[rush] Treat a phased command with zero operations as success

[Sean Larkin (TheLarkInn)]

Summary

Fixes #5914.

A phased command whose plugins legitimately produce no operations exits with code 1, even
though nothing failed. This breaks @rushstack/rush-buildxl-graph-plugin, so every BuildXL build
using the Rush resolver fails.

Details

OperationGraph._scheduleIterationAsync does not schedule an iteration when there are no non-silent
operations:

if (iterationContext.totalOperations === 0) {
  return;
}

so executeAsync early-returns OperationStatus.NoOp without firing any graph hooks:

const scheduled = await this._scheduleIterationAsync(iterationOptions);
if (!scheduled) {
  return { operationResults: this.resultByOperation, status: OperationStatus.NoOp };
}

and PhasedScriptAction computed:

success = definiteResult.status === OperationStatus.Success;

NoOp !== Success → success = false → AlreadyReportedError → exit 1.

DropBuildGraphPlugin writes the build graph to disk in response to --drop-graph and then returns
new Set() because there is nothing left for Rush to execute. The result is that
rush <command> --drop-graph exits 1 with no error message and a correctly-written graph file,
which BuildXL reports as DX11901 / DX11230.

Because the early return skips all graph hooks, this cannot be worked around by a plugin — there
is no hook available to observe or correct the status.

Why this is the right fix

PhasedScriptAction already treats an empty project selection as success:

if (!generateFullGraph && !projectSelection.size) {
  terminal.writeLine(Colorize.yellow(`The command line selection parameters did not match any projects.`));
  return;   // exits 0
}

So "nothing to do because no projects matched" was a success while "nothing to do because no
operations were produced" was a failure. This change makes them agree.

The completion message now keys off success rather than re-deriving the status, so a no-op
invocation is also reported in green rather than looking like a silent failure.

Changes

• PhasedScriptAction.ts — treat OperationStatus.NoOp as success; use success for the
  completion message. Removes the now-unused result local.
• New regression test in RushCommandLineParser.test.ts plus fixtures:
  • rush-mock-clear-operations-plugin/ — an in-repo plugin that taps createOperationsAsync at
    stage: Number.MAX_SAFE_INTEGER and returns an empty set, mirroring DropBuildGraphPlugin.
  • clearOperationsAndRunBuildActionRepo/ — mock repo wiring that plugin.
  • config/heft.json — copy the mock plugin into the fixture's autoinstaller, matching the
    existing rush-mock-flush-telemetry-plugin pattern.
• Change file for @microsoft/rush (patch).

Verification

Check	Result
New test without the fix	FAILS — expect(parser.executeAsync()).resolves.toEqual(true) → Received: false
New test with the fix	passes
Full rush-lib suite	721 passed, 0 failed
rush build --to @microsoft/rush-lib	clean, no lint warnings

Notes for reviewers

An alternative would be to give phased commands a supported "handled — stop here successfully"
mechanism, analogous to IGlobalCommand.setHandled(), so plugins like DropBuildGraphPlugin do not
have to signal completion by returning an empty operation set. That seemed like a larger API change
than warranted for a regression fix, but I'm happy to go that route instead.

[Copilot]

Pull request overview

This PR fixes a regression where phased commands that legitimately produce zero operations (e.g., a plugin consumes the work and returns an empty operation set) would exit with a nonzero code due to OperationStatus.NoOp being treated as failure in PhasedScriptAction. It aligns “no operations to execute” with existing behavior where “no projects matched” is considered a successful no-op.

Changes:

• Treat OperationStatus.NoOp as a success outcome for phased commands and key the completion message off the computed success flag.
• Add a regression test that wires an in-repo plugin which clears the operation set and verifies the command succeeds without spawning any tasks.
• Add test fixtures + Heft copy wiring to stage the mock plugin into the fixture autoinstaller (mirroring the existing flush-telemetry mock plugin pattern), plus a patch change file for @microsoft/rush.

Show a summary per file

File	Description
libraries/rush-lib/src/cli/scriptActions/PhasedScriptAction.ts	Treats NoOp execution status as success and uses the computed success for the final terminal status line.
libraries/rush-lib/src/cli/test/RushCommandLineParser.test.ts	Adds regression test ensuring a phased command succeeds when a plugin returns an empty operation set, and asserts no tasks were spawned.
libraries/rush-lib/src/cli/test/rush-mock-clear-operations-plugin/rush-plugin-manifest.json	Adds manifest for a mock plugin that clears operations.
libraries/rush-lib/src/cli/test/rush-mock-clear-operations-plugin/package.json	Adds package metadata for the mock plugin.
libraries/rush-lib/src/cli/test/rush-mock-clear-operations-plugin/index.ts	Implements mock plugin that taps createOperationsAsync at a very late stage and returns an empty Set<Operation>().
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/rush.json	Adds a new unit-test repo fixture for the regression scenario.
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/common/config/rush/rush-plugins.json	Configures the fixture to load the mock plugin via an autoinstaller.
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/common/autoinstallers/plugins/package.json	Defines the fixture autoinstaller dependency on the mock plugin (file: reference).
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/common/autoinstallers/plugins/rush-plugins/rush-mock-clear-operations-plugin/rush-plugin-manifest.json	Stages the plugin manifest in the fixture’s autoinstaller plugin manifest folder.
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/a/package.json	Adds fixture project “a” with build/rebuild scripts for baseline behavior.
libraries/rush-lib/src/cli/test/clearOperationsAndRunBuildActionRepo/b/package.json	Adds fixture project “b” with build/rebuild scripts for baseline behavior.
libraries/rush-lib/config/heft.json	Copies the built mock plugin output into the fixture autoinstaller node_modules location (matching the existing mock plugin pattern).
common/changes/@microsoft/rush/fix-noop-exit-code_2026-07-28-18-56-00.json	Records the patch change for @microsoft/rush.

Review details

• Files reviewed: 13/13 changed files
• Comments generated: 0
• Review effort level: Lite

[Copilot]

Review details

• Files reviewed: 13/13 changed files
• Comments generated: 1
• Review effort level: Lite