Inverse of flowchart-mermaid.js's toMermaid(). Pure module — no DOM,
no globals — so the parsing logic is unit-tested in isolation.
Recognises the 5 node shapes:
- process [label]
- decision {label}
- terminator ([label])
- subroutine [[label]]
- document [/label/]
Recognises the 3 edge arrows:
- --> solid
- -.-> dotted
- ==> thick
Edge labels may appear before OR after the arrow (Mermaid accepts
both: and ).
Behaviour:
- Auto-creates nodes referenced in edges but not declared explicitly.
- Idempotent: declaring then connecting does not
duplicate the A node.
- Defensive: malformed lines are skipped silently so partial /
hand-edited source still loads whatever it can.
- Unescapes the standard Mermaid escapes (#quot; → ", \n → newline).
Wire-up into the renderer (Open from .mmd file → parse →
store.deserialize) is the next commit; this lands the testable math.
23 new tests cover shape parsing for all 5 kinds, edge parsing for
all 3 arrow types + label placement, unescaping, header skipping,
comment skipping, the subroutine-vs-process regression, auto-node
creation, and the null/non-string inputs.
Amit Haridas
