tsparser-wasm

WebAssembly build of the Encore TypeScript parser. Parses Encore.ts source files in the browser and returns application metadata (APIs, services, infrastructure resources, etc.).

Prerequisites

cargo install wasm-pack

Building

From this directory (tsparser/wasm/):

wasm-pack build --target web

This produces a pkg/ directory containing:

tsparser_wasm_bg.wasm — the compiled WebAssembly module
tsparser_wasm.js — JavaScript bindings (ES module)
tsparser_wasm.d.ts — TypeScript type declarations
package.json — ready to publish to npm or use locally

Usage

import init, { parse } from './pkg/tsparser_wasm.js';

await init();

const files = [
  // User source files
  { name: "myservice/encore.service.ts", content: `import { Service } from "encore.dev/service";\nexport default new Service("myservice");` },
  { name: "myservice/api.ts", content: `import { api } from "encore.dev/api";\nexport const ping = api({ method: "GET", path: "/ping" }, async () => { return { message: "pong" }; });` },

  // Optional: tsconfig.json for path alias support
  { name: "tsconfig.json", content: `{"compilerOptions": {"paths": {"@/*": ["./src/*"]}}}` },

  // Optional: node_modules files (package.json + .d.ts type declarations)
  { name: "node_modules/zod/package.json", content: `{"name": "zod", "exports": {".": {"types": "./lib/index.d.mts"}}}` },
  { name: "node_modules/zod/lib/index.d.mts", content: `export declare function string(): ZodString; ...` },
];

const result = JSON.parse(parse(JSON.stringify(files)));

if (result.ok) {
  console.log("Parsed metadata:", result.meta);
} else {
  console.error("Parse errors:", result.errors);
}

Input format

parse() accepts a JSON string containing an array of {name, content} objects:

File pattern	Treatment
`node_modules/**`	Registered for module resolution but not parsed as user code. `package.json` files are used for bare import resolution (`exports`, `types`, `main` fields).
`tsconfig.json`	Parsed for `compilerOptions.paths` and `baseUrl` to support path aliases. JSONC (comments) is supported.
Everything else	Parsed as user source code. Only `.ts` files are processed.

Output format

Returns a JSON string:

json

{
  "ok": true,
  "errors": [],
  "meta": { /* encore.parser.meta.v1 protobuf as JSON */ }
}

When ok is false, errors contains human-readable error messages and meta is absent.