Working browser + node build with tests and everything

Webpack + Karma has been a massive pain, but I think this setup is
enough to get it all happy!

Author: pimterry

build.js

@@ -9,13 +9,9 @@ shell.rm('-rf', 'pkg');
 shell.rm('-rf', 'dist');
 shell.mkdir('dist');
 
-// Copy the core web files into dist
+// Create the bundler output
 shell.exec('wasm-pack build --target bundler');
-shell.cp('pkg/brotli_wasm*', 'dist');
-shell.rm('-rf', 'pkg');
-shell.mv('dist/brotli_wasm.js', 'dist/browser-bundle.js');
+shell.mv('pkg', 'pkg.bundler');
 
-// Copy the node wrapper into dist too
 shell.exec('wasm-pack build --target nodejs');
-shell.cp('pkg/brotli_wasm.js', 'dist/node.js');
-shell.rm('-rf', 'pkg');
+shell.mv('pkg', 'pkg.node');

karma.conf.js

@@ -0,0 +1,72 @@
+const tmp = require('tmp');
+tmp.setGracefulCleanup();
+
+const webpack = require('webpack');
+
+const outputDir = tmp.dirSync({ unsafeCleanup: true }).name;
+
+module.exports = function(config) {
+    config.set({
+        frameworks: ['mocha', 'chai', 'webpack'],
+        files: [
+            'test/**/*.spec.ts',
+            // Required due to https://github.com/ryanclark/karma-webpack/issues/498. Results in an
+            // annoying warning before the webpack build, but then it works fine.
+            { pattern: `${outputDir}/*.wasm`, included: false, served: true }
+        ],
+        mime: {
+            'text/x-typescript': ['ts']
+        },
+        webpack: {
+            mode: 'development',
+            devtool: 'source-map',
+            module: {
+                rules: [
+                    {
+                        test: /\.ts$/,
+                        loader: 'ts-loader',
+                        options: {
+                            configFile: 'test/tsconfig.json',
+                            compilerOptions: {
+                                outDir: tmp.dirSync({ unsafeCleanup: true }).name
+                            }
+                        },
+                        exclude: /node_modules/
+                    }
+                ]
+            },
+            resolve: {
+                extensions: ['.ts', '.js'],
+                fallback: {
+                    buffer: require.resolve('buffer/')
+                }
+            },
+            experiments: {
+                asyncWebAssembly: true
+            },
+            plugins: [
+                new webpack.ProvidePlugin({
+                    Buffer: ['buffer', 'Buffer'],
+                })
+            ],
+            output: {
+                path: outputDir
+            }
+        },
+        webpackMiddleware: {
+            stats: 'error-only'
+        },
+        preprocessors: {
+            'test/**/*.ts': ['webpack', 'sourcemap']
+        },
+        reporters: ['spec'],
+        port: 9876,
+        logLevel: config.LOG_INFO,
+
+        browsers: ['ChromeHeadless'],
+
+        autoWatch: false,
+        singleRun: true,
+        concurrency: Infinity
+    });
+};

package.json

@@ -2,11 +2,17 @@
   "name": "brotli-wasm",
   "version": "1.0.0",
   "description": "A compressor and decompressor for Brotli that actually works, for node & browsers",
-  "main": "dist/node.js",
-  "browser": "dist/browser.js",
+  "main": "./pkg.node/brotli_wasm.js",
+  "types": "./pkg.node/brotli_wasm.d.ts",
+  "browser": "./pkg.bundler/brotli_wasm.js",
+  "sideEffects": false,
   "scripts": {
     "build": "node ./build.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "pretest": "npm run build",
+    "test": "npm run test:node && npm run test:browser",
+    "test:node": "TS_NODE_FILES=true mocha -r ts-node/register 'test/**/*.spec.ts'",
+    "test:browser": "karma start",
+    "test:browser:debug": "npm run test:browser -- --single-run=false --browsers Chrome"
   },
   "repository": {
     "type": "git",
@@ -25,7 +31,25 @@
   },
   "homepage": "https://github.com/httptoolkit/brotli-wasm#readme",
   "devDependencies": {
+    "@types/chai": "^4.2.18",
+    "@types/mocha": "^8.2.2",
+    "@types/node": "^15.6.0",
+    "buffer": "^6.0.3",
+    "chai": "^4.3.4",
+    "karma": "^6.3.2",
+    "karma-chai": "^0.1.0",
+    "karma-chrome-launcher": "^3.1.0",
+    "karma-mocha": "^2.0.1",
+    "karma-sourcemap-loader": "^0.3.8",
+    "karma-spec-reporter": "0.0.32",
+    "karma-typescript": "^5.5.1",
+    "karma-webpack": "^5.0.0",
+    "mocha": "^8.4.0",
     "shelljs": "^0.8.4",
-    "wasm-pack": "^0.9.1"
+    "ts-loader": "^9.2.1",
+    "ts-node": "^9.1.1",
+    "typescript": "^4.2.4",
+    "wasm-pack": "^0.9.1",
+    "webpack": "^5.37.1"
   }
 }

test/brotli.spec.ts

@@ -0,0 +1,38 @@
+import { expect } from 'chai';
+import * as brotliPromise from '..';
+
+describe("Brotli-wasm", () => {
+
+    let brotli: typeof import('..');
+    beforeEach(async () => {
+        brotli = await brotliPromise;
+    });
+
+    it("can compress data", () => {
+        const input = Buffer.from("Test input data");
+        const result = brotli.compress(input);
+        expect(Buffer.from(result).toString('base64')).to.equal('Gw4A+KWpyubolCCjVAjmxJ4D');
+    });
+
+    it("can decompress data", () => {
+        // Generated with: echo -n '$CONTENT' | brotli --stdout - | base64
+        const input = Buffer.from('GxoAABypU587dC0k9ianQOgqjS32iUTcCA==', 'base64');
+        const result = brotli.decompress(input);
+        expect(Buffer.from(result).toString('utf8')).to.equal('Brotli brotli brotli brotli');
+    });
+
+    it("cleanly fails when decompressing garbage", () => {
+        const input = Buffer.from("This is not brotli data, it's just a string");
+        expect(() =>
+            brotli.decompress(input)
+        ).to.throw('Brotli decompress failed');
+    });
+
+    it("can compress & decompress back to the original result", () => {
+        const input = "Some thrilling text I urgently need to compress";
+        const result = Buffer.from(
+            brotli.decompress(brotli.compress(Buffer.from(input)))
+        ).toString('utf8');
+        expect(result).to.equal(input);
+    });
+});

test/tsconfig.json

@@ -0,0 +1,12 @@
+{
+    "compilerOptions": {
+        "target": "es6",
+        "module": "commonjs",
+        "declaration": true,
+        "sourceMap": true,
+        "strict": true
+    },
+    "include": [
+        "**/*.ts"
+    ]
+}