Set up code to publish web bindings to npm

lib/binding_web/.gitignore

@@ -0,0 +1,4 @@
+/tree-sitter.js
+/tree-sitter.wasm
+node_modules
+*.tgz

lib/binding_web/.npmignore

@@ -0,0 +1,4 @@
+*
+!README.md
+!tree-sitter.js
+!tree-sitter.wasm

lib/binding_web/README.md

@@ -1,16 +1,16 @@
-tree-sitter.wasm
-================
+Web Tree-sitter
+===============
 
 [![Build Status](https://travis-ci.org/tree-sitter/tree-sitter.svg?branch=master)](https://travis-ci.org/tree-sitter/tree-sitter)
 
-Wasm bindings to the [Tree-sitter](https://github.com/tree-sitter/tree-sitter) parsing library.
+WebAssembly bindings to the [Tree-sitter](https://github.com/tree-sitter/tree-sitter) parsing library.
 
-### Basic Usage
+### Setup
 
-You can either load the library as a standalone script:
+You can download the the `tree-sitter.js` and `tree-sitter.wasm` files from [the latest GitHub release](https://github.com/tree-sitter/tree-sitter/releases/tag/0.14.7) and load them using a standalone script:
 
 ```html
-<script src="/public/js/tree-sitter.js"/>
+<script src="/the/path/to/tree-sitter.js"/>
 
 <script>
   const Parser = window.TreeSitter;
@@ -18,14 +18,16 @@ You can either load the library as a standalone script:
 </script>
 ```
 
-or using a packaging system like Webpack:
+You can also install [the `web-tree-sitter` module](https://www.npmjs.com/package/web-tree-sitter) from NPM and load it using a system like Webpack:
 
 ```js
-const Parser = require('tree-sitter');
+const Parser = require('web-tree-sitter');
 Parser.init().then(() => { /* the library is ready */ });
 ```
 
-Create a parser:
+### Basic Usage
+
+First, create a parser:
 
 ```js
 const parser = new Parser;

lib/binding_web/check-artifacts-fresh.js

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const path = require('path');
+
+const inputFiles = [
+  'binding.c',
+  'binding.js',
+  'exports.json',
+  'imports.js',
+  'prefix.js',
+  ...list('../include/tree_sitter'),
+  ...list('../src')
+]
+
+const outputFiles = [
+  'tree-sitter.js',
+  'tree-sitter.wasm',
+]
+
+const outputMtime = Math.min(...outputFiles.map(mtime));
+
+for (const inputFile of inputFiles) {
+  if (mtime(inputFile) > outputMtime) {
+    console.log(`File '${inputFile}' has changed. Re-run 'script/build-wasm'.`);
+    process.exit(1);
+  }
+}
+
+function list(dir) {
+  return fs.readdirSync(path.join(__dirname, dir), 'utf8')
+    .filter(p => !p.startsWith('.'))
+    .map(p => path.join(dir, p));
+}
+
+function mtime(p) {
+  return fs.statSync(path.join(__dirname, p)).mtime;
+}

lib/binding_web/package.json

@@ -1,13 +1,14 @@
 {
-  "name": "tree-sitter.wasm",
-  "version": "0.0.1",
+  "name": "web-tree-sitter",
+  "version": "0.15.1",
   "description": "Tree-sitter bindings for the web",
-  "main": "index.js",
+  "main": "tree-sitter.js",
   "directories": {
     "test": "test"
   },
   "scripts": {
-    "test": "mocha"
+    "test": "mocha",
+    "prepublish": "node check-artifacts-fresh.js"
   },
   "repository": {
     "type": "git",
@@ -22,7 +23,7 @@
   "bugs": {
     "url": "https://github.com/tree-sitter/tree-sitter/issues"
   },
-  "homepage": "https://github.com/tree-sitter/tree-sitter#readme",
+  "homepage": "https://github.com/tree-sitter/tree-sitter/tree/master/lib/binding_web",
   "devDependencies": {
     "chai": "^4.2.0",
     "mocha": "^6.1.4",

lib/binding_web/test/helper.js

@@ -1,6 +1,8 @@
-const release = '../../../target/release'
-const Parser = require(`${release}/tree-sitter.js`);
-const languageURL = name => require.resolve(`${release}/tree-sitter-${name}.wasm`);
+const Parser = require(`..`);
+
+function languageURL(name) {
+  return require.resolve(`../../../target/release/tree-sitter-${name}.wasm`);
+}
 
 module.exports = Parser.init().then(async () => ({
   Parser,