Eric Traut 44fe510ce3 Expand native Mermaid flowchart syntax support (#48895) ...

## What changed

- Default `flowchart` and `graph` to top-down layout when no direction is specified.
- Support solid and dashed edges with directed, undirected, or bidirectional endpoints: `-->`, `---`, `<-->`, `-.->`, `-.-`, and `<-.->`.
- Accept pipe labels on these edges and spaced directed infix labels such as `A -- send --> B` and `A -. retry .-> B`.
- Expand `&` groups into all source-to-target edges, including in chains. For example, `A & B --> C & D` creates four edges. Enforce the 24-edge limit after expansion and cap each group at 24 node references.

## Testing

Add coverage for equivalent syntax, edge styles and endpoints, malformed input, and expansion limits. Extend rendering snapshots across all four directions and the TUI native-renderer test with the new syntax.

GitOrigin-RevId: 6e51653ebf6b8b7e7e1edec0c2e09a5d9c8dec74

2026-09-28 06:30:53 +00:00

..

snapshots

Expand native Mermaid flowchart syntax support (#48895)

2026-09-28 06:30:53 +00:00

draw.rs

Support stadium nodes in Mermaid terminal diagrams (#46856)

2026-09-20 17:36:48 +00:00

families_tests.rs

Expand native Mermaid flowchart syntax support (#48895)

2026-09-28 06:30:53 +00:00

lib.rs

Preserve punctuation and semicolons in Mermaid labels (#48814)

2026-09-27 23:41:04 +00:00

output.rs

Add a bounded Mermaid text renderer (#45817)

2026-09-16 00:38:34 +00:00

parse.rs

Expand native Mermaid flowchart syntax support (#48895)

2026-09-28 06:30:53 +00:00

relations.rs

Preserve punctuation and semicolons in Mermaid labels (#48814)

2026-09-27 23:41:04 +00:00

sequence.rs

Add a bounded Mermaid text renderer (#45817)

2026-09-16 00:38:34 +00:00

state.rs

Fix Mermaid shape, relationship, and state description parsing (#48489)

2026-09-26 17:26:07 +00:00

syntax.rs

Preserve punctuation and semicolons in Mermaid labels (#48814)

2026-09-27 23:41:04 +00:00

tests.rs

Expand native Mermaid flowchart syntax support (#48895)

2026-09-28 06:30:53 +00:00