### Added

- Modern and lite builds generated from the same source.
- support ESM.
- Set up GitHub release action / provenance

### Fixed
- Fix uploading coverage to coveralls
- fix recognize environment is node when use browserfs

rollup.config.mjs

@@ -0,0 +1,106 @@
+import commonjs from '@rollup/plugin-commonjs';
+import terser from '@rollup/plugin-terser';
+
+const featureNames = {
+  legacy: 'FEATURE_LEGACY',
+  hmac: 'FEATURE_HMAC',
+  base64: 'FEATURE_BASE64',
+  buffer: 'FEATURE_BUFFER'
+};
+
+const variants = [
+  {
+    name: 'md5',
+    features: {legacy: true, hmac: true, base64: true, buffer: true}
+  },
+  {
+    name: 'md5.modern',
+    features: {legacy: false, hmac: true, base64: true, buffer: true}
+  },
+  {
+    name: 'md5-lite',
+    features: {legacy: false, hmac: false, base64: false, buffer: false}
+  }
+];
+
+const disableNodeJs = {
+  name: 'disable-node-js',
+  transform(code, id) {
+    if (id.endsWith('/src/md5.js')) {
+      const nodeJsDeclaration = /^\s*var NODE_JS = .*;$/m;
+      if (!nodeJsDeclaration.test(code)) {
+        this.error('Could not find the NODE_JS declaration');
+      }
+      return code.replace(nodeJsDeclaration, '  var NODE_JS = false;');
+    }
+  }
+};
+
+const setFeatures = (features) => {
+  return {
+    name: 'set-features',
+    transform(code, id) {
+      if (id.endsWith('/src/md5.js')) {
+        Object.entries(featureNames).forEach(([feature, name]) => {
+          const declaration = `var ${name} = true;`;
+          if (!code.includes(declaration)) {
+            throw new Error(`Could not find declaration for ${name}`);
+          }
+          code = code.replace(declaration, `var ${name} = ${features[feature]};`);
+        });
+        return code;
+      }
+    }
+  }
+};
+
+function build(variant) {
+  return [
+    {
+      input: 'src/md5.js',
+      output: {
+        file: `build/${variant.name}.js`
+      },
+      plugins: [setFeatures(variant.features)]
+    },
+    {
+      input: 'src/md5.mjs',
+      external: ['crypto', 'buffer'],
+      output: {
+        file: `build/${variant.name}.node.mjs`,
+        format: 'es'
+      },
+      plugins: [setFeatures(variant.features), commonjs({
+        strictRequires: false
+      })]
+    },
+    {
+      input: 'src/md5.mjs',
+      output: {
+        file: `build/${variant.name}.mjs`,
+        format: 'es'
+      },
+      plugins: [setFeatures(variant.features), disableNodeJs, commonjs({
+        strictRequires: false,
+        ignore: ['crypto', 'buffer']
+      })]
+    },
+    {
+      input: `build/${variant.name}.js`,
+      output: {
+        file: `build/${variant.name}.min.js`
+      },
+      plugins: [terser()]
+    },
+    {
+      input: `build/${variant.name}.mjs`,
+      output: {
+        file: `build/${variant.name}.min.mjs`,
+        format: 'es'
+      },
+      plugins: [terser()]
+    }
+  ]
+}
+
+export default [...variants.map((variant) => build(variant))].flat();