Add safari technology preview for babel-preset-env. (#6791)

experimental/babel-preset-env/README.md

@@ -181,7 +181,7 @@ For more information on setting options for a preset, refer to the [plugin/prese
 
 Takes an object of environment versions to support.
 
-Each target environment takes a number or a string (we recommend using a string when specifying minor versions like `node: "6.10"`).
+Each target environment takes a number or a string (we recommend using a string when specifying minor versions like `node: "6.10"`). You can also specify `tp` (technology preview) version for Safari.
 
 Example environments: `chrome`, `opera`, `edge`, `firefox`, `safari`, `ie`, `ios`, `android`, `node`, `electron`.
 
@@ -197,7 +197,7 @@ If you want to compile against the current node version, you can specify `"node"
 
 `Array<string> | string`
 
-A query to select browsers (ex: last 2 versions, > 5%) using [browserslist](https://github.com/ai/browserslist).
+A query to select browsers (ex: last 2 versions, > 5%, safari tp) using [browserslist](https://github.com/ai/browserslist).
 
 Note, browsers' results are overridden by explicit items from `targets`.
 

experimental/babel-preset-env/data/built-ins.json

@@ -948,6 +948,7 @@
   },
   "es7.promise.finally": {
     "chrome": "63",
+    "safari": "tp",
     "opera": "50"
   }
 }

experimental/babel-preset-env/data/plugins.json

@@ -231,14 +231,18 @@
   "proposal-async-generator-functions": {
     "chrome": "63",
     "firefox": "57",
+    "safari": "tp",
     "opera": "50"
   },
   "proposal-object-rest-spread": {
     "chrome": "60",
     "firefox": "55",
+    "safari": "tp",
     "node": "8.3",
     "opera": "47"
   },
-  "proposal-optional-catch-binding": {},
+  "proposal-optional-catch-binding": {
+    "safari": "tp"
+  },
   "proposal-unicode-property-regex": {}
 }

experimental/babel-preset-env/data/unreleased-labels.js

@@ -0,0 +1,3 @@
+module.exports = {
+  safari: "tp",
+};

experimental/babel-preset-env/scripts/build-data.js

@@ -7,6 +7,7 @@ const flattenDeep = require("lodash/flattenDeep");
 const isEqual = require("lodash/isEqual");
 const mapValues = require("lodash/mapValues");
 const pickBy = require("lodash/pickBy");
+const unreleasedLabels = require("../data/unreleased-labels");
 const electronToChromiumVersions = require("electron-to-chromium").versions;
 
 const electronToChromiumKeys = Object.keys(
@@ -185,6 +186,7 @@ const getLowestImplementedVersion = ({ features }, env) => {
       return result;
     }, []);
 
+  const unreleasedLabelForEnv = unreleasedLabels[env];
   const envTests = tests.map(({ res: test, isBuiltIn }, i) => {
     // Babel itself doesn't implement the feature correctly,
     // don't count against it
@@ -200,9 +202,15 @@ const getLowestImplementedVersion = ({ features }, env) => {
         .filter(
           test => tests[i].res[test] === true || tests[i].res[test] === "strict"
         )
-        // normalize some keys
-        .map(test => test.replace("_", "."))
-        .filter(test => !isNaN(parseFloat(test.replace(env, ""))))
+        // normalize some keys and get version from full string.
+        .map(test => {
+          return test.replace("_", ".").replace(env, "");
+        })
+        // version must be label from the unreleasedLabels (like tp) or number.
+        .filter(
+          version =>
+            unreleasedLabelForEnv === version || !isNaN(parseFloat(version))
+        )
         .shift()
     );
   });
@@ -220,9 +228,14 @@ const getLowestImplementedVersion = ({ features }, env) => {
     return null;
   }
 
-  return envTests.map(str => Number(str.replace(env, ""))).reduce((a, b) => {
-    return a < b ? b : a;
-  });
+  return envTests
+    .map(str => {
+      const version = str.replace(env, "");
+      return version === unreleasedLabelForEnv ? version : parseFloat(version);
+    })
+    .reduce((a, b) => {
+      return b === unreleasedLabelForEnv || a < b ? b : a;
+    });
 };
 
 const generateData = (environments, features) => {

experimental/babel-preset-env/src/index.js

@@ -16,7 +16,12 @@ import useBuiltInsEntryPlugin from "./use-built-ins-entry-plugin";
 import addUsedBuiltInsPlugin from "./use-built-ins-plugin";
 import getTargets from "./targets-parser";
 import availablePlugins from "./available-plugins";
-import { filterStageFromList, prettifyTargets, semverify } from "./utils";
+import {
+  filterStageFromList,
+  prettifyTargets,
+  semverify,
+  isUnreleasedVersion,
+} from "./utils";
 import type { Plugin, Targets } from "./types";
 
 const getPlugin = (pluginName: string) => {
@@ -61,6 +66,13 @@ export const isPluginRequired = (
 
     const lowestImplementedVersion: string = plugin[environment];
     const lowestTargetedVersion: string = supportedEnvironments[environment];
+    // If targets has unreleased value as a lowest version, then don't require a plugin.
+    if (isUnreleasedVersion(lowestTargetedVersion, environment)) {
+      return false;
+      // Include plugin if it is supported in the unreleased environment, which wasn't specified in targets
+    } else if (isUnreleasedVersion(lowestImplementedVersion, environment)) {
+      return true;
+    }
 
     if (!semver.valid(lowestTargetedVersion)) {
       throw new Error(

experimental/babel-preset-env/src/targets-parser.js

@@ -2,7 +2,7 @@
 
 import browserslist from "browserslist";
 import semver from "semver";
-import { semverify } from "./utils";
+import { semverify, isUnreleasedVersion, getLowestUnreleased } from "./utils";
 import { objectToBrowserslist } from "./normalize-options";
 import type { Targets } from "./types";
 
@@ -20,7 +20,7 @@ const browserNameMap = {
 const isBrowsersQueryValid = (browsers: string | Array<string>): boolean =>
   typeof browsers === "string" || Array.isArray(browsers);
 
-const semverMin = (first: ?string, second: string): string => {
+export const semverMin = (first: ?string, second: string): string => {
   return first && semver.lt(first, second) ? first : second;
 };
 
@@ -44,7 +44,16 @@ const getLowestVersions = (browsers: Array<string>): Targets => {
 
     try {
       // Browser version can return as "10.0-10.2"
-      const splitVersion = browserVersion.split("-")[0];
+      const splitVersion = browserVersion.split("-")[0].toLowerCase();
+
+      if (isUnreleasedVersion(splitVersion, browserName)) {
+        all[normalizedBrowserName] = getLowestUnreleased(
+          all[normalizedBrowserName],
+          splitVersion,
+          browserName,
+        );
+      }
+
       const parsedBrowserVersion = semverify(splitVersion);
 
       all[normalizedBrowserName] = semverMin(
@@ -76,7 +85,12 @@ const outputDecimalWarning = (decimalTargets: Array<Object>): void => {
 };
 
 const targetParserMap = {
-  __default: (target, value) => [target, semverify(value)],
+  __default: (target, value) => {
+    const version = isUnreleasedVersion(value, target)
+      ? value.toLowerCase()
+      : semverify(value);
+    return [target, version];
+  },
 
   // Parse `node: true` and `node: "current"` to version
   node: (target, value) => {

experimental/babel-preset-env/src/utils.js

@@ -1,6 +1,8 @@
 // @flow
 
 import semver from "semver";
+import unreleasedLabels from "../data/unreleased-labels";
+import { semverMin } from "./targets-parser";
 import type { Targets } from "./types";
 
 // Convert version to a semver value.
@@ -43,7 +45,8 @@ export const prettifyTargets = (targets: Targets): Object => {
   return Object.keys(targets).reduce((results, target) => {
     let value = targets[target];
 
-    if (typeof value === "string") {
+    const unreleasedLabel = unreleasedLabels[target];
+    if (typeof value === "string" && unreleasedLabel !== value) {
       value = prettifyVersion(value);
     }
 
@@ -52,6 +55,26 @@ export const prettifyTargets = (targets: Targets): Object => {
   }, {});
 };
 
+export const isUnreleasedVersion = (version: string, env: string): boolean => {
+  const unreleasedLabel = unreleasedLabels[env];
+  return (
+    unreleasedLabel && unreleasedLabel === version.toString().toLowerCase()
+  );
+};
+
+export const getLowestUnreleased = (
+  a: string,
+  b: string,
+  env: string,
+): string => {
+  const unreleasedLabel = unreleasedLabels[env];
+  const hasUnreleased = [a, b].some(item => item === unreleasedLabel);
+  if (hasUnreleased) {
+    return a === hasUnreleased ? b : a || b;
+  }
+  return semverMin(a, b);
+};
+
 export const filterStageFromList = (list: any, stageList: any) => {
   return Object.keys(list).reduce((result, item) => {
     if (!stageList[item]) {

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp-browsers/actual.js

@@ -0,0 +1,4 @@
+let n = { x, y, ...z };
+try {
+  throw 0;
+} catch {}

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp-browsers/expected.js

@@ -0,0 +1,9 @@
+let n = {
+  x,
+  y,
+  ...z
+};
+
+try {
+  throw 0;
+} catch {}

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp-browsers/options.json

@@ -0,0 +1,11 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "browsers": "safari tp"
+      },
+      "shippedProposals": true
+    }
+   ]
+  ]
+}

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp/actual.js

@@ -0,0 +1 @@
+let { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 };

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp/expected.js

@@ -0,0 +1,10 @@
+let {
+  x,
+  y,
+  ...z
+} = {
+  x: 1,
+  y: 2,
+  a: 3,
+  b: 4
+};

experimental/babel-preset-env/test/fixtures/preset-options/safari-tp/options.json

@@ -0,0 +1,10 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "safari": "tp"
+      },
+      "shippedProposals": true
+    }]
+  ]
+}

experimental/babel-preset-env/test/targets-parser.spec.js

@@ -39,6 +39,28 @@ describe("getTargets", () => {
       );
     });
 
+    it("works with TP versions", () => {
+      assert.deepEqual(
+        getTargets({
+          browsers: "safari tp",
+        }),
+        {
+          safari: "tp",
+        },
+      );
+    });
+
+    it("returns TP version in lower case", () => {
+      assert.deepEqual(
+        getTargets({
+          safari: "TP",
+        }),
+        {
+          safari: "tp",
+        },
+      );
+    });
+
     it("ignores invalid", () => {
       assert.deepEqual(
         getTargets({