Grader: file-matches

Taxonomy

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

Config

graders:
  - type: file-matches
    config:
      path: "**/Program.cs"
      pattern: "static\\s+\\w+\\s+Add\\("

Field	Type	Required	Description
path	string	Yes	Glob pattern to select files in the workspace
pattern	string	Yes	JavaScript regex pattern to match against file content
negate	boolean	No	When true, passes when the pattern does NOT match any file

Negated variant

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

graders:
  - type: file-not-matches
    config:
      path: "**/Program.cs"
      pattern: "null!"

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

Behavior

1. Finds files matching path in the workspace using glob
2. Validates the regex pattern (fails immediately if invalid)
3. Reads each matching file as UTF-8
4. Tests file content against the regex

Passes when the pattern matches at least one file’s content (or NO files match if negated). Fails otherwise.

Regex flags

Use the (?flags) prefix syntax for inline regex flags:

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

graders:
  - type: file-matches
    config:
      path: "**/*.cs"
      pattern: "(?i)public static void main"

Unreadable files

If a matching file can’t be read (EACCES, EISDIR, etc.), it is skipped and noted in the evidence string. This handles agent workspaces that may contain build artifacts or directories matching a broad glob. Binary files are NOT skipped — readFile("utf-8") returns mojibake for binary content, which simply won’t match most patterns.

Evidence examples

✔ Pattern /static\s+Add/ matched in Program.cs
✘ Pattern /static\s+Add/ not found in any file matching '**/Program.cs'
✘ No files matching '**/Program.cs' found
✘ Invalid regex pattern: [bad. Error: Unterminated character class
✔ Pattern /Add/ matched in b.cs (skipped 1 unreadable file: obj/Debug/app.dll)