Registry / serialization / esbuild-plugin-wat

esbuild-plugin-wat

library0.2.7jsnpmunverified

esbuild plugin (v0.2.7) for importing WebAssembly (.wasm) and WebAssembly text format (.wat) files. Resolves imports to a default Uint8Array export suitable for WebAssembly.instantiate()/compile(). Ships TypeScript types. Differentiators: supports .wat compilation via wabt.js with caching, optional binaryen inlining optimization, configurable loader (binary/base64/file), experimental bundling of multiple wat/wasm files using import syntax. Lightweight alternative to full-featured bundler plugins like wasm-pack.

serialization devops

npm install esbuild-plugin-wat

github ↗package ↗

INSTALL

IMPORT

SIG · ESBUILD-PLUGIN-WAT

esbuild-plugin-wat

serializationjavascriptv0.2.7

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import watPlugin from 'esbuild-plugin-wat'

✗ const watPlugin = require('esbuild-plugin-wat')

Package is ESM-only; default export is a function, not an object.

WatPlugin

✓ import type { WatPlugin } from 'esbuild-plugin-wat'

✗ import { WatPlugin } from 'esbuild-plugin-wat'

Type import only; WatPlugin is an interface, not a runtime value.

PluginOptions

✓ import type { PluginOptions } from 'esbuild-plugin-wat'

✗ import { PluginOptions } from 'esbuild-plugin-wat'

Type import for configuration object shape.

Demonstrates esbuild configuration with watPlugin to import .wat files as Uint8Array, showing default options and commented alternatives.

import { build } from 'esbuild'; import watPlugin from 'esbuild-plugin-wat'; await build({ entryPoints: ['src/index.js'], bundle: true, outfile: 'dist/out.js', plugins: [watPlugin({ loader: 'binary', // default: inline .wasm as binary // loader: 'file', // emit separate .wasm files inlineFunctions: false, wasmFeatures: { simd: true }, // bundle: true, // experimental bundling of wat modules })], }); // In your source: // import wasm from './example.wat'; // const module = await WebAssembly.instantiate(wasm);

Debug

Known issues

gotchaDefault export is a Uint8Array, not a compiled WebAssembly.Module. Must call WebAssembly.instantiate()/compile() explicitly.

fix

Use: const { instance } = await WebAssembly.instantiate(wasm);

affects: >=0.0.1

deprecatedSetting loader to 'file' may cause runtime fetch errors if the .wasm file path is not correctly resolved in production builds.

fix

Use 'binary' (default) to inline the binary; use 'file' only if you control the static file serving and path resolution.

affects: >=0.1.0

breakingv0.2.0 dropped support for CommonJS require. package.json type field changed to 'module'.

fix

Switch to ESM imports: import watPlugin from 'esbuild-plugin-wat'

affects: >=0.2.0

deprecatedOptions object is mutable and shared across builds; avoid reusing same config object for multiple esbuild runs.

fix

Create a fresh options object per build call: watPlugin({ ... })

affects: >=0.2.0

gotchaBundling (bundle: true) is experimental and does not support all wasm import syntaxes.

fix

Test thoroughly with your .wat files; fall back to multiple separate .wasm imports if issues arise.

affects: >=0.2.0

Errors

Common errors & fixes

Cannot find module 'esbuild-plugin-wat'

Package is ESM-only; require() fails in CJS context.

fix

Use import statement or set { "type": "module" } in package.json.

Error: esbuild plugin 'wat' must be a function or an object with a name property

Calling watPlugin incorrectly, e.g., watPlugin without parentheses.

fix

Use watPlugin() (a function call) in plugins array, not just watPlugin reference.

TypeError: WebAssembly.instantiate: first argument must be a BufferSource or WebAssembly.Module

Passing a string (e.g., base64) instead of Uint8Array to instantiate.

fix

Ensure the default export is used as-is: const wasm = await import('./file.wat'); WebAssembly.instantiate(wasm.default);

Upgrade

Version history

0.2.7latest on npm

Audit

Dependencies

esbuildrequiredpeer dependency - plugin requires esbuild to function

wabtoptionalconverts .wat to .wasm; bundled as dependency

binaryenoptionaloptional optimization for function inlining

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/mitschabaude/esbuild-plugin-wat ↗

packagehttps://www.npmjs.com/package/esbuild-plugin-wat ↗