Grader: output-matches

Taxonomy

Property	Value
Determinism	static
Cost	free
Portability	t1-universal
Reference	reference-free
Temporal scope	trajectory-level
Score kind	code

Config

graders:
  - type: output-matches
    config:
      pattern: "function\\s+\\w+\\("

Field	Type	Required	Description
pattern	string	Yes	Regular expression pattern to match against output
negate	boolean	No	When true, passes when the pattern does NOT match

Negated variant

Use output-not-matches as a shorthand for negate: true:

graders:
  - type: output-not-matches
    config:
      pattern: "(?i)error|exception"

This is equivalent to type: output-matches with negate: true.

Behavior

Constructs a RegExp from the pattern and tests it against trajectory.output.

Inline flags: Use the (?flags) prefix syntax to set regex flags:

• (?i)pattern — case-insensitive matching
• (?m)pattern — multiline (^/$ match line start/end)
• (?s)pattern — dotAll (. matches newlines)
• (?ims)pattern — combine multiple flags

graders:
  - type: output-matches
    config:
      pattern: "(?i)function\\s+\\w+\\(" # case-insensitive

Passes when the pattern matches (or does NOT match if negated). Fails otherwise.

Evidence examples

✔ Output matches pattern /function\s+\w+\(/
✘ Output does not match pattern /function\s+\w+\(/