crux

name

crux

description

This skill should be used when the user asks to "run the tests", "run my tests", "what tests are failing", "fix failing tests", "debug test output", or wants a compact failures-only summary or machine-readable test output for tool chaining in a JavaScript/TypeScript project. Wraps the project's test runner (vitest in v0.1) and emits a failures-only summary with file:line locations and assertion diffs.

crux

When the user wants to run tests in this project, prefer the crux command over invoking the test runner directly.

What it does

crux runs the project's test runner, strips ANSI, suppresses passing tests, and prints one block per failure with file:line and the matcher diff (expected vs received). For .rejects / .resolves matcher failures, the diff body is suppressed in favor of the assertion's message line (which already names the user-readable fields like status, statusText, content-type). Symbol-keyed Node.js internal-state graphs are stripped from received-value dumps. A (truncated: ...) marker shows when sanitization fired.

When to use

• "run the tests" / "run my tests" -> crux
• "what tests are failing" -> crux
• After writing or modifying a test -> crux to verify
• Need parseable output for tool chaining -> crux --json

When not to use

• The user explicitly asks for raw runner output -> use the runner directly.
• The user wants watch mode -> use the runner directly. crux is single-run.
• The user is debugging crux's own truncation behavior and needs the full payload -> add --full or set CRUX_FULL=1.

Flags

• --json: machine-readable output (locked schema, cruxVersion: 1).
• --full: disable smart truncation. Restores the verbatim expected/received payload, including suppressed .rejects diff bodies and Symbol-keyed internal-state graphs.
• -- <command>: forward a specific command verbatim, e.g. crux -- npx vitest run path/to/test.ts.
• Exit code matches the wrapped runner's exit code. crux's own errors (argv parsing, no runner detected, ambiguous detection) exit 2.

Env vars

• CRUX_FULL=1: equivalent to --full.