Output and Errors

Render output§

.mmd and .mermaid sources replace their suffix with .svg:

flow.mmd      -> flow.svg
flow.mermaid  -> flow.svg

Other names keep their extension:

flow.txt      -> flow.txt.svg

Without --out-dir, the SVG is written beside the source. With --out-dir, every SVG is written into that directory. In ASCII mode, output goes to standard output instead.

Markdown output§

ondine markdown writes only Markdown files. Directory inputs preserve their relative structure under --out-dir.

A file with a failing Mermaid fence is not written. Other input files are still processed, and the command exits with status 1.

Diagnostics§

Compiler errors use this format:

source:line:column: message

Errors without a position use:

source: message

For Markdown fences, line and column numbers are adjusted to the Markdown file. The opening fence line is the reference for the diagram source.

--check failures§

When generated Markdown is missing or stale, --check prints:

path/to/output.md is out of date

It writes nothing and exits with status 1.

Exit status§

The command exits with status 1 when any file fails to render or when --check finds stale output. It exits with status 0 when every requested operation succeeds.

Unclosed fences and non-Mermaid fences are copied unchanged, not reported as errors.

Compiler revision§

The compiler crate is pinned to a commit in wevm/ondine rather than a crates.io release. Update the rev in Cargo.toml deliberately, then run the test suite.

Ondine CLI makes no network requests. The release binary needs no Node.js, npm, or WebAssembly runtime.