dsl-visual-tests

Visual golden tests for @m0saic/dsl-stdlib.

These tests render m0 strings to wireframe PNGs and compare them against committed goldens. Each golden also has a sibling .m0 file so the underlying geometry can be inspected directly.

Purpose

• Validate geometry correctness, not styling
• Lock down layout invariants across stdlib helpers
• Provide human- and AI-readable artifacts (.png + .m0)

Structure

Tests are organized by feature area:

• grid/
• strip/
• split/
• measureSplit/
• overlay/
• edgeCases/
• replace/
• swap/

Each folder contains:

• *.goldens.test.ts
• __goldens__/ (PNG + .m0 pairs)

How it works

Each test:

1. Builds a DSL string using stdlib helpers
2. Serializes to a deterministic .m0 file (includes # size: WxH)
3. Renders a wireframe PNG via the m0saic CLI
4. Compares against the committed golden

Running tests

Verify mode (default):

npm test -- --testPathPattern dsl-visual-tests

Update goldens:

M0SAIC_UPDATE_GOLDENS=1 npm test -- --testPathPattern dsl-visual-tests

Verbose output:

M0SAIC_GOLDEN_VERBOSE=1 npm test -- --testPathPattern dsl-visual-tests

Philosophy

• PNG = visual truth
• .m0 = geometric truth
• Input string = “before”
• Golden = “after”

These tests are intentionally minimal and high-signal.
Not all helpers require visual coverage—some are better validated via unit tests.

License

Licensed under the Apache License, Version 2.0.
See LICENSE and NOTICE.