Move uglify into own worker for every chunk

Moved uglify call into worker which may significantly reduce build
time in projects with code splitting.

This required to remove `minifier` option. Prefer using `terser` plugin
instead.

index.js

@@ -1,22 +1,29 @@
 const { codeFrameColumns } = require("@babel/code-frame");
-const { minify } = require("uglify-js");
+const Worker = require("jest-worker").default;
 
-function uglify(userOptions, minifier = minify) {
+function uglify(userOptions) {
   const options = Object.assign({ sourceMap: true }, userOptions);
 
   return {
     name: "uglify",
 
     transformBundle(code) {
-      const result = minifier(code, options);
-      if (result.error) {
-        const { message, line, col: column } = result.error;
-        console.error(
-          codeFrameColumns(code, { start: { line, column } }, { message })
-        );
-        throw result.error;
-      }
-      return result;
+      const worker = new Worker(require.resolve("./transform.js"));
+
+      return worker
+        .transform(code, options)
+        .then(result => {
+          worker.end();
+          return result;
+        })
+        .catch(error => {
+          worker.end();
+          const { message, line, col: column } = error;
+          console.error(
+            codeFrameColumns(code, { start: { line, column } }, { message })
+          );
+          throw error;
+        });
     }
   };
 }

package.json

@@ -33,6 +33,6 @@
     "babel-jest": "^22.4.4",
     "jest": "^22.4.4",
     "prettier": "^1.12.1",
-    "rollup": "^0.59.1"
+    "rollup": "^0.65.0"
   }
 }

test/__snapshots__/test.js.snap

@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`works with code splitting 1`] = `
+Object {
+  "chunk-1.js": Object {
+    "code": "var chunk1=\\"chunk-1\\";console.log(chunk1);
+",
+    "exports": Array [],
+    "fileName": "chunk-1.js",
+    "imports": Array [],
+    "isEntry": true,
+    "map": null,
+    "modules": Object {
+      "/Users/trysound/host/rollup-plugin-uglify/test/fixtures/chunk-1.js": Object {
+        "originalLength": 44,
+        "removedExports": Array [],
+        "renderedExports": Array [],
+        "renderedLength": 44,
+      },
+    },
+  },
+  "chunk-2.js": Object {
+    "code": "var chunk2=\\"chunk-2\\";console.log(chunk2);
+",
+    "exports": Array [],
+    "fileName": "chunk-2.js",
+    "imports": Array [],
+    "isEntry": true,
+    "map": null,
+    "modules": Object {
+      "/Users/trysound/host/rollup-plugin-uglify/test/fixtures/chunk-2.js": Object {
+        "originalLength": 44,
+        "removedExports": Array [],
+        "renderedExports": Array [],
+        "renderedLength": 44,
+      },
+    },
+  },
+}
+`;

test/fixtures/chunk-1.js

@@ -0,0 +1,2 @@
+var chunk1 = 'chunk-1';
+console.log(chunk1)

test/fixtures/chunk-2.js

@@ -0,0 +1,2 @@
+var chunk2 = 'chunk-2';
+console.log(chunk2)

test/test.js

@@ -9,7 +9,9 @@ test("minify", async () => {
     plugins: [uglify()]
   });
   const result = await bundle.generate({ format: "cjs" });
-  expect(result.code).toEqual('"use strict";window.a=5,window.a<3&&console.log(4);\n');
+  expect(result.code).toEqual(
+    '"use strict";window.a=5,window.a<3&&console.log(4);\n'
+  );
   expect(result.map).toBeFalsy();
 });
 
@@ -35,29 +37,6 @@ test("minify with sourcemaps", async () => {
   expect(result.map).toBeTruthy();
 });
 
-test("allow passing minifier", async () => {
-  const expectedCode = readFile("test/fixtures/plain-file.js", "utf-8");
-  const testOptions = {
-    foo: "bar"
-  };
-
-  const bundle = await rollup({
-    input: "test/fixtures/plain-file.js",
-    plugins: [
-      uglify(testOptions, (code, options) => {
-        expect(code.trim()).toEqual(expectedCode.trim());
-        expect(options).toEqual({
-          foo: "bar",
-          sourceMap: true
-        });
-        return { code };
-      })
-    ]
-  });
-  const result = await bundle.generate({ format: "es" });
-  expect(result.code.trim()).toEqual(expectedCode.trim());
-});
-
 test("throw error on uglify fail", async () => {
   try {
     const bundle = await rollup({
@@ -69,9 +48,19 @@ test("throw error on uglify fail", async () => {
         uglify()
       ]
     });
-    await bundle.generate({ format: "es" });
+    await bundle.generate({ format: "esm" });
     expect(true).toBeFalsy();
   } catch (error) {
     expect(error.toString()).toMatch(/Name expected/);
   }
 });
+
+test("works with code splitting", async () => {
+  const bundle = await rollup({
+    input: ["test/fixtures/chunk-1.js", "test/fixtures/chunk-2.js"],
+    experimentalCodeSplitting: true,
+    plugins: [uglify()]
+  });
+  const { output } = await bundle.generate({ format: "esm" });
+  expect(output).toMatchSnapshot();
+});

transform.js

@@ -0,0 +1,12 @@
+const { minify } = require("uglify-js");
+
+const transform = (code, options) => {
+  const result = minify(code, options);
+  if (result.error) {
+    throw result.error;
+  } else {
+    return result;
+  }
+};
+
+exports.transform = transform;

yarn.lock

@@ -2857,9 +2857,9 @@ rimraf@^2.6.1:
   dependencies:
     glob "^7.0.5"
 
-rollup@^0.59.1:
-  version "0.59.1"
-  resolved "https://registry.yarnpkg.com/rollup/-/rollup-0.59.1.tgz#86cbceaecd861df1317a0aa29207173de23e6a5d"
+rollup@^0.65.0:
+  version "0.65.0"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-0.65.0.tgz#280db1252169b68fc3043028346b337dde453fba"
   dependencies:
     "@types/estree" "0.0.39"
     "@types/node" "*"