Implement pure annotation for createPlugin (fusionjs#287)

build/babel-plugins/babel-plugin-pure-create-plugin/index.js

@@ -0,0 +1,35 @@
+// @flow
+/* eslint-env node */
+const createNamedModuleVisitor = require('../babel-plugin-utils/visit-named-module');
+
+module.exports = pureCreatePlugin;
+
+function pureCreatePlugin(babel /*: Object */) {
+  const t = babel.types;
+  const visitor = createNamedModuleVisitor(
+    t,
+    'createPlugin',
+    'fusion-core',
+    refsHandler
+  );
+  return {visitor};
+}
+
+function refsHandler(t, context, refs = []) {
+  refs.forEach(refPath => {
+    const parentPath = refPath.parentPath;
+    if (!t.isCallExpression(parentPath)) {
+      return;
+    }
+    parentPath.addComment('leading', '#__PURE__');
+    if (parentPath.parentPath.type === 'ExportDefaultDeclaration') {
+      const id = parentPath.parentPath.scope.generateUidIdentifier('default');
+      parentPath.parentPath.insertBefore(
+        t.variableDeclaration('var', [
+          t.variableDeclarator(id, parentPath.parentPath.node.declaration),
+        ])
+      );
+      parentPath.parentPath.node.declaration = id;
+    }
+  });
+}

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/create-plugin-default-and-named

@@ -0,0 +1,4 @@
+import {createPlugin} from 'fusion-core';
+
+export const p = createPlugin({});
+export default createPlugin({});

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/create-plugin-default-export

@@ -0,0 +1,3 @@
+import {createPlugin} from 'fusion-core';
+
+export default createPlugin({});

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/create-plugin-default-multiline

@@ -0,0 +1,9 @@
+import {createPlugin} from 'fusion-core';
+
+export default createPlugin({
+  deps: {
+    a: 'b',
+  },
+  provides: () => {
+  }
+});

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/expected-default-and-named

@@ -0,0 +1,10 @@
+import { createPlugin } from 'fusion-core';
+export const p =
+/*#__PURE__*/
+createPlugin({});
+
+var _default =
+/*#__PURE__*/
+createPlugin({});
+
+export default _default;

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/expected-default-export

@@ -0,0 +1,7 @@
+import { createPlugin } from 'fusion-core';
+
+var _default =
+/*#__PURE__*/
+createPlugin({});
+
+export default _default;

build/babel-plugins/babel-plugin-pure-create-plugin/test/fixtures/expected-default-multiline

@@ -0,0 +1,12 @@
+import { createPlugin } from 'fusion-core';
+
+var _default =
+/*#__PURE__*/
+createPlugin({
+  deps: {
+    a: 'b'
+  },
+  provides: () => {}
+});
+
+export default _default;

build/babel-plugins/babel-plugin-pure-create-plugin/test/index.js

@@ -0,0 +1,37 @@
+// @flow
+/* eslint-env node */
+const fs = require('fs');
+const test = require('tape');
+const {transformFileSync} = require('babel-core');
+const plugin = require('../');
+
+function getOutput(file) {
+  return transformFileSync(__dirname + file, {
+    plugins: [plugin],
+  }).code;
+}
+
+function readExpected(file) {
+  return fs.readFileSync(__dirname + file).toString();
+}
+
+test('createPlugin default export', t => {
+  const output = getOutput('/fixtures/create-plugin-default-export');
+  const expected = readExpected('/fixtures/expected-default-export');
+  t.equal(output, expected);
+  t.end();
+});
+
+test('createPlugin default and named export', t => {
+  const output = getOutput('/fixtures/create-plugin-default-and-named');
+  const expected = readExpected('/fixtures/expected-default-and-named');
+  t.equal(output, expected);
+  t.end();
+});
+
+test('createPlugin default export multiline', t => {
+  const output = getOutput('/fixtures/create-plugin-default-multiline');
+  const expected = readExpected('/fixtures/expected-default-multiline');
+  t.equal(output, expected);
+  t.end();
+});

build/compiler.js

@@ -228,6 +228,9 @@ function getConfig({target, env, dir, watch, cover}) {
                   //cup-globals works with webpack.EnvironmentPlugin(['NODE_ENV']) to implement static conditionals
                   require.resolve('@babel/plugin-syntax-dynamic-import'),
                   require.resolve('./babel-plugins/babel-plugin-asseturl'),
+                  require.resolve(
+                    './babel-plugins/babel-plugin-pure-create-plugin'
+                  ),
                   require.resolve(
                     './babel-plugins/babel-plugin-sync-chunk-ids'
                   ),
@@ -452,6 +455,7 @@ function getConfig({target, env, dir, watch, cover}) {
         }),
     ].filter(Boolean),
     optimization: {
+      sideEffects: true,
       splitChunks: target === 'web' && {
         // See https://webpack.js.org/guides/code-splitting/
         // See https://gist.github.com/sokra/1522d586b8e5c0f5072d7565c2bee693

test/cli/build.js

@@ -267,3 +267,69 @@ test('`fusion build` with dynamic imports', async t => {
   );
   t.end();
 });
+
+test('`fusion build` tree shaking', async t => {
+  const dir = path.resolve(__dirname, '../fixtures/tree-shaking');
+  await cmd(`build --dir=${dir} --production=true`);
+
+  const serverMain = path.resolve(
+    dir,
+    `.fusion/dist/production/server/server-main.js`
+  );
+  const clientFiles = await readdir(
+    path.resolve(dir, '.fusion/dist/production/client')
+  );
+  const clientMainFile = clientFiles.filter(f =>
+    /client-main-(.*?).js$/.test(f)
+  )[0];
+  const clientMain = path.resolve(
+    dir,
+    '.fusion/dist/production/client',
+    clientMainFile
+  );
+
+  // Manually instrumented
+  t.ok(
+    !fs
+      .readFileSync(serverMain, 'utf-8')
+      .includes('instrumented-as-pure-browser-plugin'),
+    'should not include browserPlugin in node'
+  );
+
+  t.ok(
+    !fs
+      .readFileSync(clientMain, 'utf-8')
+      .includes('instrumented-as-pure-node-plugin'),
+    'should not include nodePlugin in browser'
+  );
+
+  // Default export
+  t.ok(
+    !fs
+      .readFileSync(serverMain, 'utf-8')
+      .includes('default-export-browser-plugin'),
+    'should not include default browser export in node'
+  );
+
+  t.ok(
+    !fs
+      .readFileSync(clientMain, 'utf-8')
+      .includes('default-export-node-plugin'),
+    'should not include default node export in browser'
+  );
+
+  // Named export
+  t.ok(
+    !fs
+      .readFileSync(serverMain, 'utf-8')
+      .includes('named-export-browser-plugin'),
+    'should not include named browser export in node'
+  );
+
+  t.ok(
+    !fs.readFileSync(clientMain, 'utf-8').includes('named-export-node-plugin'),
+    'should not include named node export in browser'
+  );
+
+  t.end();
+});

test/fixtures/tree-shaking/src/main.js

@@ -10,8 +10,21 @@ import readline from 'readline';
 import repl from 'repl';
 import tls from 'tls';
 
+import defaultExportBrowserPlugin from './plugins/default-export-browser.js';
+import defaultExportNodePlugin from './plugins/default-export-node.js';
+import instrumentedAsPureBrowserPlugin from './plugins/instrumented-as-pure-browser.js';
+import instrumentedAsPureNodePlugin from './plugins/instrumented-as-pure-node.js';
+import {plugin as namedExportBrowserPlugin} from './plugins/named-export-browser.js';
+import {plugin as namedExportNodePlugin} from './plugins/named-export-node.js';
+
 export default async function() {
   const app = new App('element', el => el);
+  __BROWSER__ && app.register(defaultExportBrowserPlugin);
+  __NODE__ && app.register(defaultExportNodePlugin);
+  __BROWSER__ && app.register(instrumentedAsPureBrowserPlugin);
+  __NODE__ && app.register(instrumentedAsPureNodePlugin);
+  __BROWSER__ && app.register(namedExportBrowserPlugin);
+  __NODE__ && app.register(namedExportNodePlugin);
   __NODE__ &&
     app.middleware((ctx, next) => {
       if (ctx.url === '/fs') {

test/fixtures/tree-shaking/src/plugins/default-export-browser.js

@@ -0,0 +1,7 @@
+import {createPlugin} from 'fusion-core';
+
+export default createPlugin({
+  provides() {
+    console.log('default-export-browser-plugin');
+  },
+});

test/fixtures/tree-shaking/src/plugins/default-export-node.js

@@ -0,0 +1,7 @@
+import {createPlugin} from 'fusion-core';
+
+export default createPlugin({
+  provides() {
+    console.log('default-export-node-plugin');
+  },
+});

test/fixtures/tree-shaking/src/plugins/instrumented-as-pure-browser.js

@@ -0,0 +1,8 @@
+import {createPlugin} from 'fusion-core';
+
+const PLUGIN = /*@__PURE__*/ createPlugin({
+  provides() {
+    console.log('instrumented-as-pure-browser-plugin');
+  },
+});
+export default PLUGIN;

test/fixtures/tree-shaking/src/plugins/instrumented-as-pure-node.js

@@ -0,0 +1,8 @@
+import {createPlugin} from 'fusion-core';
+
+const PLUGIN = /*@__PURE__*/ createPlugin({
+  provides() {
+    console.log('instrumented-as-pure-node-plugin');
+  },
+});
+export default PLUGIN;

test/fixtures/tree-shaking/src/plugins/named-export-browser.js

@@ -0,0 +1,9 @@
+import {createPlugin} from 'fusion-core';
+
+const plugin = createPlugin({
+  provides() {
+    console.log('named-export-browser-plugin');
+  },
+});
+
+export {plugin};

test/fixtures/tree-shaking/src/plugins/named-export-node.js

@@ -0,0 +1,9 @@
+import {createPlugin} from 'fusion-core';
+
+const plugin = createPlugin({
+  provides() {
+    console.log('named-export-node-plugin');
+  },
+});
+
+export {plugin};

test/index.js

@@ -10,6 +10,7 @@ require('./route-prefix.js');
 /*
 require('./browser-support');
 */
+require('../build/babel-plugins/babel-plugin-pure-create-plugin/test');
 require('../build/babel-plugins/babel-plugin-asseturl/test');
 require('../build/babel-plugins/babel-plugin-chunkid/test');
 require('../build/babel-plugins/babel-plugin-experimentation/test');