Run Tests

Running Dada Tests

Commands

# Run all tests
cargo dada test --porcelain

# Run tests in a directory
cargo dada test --porcelain tests/syntax/string_literals/

# Run a single test file
cargo dada test --porcelain tests/syntax/string_literals/type.dada

Always use --porcelain for machine-readable JSON output with structured failure information.

Interpreting Output

The --porcelain flag produces JSON with this structure:

{
  "summary": { "total": 45, "passed": 45, "failed": 0, "duration_ms": 70 },
  "tests": [
    {
      "path": "tests/syntax/string_literals/type.dada",
      "status": "pass",
      "annotations": ["#:skip_codegen", "#:spec syntax.string-literals.type"]
    }
  ]
}

For failures, each test includes:

• suggestion — Actionable guidance on how to resolve the failure. Read this first.
• details — Usually points to a .test-report.md file alongside the test

Reading Test Reports

When a test fails, a .test-report.md file is generated next to the test file. It contains:

1. Compiler output — The actual errors/warnings produced
2. Unexpected diagnostics — Errors the compiler produced that the test didn't expect
3. Missing expected diagnostics — #! annotations that didn't match any compiler output
4. Probe failures — #? probes that got unexpected results
5. Next Steps — Suggestions for resolution

Test Annotation Reference

Spec references

#:spec syntax.string-literals.escape-sequences.backslash

Links the test to a spec paragraph. Validated against actual spec files.

Directives

#:skip_codegen    # Skip WebAssembly generation (use for parser/type-check only tests)
#:fn_asts         # Compare function AST output against .ref file

Diagnostic expectations (#!)

Without carets — error can start anywhere on the previous interesting line:

print(unknown_var)
#! could not find anything named `unknown_var`

With carets — error span must match exactly (caret position = column on previous line):

fn test() { bad_name() }
#!          ^^^^^^^^ could not find anything named `bad_name`

With regex — use / prefix (opening / only, NO closing /):

is_shared(x.mut)
#! /where clause.*not satisfied

Important: The regex convention uses /pattern with NO closing /. Including a closing / causes the / to be part of the regex pattern, which will fail to match.

Type probes (#?)

let x = 22 + 44
#?      ^^ ExprType: u32       # Type of expression at that span
#?  ^ VariableType: u32        # Type of the variable

Caret position must align with the target on the previous line. VariableType shows the declared type (e.g., String not my String — the permission is on the expression, not the variable).

Probes also support regex with /:

#?  ^ VariableType: /my.*String

Common Patterns

• Tests that only exercise parsing/type-checking should use #:skip_codegen
• Error tests use #! annotations; the test passes when all expected errors match and no unexpected errors appear
• Probe tests use #? annotations; the test passes when all probes return expected values