Package Exports

@typesugar/ts-plugin
@typesugar/ts-plugin/dist/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@typesugar/ts-plugin) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

@typesugar/ts-plugin

TypeScript Language Service Plugin for typesugar that enables full IDE support including:

Type-aware transformation — Custom syntax (|>, ::, F<_>) and macros are transformed before TypeScript processes the code
Accurate diagnostics — Error positions map back to your original source
Go-to-definition — Navigate to original source locations, not transformed code
Completions — IntelliSense works on both original and generated code
Hover info — See type information for original symbols
Find references — Find all references to symbols across transformed code

Installation

npm install @typesugar/ts-plugin --save-dev
# or
pnpm add -D @typesugar/ts-plugin

Configuration

Add the plugin to your tsconfig.json:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "@typesugar/ts-plugin",
        "verbose": false,
        "extensions": ["hkt", "pipeline", "cons"]
      }
    ]
  }
}

Options

Option	Type	Default	Description
`verbose`	`boolean`	`false`	Enable verbose logging for debugging
`extensions`	`string[]`	`["hkt", "pipeline", "cons"]`	Syntax extensions to enable
`legacyMode`	`boolean`	`false`	Use legacy error-suppression mode instead of full transformation

Extensions

hkt — Higher-kinded type syntax (F<_> → Kind<F, A>)
pipeline — Pipe operator (a |> f → f(a))
cons — Cons operator (x :: xs → cons(x, xs))

Legacy Mode

If you encounter issues with the transform-first approach, you can fall back to legacy mode which simply suppresses errors for typesugar syntax:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "@typesugar/ts-plugin",
        "legacyMode": true
      }
    ]
  }
}

Legacy mode is less accurate but more stable. It's recommended as a fallback if you experience problems with the default mode.

VS Code Integration

When using the typesugar VS Code extension, you can configure the plugin via VS Code settings:

{
  "typesugar.useLegacyPlugin": false,
  "typesugar.enableVerboseLogging": false
}

The extension also provides commands for debugging:

typesugar: Show Transformed Source — View the transformed code in a diff view

Debugging

If you encounter issues:

Enable verbose logging to see plugin activity
Use "Show Transformed Source" to see what TypeScript is actually processing
Check the TypeScript server log for errors (VS Code: "TypeScript: Open TS Server Log")
Try legacy mode if the transform-first approach causes problems

Architecture

This plugin uses a transform-first architecture:

Preprocessing — Custom syntax is converted to valid TypeScript
Macro expansion — Macros (@derive, comptime, etc.) are expanded
Source mapping — A source map tracks the transformation
Position mapping — IDE features map positions back to original source

The same transformation pipeline is used by:

Build tools (via unplugin-typesugar)
CLI (via @typesugar/transformer)
This language service plugin

This ensures consistent behavior across all tools.