Type generation with WIT folder support (#426)

Author: guybedford

crates/js-component-bindgen-component/src/lib.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use anyhow::Result;
+use anyhow::{Context, Result};
 use js_component_bindgen::{
     generate_types,
     source::wit_parser::{Resolve, UnresolvedPackage},
@@ -117,17 +117,30 @@ impl Guest for JsComponentBindgenComponent {
         opts: TypeGenerationOptions,
     ) -> Result<Vec<(String, Vec<u8>)>, String> {
         let mut resolve = Resolve::default();
-        let pkg = match opts.wit {
+        let id = match opts.wit {
             Wit::Source(source) => {
-                UnresolvedPackage::parse(&PathBuf::from(format!("{name}.wit")), &source)
-                    .map_err(|e| e.to_string())?
+                let pkg = UnresolvedPackage::parse(&PathBuf::from(format!("{name}.wit")), &source)
+                    .map_err(|e| e.to_string())?;
+                resolve.push(pkg).map_err(|e| e.to_string())?
             }
             Wit::Path(path) => {
-                UnresolvedPackage::parse_file(&PathBuf::from(path)).map_err(|e| e.to_string())?
+                let path = PathBuf::from(path);
+                if path.is_dir() {
+                    resolve.push_dir(&path).map_err(|e| e.to_string())?.0
+                } else {
+                    let contents = std::fs::read(&path)
+                        .with_context(|| format!("failed to read file {path:?}"))
+                        .map_err(|e| e.to_string())?;
+                    let text = match std::str::from_utf8(&contents) {
+                        Ok(s) => s,
+                        Err(_) => return Err("input file is not valid utf-8".into()),
+                    };
+                    let pkg = UnresolvedPackage::parse(&path, text).map_err(|e| e.to_string())?;
+                    resolve.push(pkg).map_err(|e| e.to_string())?
+                }
             }
             Wit::Binary(_) => todo!(),
         };
-        let id = resolve.push(pkg).map_err(|e| e.to_string())?;
 
         let world_string = opts.world.map(|world| world.to_string());
         let world = resolve

src/api.js

@@ -1,5 +1,5 @@
 export { optimizeComponent as opt } from './cmd/opt.js';
-export { transpileComponent as transpile } from './cmd/transpile.js';
+export { transpileComponent as transpile, typesComponent as types } from './cmd/transpile.js';
 import { $init, tools } from "../obj/wasm-tools.js";
 const { print: printFn, parse: parseFn, componentWit: componentWitFn, componentNew: componentNewFn, componentEmbed: componentEmbedFn, metadataAdd: metadataAddFn, metadataShow: metadataShowFn } = tools;
 

src/cmd/transpile.js

@@ -1,4 +1,4 @@
-import { $init, generate } from '../../obj/js-component-bindgen-component.js';
+import { $init, generate, generateTypes } from '../../obj/js-component-bindgen-component.js';
 import { writeFile } from 'node:fs/promises';
 import { mkdir } from 'node:fs/promises';
 import { dirname, extname, basename, resolve } from 'node:path';
@@ -14,6 +14,58 @@ import { platform } from 'node:process';
 
 const isWindows = platform === 'win32';
 
+export async function types (witPath, opts) {
+  const files = await typesComponent(witPath, opts);
+  await writeFiles(files, opts.quiet ? false : 'Generated Type Files');
+}
+
+/**
+ * @param {string} witPath
+ * @param {{
+ *   name?: string,
+ *   worldName?: string,
+ *   instantiation?: 'async' | 'sync',
+ *   tlaCompat?: bool,
+ *   outDir?: string,
+ * }} opts
+ * @returns {Promise<{ [filename: string]: Uint8Array }>}
+ */
+export async function typesComponent (witPath, opts) {
+  await $init;
+  const name = opts.name || (opts.worldName
+    ? opts.worldName.split(':').pop().split('/').pop()
+    : basename(witPath.slice(0, -extname(witPath).length || Infinity)));
+  let instantiation;
+  if (opts.instantiation) {
+    instantiation = { tag: opts.instantiation };
+  }
+  let outDir = (opts.outDir ?? '').replace(/\\/g, '/');
+  if (!outDir.endsWith('/') && outDir !== '')
+    outDir += '/';
+  return Object.fromEntries(generateTypes(name, {
+    wit: { tag: 'path', val: (isWindows ? '//?/' : '') + resolve(witPath) },
+    instantiation,
+    tlaCompat: opts.tlaCompat ?? false,
+    world: opts.worldName
+  }).map(([name, file]) => [`${outDir}${name}`, file]));
+}
+
+async function writeFiles(files, summaryTitle) {
+  await Promise.all(Object.entries(files).map(async ([name, file]) => {
+    await mkdir(dirname(name), { recursive: true });
+    await writeFile(name, file);
+  }));
+  if (!summaryTitle)
+    return;
+  console.log(c`
+  {bold ${summaryTitle}:}
+  
+${table(Object.entries(files).map(([name, source]) => [
+    c` - {italic ${name}}  `,
+    c`{black.italic ${sizeStr(source.length)}}`
+  ]))}`);
+}
+
 export async function transpile (componentPath, opts, program) {
   const varIdx = program?.parent.rawArgs.indexOf('--');
   if (varIdx !== undefined && varIdx !== -1)
@@ -37,20 +89,7 @@ export async function transpile (componentPath, opts, program) {
   if (opts.map)
     opts.map = Object.fromEntries(opts.map.map(mapping => mapping.split('=')));
   const { files } = await transpileComponent(component, opts);
-
-  await Promise.all(Object.entries(files).map(async ([name, file]) => {
-    await mkdir(dirname(name), { recursive: true });
-    await writeFile(name, file);
-  }));
-
-  if (!opts.quiet)
-    console.log(c`
-{bold Transpiled JS Component Files:}
-
-${table(Object.entries(files).map(([name, source]) => [
-  c` - {italic ${name}}  `,
-  c`{black.italic ${sizeStr(source.length)}}`
-]))}`);
+  await writeFiles(files, opts.quiet ? false : 'Transpiled JS Component Files');
 }
 
 let WASM_2_JS;
@@ -91,6 +130,7 @@ async function wasm2Js (source) {
  *   minify?: bool,
  *   optimize?: bool,
  *   namespacedExports?: bool,
+ *   outDir?: string,
  *   multiMemory?: bool,
  *   optArgs?: string[],
  * }} opts

src/jco.js

@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 import { program, Option } from 'commander';
 import { opt } from './cmd/opt.js';
-import { transpile } from './cmd/transpile.js';
+import { transpile, types } from './cmd/transpile.js';
 import { run as runCmd, serve as serveCmd } from './cmd/run.js';
 import { parse, print, componentNew, componentEmbed, metadataAdd, metadataShow, componentWit } from './cmd/wasm-tools.js';
 import { componentize } from './cmd/componentize.js';
@@ -48,12 +48,24 @@ program.command('transpile')
   .option('--stub', 'generate a stub implementation from a WIT file directly')
   .option('--js', 'output JS instead of core WebAssembly')
   .addOption(new Option('-I, --instantiation [mode]', 'output for custom module instantiation').choices(['async', 'sync']).preset('async'))
-  .option('-q, --quiet', 'disable logging')
+  .option('-q, --quiet', 'disable output summary')
   .option('--no-namespaced-exports', 'disable namespaced exports for typescript compatibility')
   .option('--multi-memory', 'optimized output for Wasm multi-memory')
   .option('--', 'for --optimize, custom wasm-opt arguments (defaults to best size optimization)')
   .action(asyncAction(transpile));
 
+program.command('types')
+  .description('Generate types for the given WIT')
+  .usage('<wit-path> -o <out-dir>')
+  .argument('<wit-path>', 'path to a WIT file or directory')
+  .option('--name <name>', 'custom output name')
+  .option('-n, --world-name <world>', 'WIT world to generate types for')
+  .requiredOption('-o, --out-dir <out-dir>', 'output directory')
+  .option('--tla-compat', 'generates types for the TLA compat output with an async $init promise export')
+  .addOption(new Option('-I, --instantiation [mode]', 'type output for custom module instantiation').choices(['async', 'sync']).preset('async'))
+  .option('-q, --quiet', 'disable output summary')
+  .action(asyncAction(types));
+
 program.command('run')
   .description('Run a WASI Command component')
   .usage('<command.wasm> <args...>')
@@ -158,7 +170,7 @@ program.command('embed')
   .requiredOption('--wit <wit-world>', 'WIT world path')
   .option('--dummy', 'generate a dummy component')
   .option('--string-encoding <utf8|utf16|compact-utf16>', 'set the component string encoding')
-  .option('--world <world-name>', 'positional world path to embed')
+  .option('-n, --world-name <world-name>', 'world name to embed')
   .option('-m, --metadata <metadata...>', 'field=name[@version] producer metadata to add with the embedding')
   .action(asyncAction(componentEmbed));
 

test/api.js

@@ -2,6 +2,7 @@ import { deepStrictEqual, ok, strictEqual } from "node:assert";
 import { readFile } from "node:fs/promises";
 import {
   transpile,
+  types,
   opt,
   print,
   parse,
@@ -92,6 +93,15 @@ export async function apiTest(fixtures) {
       ok(source.includes("'#testimport'"));
     });
 
+    test('Type generation', async () => {
+      const files = await types('test/fixtures/wit', {
+        worldName: 'test:flavorful/flavorful',
+      });
+     strictEqual(Object.keys(files).length, 2);
+     strictEqual(Object.keys(files)[0], 'flavorful.d.ts');
+     ok(Buffer.from(files[Object.keys(files)[0]]).includes('export const test'));
+    });
+
     test("Optimize", async () => {
       const component = await readFile(
         `test/fixtures/components/flavorful.component.wasm`

test/cli.js

@@ -180,6 +180,21 @@ export async function cliTest(fixtures) {
       );
     });
 
+    test("Type generation", async () => {
+      const { stderr } = await exec(
+        jcoPath,
+        "types",
+        "test/fixtures/wit",
+        "--world-name",
+        "test:flavorful/flavorful",
+        "-o",
+        outDir
+      );
+      strictEqual(stderr, "");
+      const source = await readFile(`${outDir}/flavorful.d.ts`, "utf8");
+      ok(source.includes("export const test"));
+    });
+
     test("TypeScript naming checks", async () => {
       const { stderr } = await exec(
         jcoPath,