fix(core): handle run-commands targets with no commands

[FrozenPandaz]

Current Behavior

Nx hangs when here is a run-commands target with no commands.

Expected Behavior

Nx does not hang when there is a run-commands target with no commands.

Related Issue(s)

Fixes #31345

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

1 Skipped Deployment

Name	Status	Preview	Updated (UTC)
nx-dev	⬜️ Ignored (Inspect)	Visit Preview	May 28, 2025 7:04pm

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 622b68c.

Command	Status	Duration	Result
nx affected --targets=lint,test,build,e2e,e2e-c...	✅ Succeeded	45m 41s	View ↗
nx run-many -t check-imports check-commit check...	✅ Succeeded	20s	View ↗
nx-cloud record -- nx-cloud conformance:check	✅ Succeeded	2s	View ↗
nx-cloud record -- nx format:check	✅ Succeeded	3s	View ↗
nx-cloud record -- nx sync:check	✅ Succeeded	2s	View ↗
nx documentation	✅ Succeeded	1m 53s	View ↗

---

☁️ Nx Cloud last updated this comment at 2025-05-28 19:54:35 UTC

[Copilot]

Pull Request Overview

This PR fixes an issue where Nx hangs when a run-commands target has no commands by simulating a successful process exit.

• Modify NoopChildProcess to simulate immediate task completion
• Update runCommands to return NoopChildProcess for empty commands arrays
• Add a test case to validate that an empty commands array returns a successful result

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/nx/src/tasks-runner/running-tasks/noop-child-process.ts	Introduces exitCallbacks and outputCallbacks; simulates immediate exit in the constructor
packages/nx/src/executors/run-commands/run-commands.impl.ts	Returns NoopChildProcess when commands array is empty
packages/nx/src/executors/run-commands/run-commands.impl.spec.ts	Adds test for handling empty commands arrays

[Copilot]

The 'exitCallbacks' and 'outputCallbacks' arrays are defined and iterated over in the constructor but are never updated when callbacks are registered via onExit or onOutput. Consider either removing these arrays or updating the implementation to store and later invoke registered callbacks consistently.

Suggested change

	for (const cb of this.exitCallbacks) {
	cb(this.results.code, this.results.terminalOutput);
	}
	setTimeout(() => {
	for (const cb of this.exitCallbacks) {
	cb(this.results.code, this.results.terminalOutput);
	}
	}, 0);

[Copilot]

The test expects a 'success' property on the result, but NoopChildProcess does not explicitly provide this. Consider adding a getter for 'success' (e.g., returning true when results.code equals 0) to align the implementation with the test expectations.

[graphite-app]

The constructor is attempting to iterate through exitCallbacks which is initialized as an empty array, so no callbacks will be executed at this point. Since callbacks are registered through the onExit method after construction, consider modifying onExit to either:

1. Execute the callback immediately if called after construction:

onExit(cb: (code: number, terminalOutput: string) => void): void {
  this.exitCallbacks.push(cb);
  // Already completed, call immediately
  cb(this.results.code, this.results.terminalOutput);
}

2. Or use setTimeout to ensure callbacks are executed asynchronously:

constructor(private results: { code: number; terminalOutput: string }) {
  setTimeout(() => {
    for (const cb of this.exitCallbacks) {
      cb(this.results.code, this.results.terminalOutput);
    }
  }, 0);
}

This will ensure proper simulation of an asynchronous process completion.

Suggested change

	constructor(private results: { code: number; terminalOutput: string }) {
	// Call exit callbacks asynchronously to simulate task completion
	for (const cb of this.exitCallbacks) {
	cb(this.results.code, this.results.terminalOutput);
	}
	}
	constructor(private results: { code: number; terminalOutput: string }) {
	// Defer callback execution to next event loop tick to simulate async task completion
	setTimeout(() => {
	for (const cb of this.exitCallbacks) {
	cb(this.results.code, this.results.terminalOutput);
	}
	}, 0);
	}

Spotted by Diamond

Is this helpful? React 👍 or 👎 to let us know.

[Copilot]

Pull Request Overview

This PR ensures that run-commands targets with an empty commands array return immediately instead of hanging.

• Adds a NoopChildProcess implementation that emits a zero exit code and empty output.
• Introduces an early return in runCommands when there are no commands.
• Adds a unit test to verify the empty-commands behavior.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
packages/nx/src/tasks-runner/running-tasks/noop-child-process.ts	Expanded NoopChildProcess with onExit/onOutput APIs
packages/nx/src/executors/run-commands/run-commands.impl.ts	Added early-return using NoopChildProcess for empty lists
packages/nx/src/executors/run-commands/run-commands.impl.spec.ts	Added test case for handling an empty commands array

Comments suppressed due to low confidence (1)

packages/nx/src/tasks-runner/running-tasks/noop-child-process.ts:18

• The NoopChildProcess class doesn’t expose success or terminalOutput properties, but the new test asserts them directly. Add getters to forward this.results.code === 0 as success and this.results.terminalOutput as terminalOutput.

}