Add useSyntax option and deprecate Uglify target

Author: existentialism

README.md

@@ -120,16 +120,6 @@ A query to select browsers (ex: last 2 versions, > 5%) using [browserslist](http
 
 Note, browsers' results are overridden by explicit items from `targets`.
 
-### `targets.uglify`
-
-`number | true`
-
-UglifyJS does not currently support any ES6 syntax, so if you are using Uglify to minify your code, targeting later browsers may cause Uglify to throw syntax errors.
-
-To prevent these errors - specify the uglify option, which will enable all plugins and, as a result, fully compile your code to ES5. However, the `useBuiltIns` option will still work as before, and only include the polyfills that your target(s) need.
-
-> NOTE: Uglify has a work-in-progress "Harmony" branch to address the lack of ES6 support, but it is not yet stable.  You can follow its progress in [UglifyJS2 issue #448](https://github.com/mishoo/UglifyJS2/issues/448).  If you require an alternative minifier which _does_ support ES6 syntax, we recommend using [Babili](https://github.com/babel/babili).
-
 ### `loose`
 
 `boolean`, defaults to `false`.
@@ -249,6 +239,16 @@ import "babel-polyfill/core-js/modules/es7.string.pad-end";
 
 Don't add polyfills automatically per file, or transform `import "babel-polyfill"` to individual polyfills.
 
+### `useSyntax`
+
+`boolean`, defaults to `true`.
+
+NOTE: `targets.uglify` is deprecated and will be removed in the next major in favor of this.
+
+Runs the transforms needed for the targeted environment(s). Set this to `false` if you want to force running _all_ transforms which is useful if the output will be run through UglifyJS, or an environment that only supports ES5.
+
+> NOTE: Uglify has a work-in-progress "Harmony" branch to address the lack of ES6 support, but it is not yet stable.  You can follow its progress in [UglifyJS2 issue #448](https://github.com/mishoo/UglifyJS2/issues/448).  If you require an alternative minifier which _does_ support ES6 syntax, we recommend using [Babili](https://github.com/babel/babili).
+
 ---
 
 ## Examples

src/index.js

@@ -56,15 +56,12 @@ let hasBeenLogged = false;
 
 const logPlugin = (plugin, targets, list) => {
   const envList = list[plugin] || {};
-  const filteredList = Object.keys(targets).reduce(
-    (a, b) => {
-      if (!envList[b] || semver.lt(targets[b], semverify(envList[b]))) {
-        a[b] = prettifyVersion(targets[b]);
-      }
-      return a;
-    },
-    {},
-  );
+  const filteredList = Object.keys(targets).reduce((a, b) => {
+    if (!envList[b] || semver.lt(targets[b], semverify(envList[b]))) {
+      a[b] = prettifyVersion(targets[b]);
+    }
+    return a;
+  }, {});
   const logStr = `  ${plugin} ${JSON.stringify(filteredList)}`;
   console.log(logStr);
 };
@@ -121,18 +118,41 @@ const filterItems = (list, includes, excludes, targets, defaultItems) => {
 };
 
 export default function buildPreset(context, opts = {}) {
-  const validatedOptions = normalizeOptions(opts);
-  const { debug, loose, moduleType, useBuiltIns } = validatedOptions;
+  const {
+    debug,
+    exclude: optionsExclude,
+    include: optionsInclude,
+    loose,
+    moduleType,
+    targets: optionsTargets,
+    useBuiltIns,
+    useSyntax,
+  } = normalizeOptions(opts);
+
+  // TODO: remove this in next major
+  let hasUglifyTarget = false;
+
+  if (optionsTargets && optionsTargets.uglify) {
+    hasUglifyTarget = true;
+    delete optionsTargets.uglify;
+
+    console.log("");
+    console.log("The uglify target has been deprecated. Set the top level");
+    console.log("option `useSyntax: false` instead.");
+    console.log("");
+  }
+
+  const targets = getTargets(optionsTargets);
+  const include = transformIncludesAndExcludes(optionsInclude);
+  const exclude = transformIncludesAndExcludes(optionsExclude);
 
-  const targets = getTargets(validatedOptions.targets);
-  const include = transformIncludesAndExcludes(validatedOptions.include);
-  const exclude = transformIncludesAndExcludes(validatedOptions.exclude);
+  const transformTargets = !useSyntax || hasUglifyTarget ? {} : targets;
 
   const transformations = filterItems(
     pluginList,
     include.plugins,
     exclude.plugins,
-    targets,
+    transformTargets,
   );
 
   let polyfills;
@@ -156,10 +176,26 @@ export default function buildPreset(context, opts = {}) {
     console.log("\nUsing targets:");
     console.log(JSON.stringify(prettifyTargets(targets), null, 2));
     console.log(`\nModules transform: ${moduleType}`);
-    console.log("\nUsing plugins:");
-    transformations.forEach(transform => {
-      logPlugin(transform, targets, pluginList);
-    });
+    console.log("");
+    console.log("Plugins");
+    console.log("=========");
+    console.log("");
+
+    if (!transformations.size) {
+      console.log("Based on your targets none were added.");
+    } else {
+      if (!useSyntax) {
+        console.log("Added all plugins (useSyntax: false):");
+      } else if (hasUglifyTarget) {
+        console.log("Added all plugins (target: uglify):");
+      } else {
+        console.log("Added the following plugins based on your targets:");
+      }
+
+      transformations.forEach(transform => {
+        logPlugin(transform, transformTargets, pluginList);
+      });
+    }
   }
 
   const plugins = [];
@@ -172,7 +208,8 @@ export default function buildPreset(context, opts = {}) {
   }
 
   transformations.forEach(pluginName =>
-    plugins.push([require(`babel-plugin-${pluginName}`), { loose }]));
+    plugins.push([require(`babel-plugin-${pluginName}`), { loose }]),
+  );
 
   const regenerator = transformations.has("transform-regenerator");
 

src/normalize-options.js

@@ -43,18 +43,24 @@ export const checkDuplicateIncludeExcludes = (include = [], exclude = []) => {
   );
 };
 
-// TODO: Allow specifying plugins as either shortened or full name
-// babel-plugin-transform-es2015-classes
-// transform-es2015-classes
-export const validateLooseOption = (looseOpt = false) => {
-  invariant(
-    typeof looseOpt === "boolean",
-    "Invalid Option: The 'loose' option must be a boolean.",
-  );
+export const validateBoolOption = (name, value, defaultValue) => {
+  if (typeof value === "undefined") {
+    value = defaultValue;
+  }
 
-  return looseOpt;
+  if (typeof value !== "boolean") {
+    throw new Error(`Preset env: '${name}' option must be a boolean.`);
+  }
+
+  return value;
 };
 
+export const validateLooseOption = looseOpt =>
+  validateBoolOption("loose", looseOpt, false);
+
+export const validateUseSyntaxOption = useSyntax =>
+  validateBoolOption("useSyntax", useSyntax, true);
+
 export const validateModulesOption = (modulesOpt = "commonjs") => {
   invariant(
     modulesOpt === false ||
@@ -97,5 +103,6 @@ export default function normalizeOptions(opts) {
     moduleType: validateModulesOption(opts.modules),
     targets: opts.targets,
     useBuiltIns: validateUseBuiltInsOption(opts.useBuiltIns),
+    useSyntax: validateUseSyntaxOption(opts.useSyntax),
   };
 }

src/targets-parser.js

@@ -25,30 +25,27 @@ const semverMin = (first: ?string, second: string): string => {
 };
 
 const getLowestVersions = browsers => {
-  return browsers.reduce(
-    (all, browser) => {
-      const [browserName, browserVersion] = browser.split(" ");
-      const normalizedBrowserName = browserNameMap[browserName];
+  return browsers.reduce((all, browser) => {
+    const [browserName, browserVersion] = browser.split(" ");
+    const normalizedBrowserName = browserNameMap[browserName];
 
-      if (!normalizedBrowserName) {
-        return all;
-      }
+    if (!normalizedBrowserName) {
+      return all;
+    }
 
-      try {
-        // Browser version can return as "10.0-10.2"
-        const splitVersion = browserVersion.split("-")[0];
-        const parsedBrowserVersion = semverify(splitVersion);
+    try {
+      // Browser version can return as "10.0-10.2"
+      const splitVersion = browserVersion.split("-")[0];
+      const parsedBrowserVersion = semverify(splitVersion);
 
-        all[normalizedBrowserName] = semverMin(
-          all[normalizedBrowserName],
-          parsedBrowserVersion,
-        );
-      } catch (e) {}
+      all[normalizedBrowserName] = semverMin(
+        all[normalizedBrowserName],
+        parsedBrowserVersion,
+      );
+    } catch (e) {}
 
-      return all;
-    },
-    {},
-  );
+    return all;
+  }, {});
 };
 
 const outputDecimalWarning = (decimalTargets: Array<Object>): void => {
@@ -59,7 +56,8 @@ const outputDecimalWarning = (decimalTargets: Array<Object>): void => {
   console.log("Warning, the following targets are using a decimal version:");
   console.log("");
   decimalTargets.forEach(({ target, value }) =>
-    console.log(`  ${target}: ${value}`));
+    console.log(`  ${target}: ${value}`),
+  );
   console.log("");
   console.log(
     "We recommend using a string for minor/patch versions to avoid numbers like 6.10",
@@ -80,6 +78,7 @@ const targetParserMap = {
     return [target, parsed];
   },
 
+  // TODO: Remove in next version.
   // Only valid value for Uglify is `true`
   uglify: (target, value) => [target, value === true],
 };

test/debug-fixtures/builtins-uglify/stdout.txt

@@ -1,37 +1,42 @@
+The uglify target has been deprecated. Set the top level
+option `useSyntax: false` instead.
+
 babel-preset-env: `DEBUG` option
 
 Using targets:
 {
-  "chrome": "55",
-  "uglify": true
+  "chrome": "55"
 }
 
 Modules transform: false
 
-Using plugins:
-  check-es2015-constants {"uglify":true}
-  transform-es2015-arrow-functions {"uglify":true}
-  transform-es2015-block-scoped-functions {"uglify":true}
-  transform-es2015-block-scoping {"uglify":true}
-  transform-es2015-classes {"uglify":true}
-  transform-es2015-computed-properties {"uglify":true}
-  transform-es2015-destructuring {"uglify":true}
-  transform-es2015-duplicate-keys {"uglify":true}
-  transform-es2015-for-of {"uglify":true}
-  transform-es2015-function-name {"uglify":true}
-  transform-es2015-literals {"uglify":true}
-  transform-es2015-object-super {"uglify":true}
-  transform-es2015-parameters {"uglify":true}
-  transform-es2015-shorthand-properties {"uglify":true}
-  transform-es2015-spread {"uglify":true}
-  transform-es2015-sticky-regex {"uglify":true}
-  transform-es2015-template-literals {"uglify":true}
-  transform-es2015-typeof-symbol {"uglify":true}
-  transform-es2015-unicode-regex {"uglify":true}
-  transform-regenerator {"uglify":true}
-  transform-exponentiation-operator {"uglify":true}
-  transform-async-to-generator {"uglify":true}
-  syntax-trailing-function-commas {"chrome":"55","uglify":true}
+Plugins
+=========
+
+Added all plugins (target: uglify):
+  check-es2015-constants {}
+  transform-es2015-arrow-functions {}
+  transform-es2015-block-scoped-functions {}
+  transform-es2015-block-scoping {}
+  transform-es2015-classes {}
+  transform-es2015-computed-properties {}
+  transform-es2015-destructuring {}
+  transform-es2015-duplicate-keys {}
+  transform-es2015-for-of {}
+  transform-es2015-function-name {}
+  transform-es2015-literals {}
+  transform-es2015-object-super {}
+  transform-es2015-parameters {}
+  transform-es2015-shorthand-properties {}
+  transform-es2015-spread {}
+  transform-es2015-sticky-regex {}
+  transform-es2015-template-literals {}
+  transform-es2015-typeof-symbol {}
+  transform-es2015-unicode-regex {}
+  transform-regenerator {}
+  transform-exponentiation-operator {}
+  transform-async-to-generator {}
+  syntax-trailing-function-commas {}
 
 Polyfills
 =========

test/debug-fixtures/builtins/stdout.txt

@@ -9,7 +9,10 @@ Using targets:
 
 Modules transform: commonjs
 
-Using plugins:
+Plugins
+=========
+
+Added the following plugins based on your targets:
   check-es2015-constants {"ie":"10"}
   transform-es2015-arrow-functions {"ie":"10"}
   transform-es2015-block-scoped-functions {"ie":"10"}

test/debug-fixtures/electron/stdout.txt

@@ -14,7 +14,10 @@ Using targets:
 
 Modules transform: commonjs
 
-Using plugins:
+Plugins
+=========
+
+Added the following plugins based on your targets:
   check-es2015-constants {"electron":"0.36"}
   transform-es2015-block-scoping {"electron":"0.36"}
   transform-es2015-destructuring {"electron":"0.36"}

test/debug-fixtures/plugins-only/stdout.txt

@@ -15,7 +15,10 @@ Using targets:
 
 Modules transform: commonjs
 
-Using plugins:
+Plugins
+=========
+
+Added the following plugins based on your targets:
   transform-es2015-destructuring {"firefox":"52"}
   transform-es2015-for-of {"firefox":"52"}
   transform-es2015-function-name {"firefox":"52"}

test/debug-fixtures/specific-targets/stdout.txt

@@ -12,7 +12,10 @@ Using targets:
 
 Modules transform: commonjs
 
-Using plugins:
+Plugins
+=========
+
+Added the following plugins based on your targets:
   check-es2015-constants {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
   transform-es2015-arrow-functions {"ie":"10","ios":"9","safari":"7"}
   transform-es2015-block-scoped-functions {"ie":"10","ios":"9","safari":"7"}

test/debug-fixtures/use-syntax-false/options.json

@@ -0,0 +1,13 @@
+{
+  "presets": [
+    ["../../lib", {
+      "debug": true,
+      "modules": false,
+      "targets": {
+        "chrome": 55
+      },
+      "useBuiltIns": "entry",
+      "useSyntax": false
+    }]
+  ]
+}