the result by default
       modEnv: { CI: 'true' }, // CI routes non-error output to stdout (default is stderr)
     });
 
     const lines = listing.trim().split('\n').filter(line => line.length > 0);
 
-    // every line should be a stack; a synth-time line would not carry the prefix
+    // every line should be a stack; a status line would not carry the stack name prefix
     expect(lines.length).toBeGreaterThan(0);
     for (const line of lines) {
       expect(line).toContain(fixture.stackNamePrefix);

packages/aws-cdk/lib/cli/cdk-toolkit.ts

@@ -967,10 +967,10 @@ export class CdkToolkit {
   ): Promise<number> {
     this.ioHost.rewriteOnce(IO.CDK_TOOLKIT_I2901, (msg) => formatStackList(msg.data.stacks, options));
 
-    // With `--json`, stdout must stay machine-parsable, so suppress the synth-time line (I1000).
-    if (options.json) {
-      this.ioHost.once(IO.CDK_TOOLKIT_I1000, () => ({ preventDefault: true }));
-    }
+    // cdk ls stdout is the stack listing only. Suppress the info status lines synthesis emits next
+    // to it: the synth-time line (I1000) and the dependency-expansion note (I1002).
+    this.ioHost.once(IO.CDK_TOOLKIT_I1000, () => ({ preventDefault: true }));
+    this.ioHost.once(IO.CDK_TOOLKIT_I1002, () => ({ preventDefault: true }));
 
     await this.toolkit.list(this.props.cloudExecutable, {
       stacks: selectors.length > 0

packages/aws-cdk/test/cli/cdk-toolkit.test.ts

@@ -220,33 +220,23 @@ describe('list', () => {
     ]);
   });
 
-  test('with --json, suppresses the synthesis-time line so stdout stays machine-parsable', async () => {
-    // `cdk ls --json` stdout is a machine-readable contract; the "Synthesis time" line
-    // (CDK_TOOLKIT_I1000) must not be written (in CI mode non-error output goes to stdout).
-    const toolkit = defaultToolkitSetup();
-    const onceSpy = jest.spyOn(ioHost, 'once');
-
-    // WHEN
-    await toolkit.list([], { json: true });
-
-    // THEN - a one-shot suppressor for I1000 was registered that prevents default handling.
-    const i1000Call = onceSpy.mock.calls.find(([code]) => (code as any)?.code === 'CDK_TOOLKIT_I1000');
-    expect(i1000Call).toBeDefined();
-    const listener = i1000Call![1] as (msg: any) => any;
-    expect(listener({ code: 'CDK_TOOLKIT_I1000' })).toEqual({ preventDefault: true });
-  });
-
-  test('without --json, does not suppress the synthesis-time line', async () => {
-    // Plain `cdk ls` is not a machine-readable contract, so the line is left alone.
+  test('suppresses the synth-time (I1000) and dependency-expansion (I1002) lines on the list path', async () => {
+    // Both are info-level lines emitted next to the listing; in CI they would land on stdout and
+    // pollute the parseable output. The list path registers a one-shot suppressor for each so they
+    // are dropped before being written. (End-to-end stdout behavior is covered by the integ test.)
     const toolkit = defaultToolkitSetup();
     const onceSpy = jest.spyOn(ioHost, 'once');
 
     // WHEN
     await toolkit.list([]);
 
     // THEN
-    const i1000Call = onceSpy.mock.calls.find(([code]) => (code as any)?.code === 'CDK_TOOLKIT_I1000');
-    expect(i1000Call).toBeUndefined();
+    for (const code of ['CDK_TOOLKIT_I1000', 'CDK_TOOLKIT_I1002']) {
+      const call = onceSpy.mock.calls.find(([sel]) => (sel as any)?.code === code);
+      expect(call).toBeDefined();
+      const listener = call![1] as (msg: any) => any;
+      expect(listener({ code })).toEqual({ preventDefault: true });
+    }
   });
 });
 

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_fails_when_stacks_have_a_circular_dependency.ndjson

@@ -1,4 +1,3 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_lists_a_multi-level_dependency_chain_in_order.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n- id: Test-Stack-C\n  dependencies:\n    - id: Test-Stack-B\n      dependencies:\n        - id: Test-Stack-A\n          dependencies: []\n"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n- id: Test-Stack-C\n  dependencies:\n    - id: Test-Stack-B\n      dependencies:\n        - id: Test-Stack-A\n          dependencies: []\n"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_lists_full_stack_details_with_--long.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  name: Test-Stack-A\n  environment:\n    account: \"123456789012\"\n    region: bermuda-triangle-1\n    name: aws://123456789012/bermuda-triangle-1\n- id: Test-Stack-B\n  name: Test-Stack-B\n  environment:\n    account: \"123456789012\"\n    region: bermuda-triangle-1\n    name: aws://123456789012/bermuda-triangle-1\n"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  name: Test-Stack-A\n  environment:\n    account: \"123456789012\"\n    region: bermuda-triangle-1\n    name: aws://123456789012/bermuda-triangle-1\n- id: Test-Stack-B\n  name: Test-Stack-B\n  environment:\n    account: \"123456789012\"\n    region: bermuda-triangle-1\n    name: aws://123456789012/bermuda-triangle-1\n"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_lists_the_selected_stacks.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"Test-Stack-A\nTest-Stack-B"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"Test-Stack-A\nTest-Stack-B"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_orders_cross-stack_references_by_dependency.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-C\n  dependencies: []\n- id: Test-Stack-A\n  dependencies:\n    - id: Test-Stack-C\n      dependencies: []\n"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-C\n  dependencies: []\n- id: Test-Stack-A\n  dependencies:\n    - id: Test-Stack-C\n      dependencies: []\n"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_shows_nested_dependencies_addressed_by_display_name.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-A/Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n- id: Test-Stack-A/Test-Stack-B/Test-Stack-C\n  dependencies:\n    - id: Test-Stack-A/Test-Stack-B\n      dependencies:\n        - id: Test-Stack-A\n          dependencies: []\n"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-A/Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n- id: Test-Stack-A/Test-Stack-B/Test-Stack-C\n  dependencies:\n    - id: Test-Stack-A/Test-Stack-B\n      dependencies:\n        - id: Test-Stack-A\n          dependencies: []\n"}

packages/aws-cdk/test/commands/__io_snapshots__/list/cdk_list_shows_the_dependencies_between_stacks.ndjson

@@ -1,5 +1,4 @@
 {"seq":0,"type":"notify","action":"list","level":"trace","code":"CDK_TOOLKIT_I1001","message":"Starting Synthesis ..."}
 {"seq":1,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1000","message":"Starting Synthesis ..."}
 {"seq":2,"type":"notify","action":"list","level":"trace","code":"CDK_CLI_I1001","message":"\n✨  Synthesis time: <DURATION>\n"}
-{"seq":3,"type":"notify","action":"list","level":"info","code":"CDK_TOOLKIT_I1000","message":"✨  Synthesis time: <DURATION>"}
-{"seq":4,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n"}
+{"seq":3,"type":"notify","action":"list","level":"result","code":"CDK_TOOLKIT_I2901","message":"- id: Test-Stack-A\n  dependencies: []\n- id: Test-Stack-B\n  dependencies:\n    - id: Test-Stack-A\n      dependencies: []\n"}