Plugin structure

Partas.Solid ships as two NuGet packages that always share a version:

• Partas.Solid is the DSL: tags, attributes, the style spec and the Solid bindings. Almost all of it is erased or imported. The types exist to give you a typed way to write components, and the plugin erases them.
• Partas.Solid.FablePlugin is a Fable compiler plugin that rewrites the F# AST into JSX. This is where the behaviour lives. Without it, the library produces nothing useful.

Because the plugin rewrites the AST rather than running anything at runtime, the JSX it writes is the specification. You see a change in behaviour by comparing the generated JSX. See Contributing for how the snapshot tests do that.

Files

The plugin project targets net6.0 and references Fable.AST 5.0. Its files compile in this order, and each one depends only on the ones before it:

Partas.Solid.FablePlugin
|-- Utils.fs       # string and AST active patterns, AST and JSX constructors
|-- Types.fs       # PluginContext, ComponentFlag, IdentType and the other plugin types
|-- Spec.fs        # what input is legal, prebaked expressions, recognisers for AST nodes
|-- Plugin.fs      # the transformation tree and the two public attributes
|__ Storybook.fs   # a separate attribute that writes Storybook CSF output

Storybook.fs holds PartasStorybookAttribute, which turns a story definition into a Storybook CSF module. It has its own recursion over the story type, and is covered in Storybook.

Rules for the plugin project

• Warnings 3239 and 0025 (incomplete pattern matches) are errors. An inexhaustive match in the plugin fails the build.
• Plugin.fs is excluded from fantomas. Do not format it.
• The plugin requires Fable 5 and only runs when the target is JavaScript and the file extension is .js or .jsx. The docs and tests compile with -e .fs.jsx.