Grader: file-exists

Taxonomy

Property	Value
Determinism	static
Cost	low
Reference	reference-free
Temporal scope	trajectory-level
Score kind	code

Config

graders:
  - type: file-exists
    config:
      path: "add.test.js"

Field	Type	Required	Description
path	string	Yes	File path or glob pattern to match in the workspace
negate	boolean	No	When true, passes when NO files match

Negated variant

Use file-not-exists as a shorthand for negate: true:

graders:
  - type: file-not-exists
    config:
      path: "*.tmp"

This is equivalent to type: file-exists with negate: true.

Behavior

Uses Node.js glob() to search the trajectory’s workDir for files matching the pattern.

Passes when at least one file matches (or NO files match if negated). Fails otherwise.

Supports standard glob patterns:

• "add.test.js" — exact file
• "*.test.js" — all test files
• "src/**/*.ts" — recursive TypeScript files
• "output/*.{json,txt}" — multiple extensions

Evidence examples

✔ Files matching 'add.test.js' found: add.test.js
✔ Files matching '*.test.js' found: add.test.js, utils.test.js
✘ No files matching 'add.test.js' found

Source

async grade(input: GraderInput): Promise<GraderResult> {
  await assertWorkDirAccessible(input.trajectory.workDir);

  const matchIter = glob(input.config.path, {
    withFileTypes: false,
    cwd: input.trajectory.workDir,
  });

  const matches = [];
  for await (const item of matchIter) {
    matches.push(item);
  }

  const passed = matches.length > 0;

  return {
    name: this.metadata.name,
    kind: "code",
    passed,
    score: passed ? 1 : 0,
    evidence: passed
      ? `Files matching '${input.config.path}' found: ${matches.join(", ")}`
      : `No files matching '${input.config.path}' found`,
    label: passed ? "correct" : "incorrect",
  };
}