[WIP] Add node's "engines" option

package.json

@@ -7,6 +7,12 @@
   "license": "MIT",
   "repository": "https://github.com/babel/babel-preset-env",
   "main": "lib/index.js",
+  "engines" : { 
+    "node" : ">= 0.10.0"
+  },
+  "devEngines" : { 
+    "node" : ">= 6"
+  },
   "scripts": {
     "build": "rimraf lib && babel src -d lib",
     "build-data": "node ./scripts/build-data.js",

src/config-utils.js

@@ -0,0 +1,135 @@
+import semver from "semver";
+import path from "path";
+import fs from "fs";
+import { getEnv, semverify } from "./utils";
+import pluginList from "../data/plugins.json";
+import builtInsList from "../data/built-ins.json";
+
+/* Resolving path depending on what type of path was passed (directory or file).
+   ../confg/ -> ../confg/package.json
+   ./index.js -> ./package.json */
+const resolvePackagePath = (packagePath = "") => {
+  return path.join(packagePath, "package.json");
+};
+
+// Just check wether the file exist.
+export const fileExist = file =>
+  fs.existsSync(file) && fs.statSync(file).isFile();
+
+const eachParent = (file, callback) => {
+  if (!file) return undefined;
+  let loc = path.resolve(file);
+  do {
+    const result = callback(loc);
+    if (typeof result !== "undefined") return result;
+  } while (loc !== (loc = path.dirname(loc)));
+  return undefined;
+};
+
+const parsePackage = path => JSON.parse(fs.readFileSync(path));
+
+export const findPackageRecursively = entry => {
+  return eachParent(entry, dir => {
+    const pkg = resolvePackagePath(dir);
+
+    if (fileExist(pkg)) {
+      try {
+        return parsePackage(pkg);
+      } catch (e) {
+        console.warn("Can't parse " + pkg + ".");
+      }
+    }
+  });
+};
+
+/* Filter versions that satisfiyng to passed semver range.
+   Ex: 5.5 satisfies ^5.0, 1.0.1 satisfies >= 1.0 */
+const filterSatisfiedVersions = (range, versions) => {
+  return versions.filter(targ => semver.satisfies(targ, range));
+};
+
+const getVersionsFromList = list => {
+  return Object.keys(list).reduce(
+    (allVersions, currentItem) => {
+      const currentVersions = list[currentItem];
+      for (const envName in currentVersions) {
+        const currentVersion = allVersions[envName];
+        const envVersion = currentVersions[envName];
+
+        if (!currentVersion) {
+          allVersions[envName] = [envVersion];
+        } else if (currentVersion.indexOf(envVersion) === -1) {
+          allVersions[envName].push(envVersion);
+        }
+      }
+
+      for (const env in allVersions) {
+        allVersions[env].sort((a, b) => a - b);
+      }
+
+      return allVersions;
+    },
+    {},
+  );
+};
+
+/* First, it checks whether passed version is a wildcat, a range or a simple string
+   - For wildcats(*) returs null. It means all node versions are matched.
+   - For versions in a simple string format (2.0) it converts it to the number.
+   - For ranged values (^4.5, ~2.1.0) it checks all versions we must support and returns lowest from the list.
+*/
+export const getLowestFromSemverValue = (version, versionsList) => {
+  if (version === "*") {
+    return null;
+  }
+
+  if (semver.valid(version)) {
+    return version;
+  } else if (semver.validRange(version)) {
+    const versions = versionsList.map(semverify);
+    const allSupported = filterSatisfiedVersions(version, versions);
+    if (allSupported.length) {
+      return allSupported[0];
+    }
+  }
+  return null;
+};
+
+/* Try to access `package.json` with passed path.
+   If can't - logs (but doesn't throw) an error. */
+export const getPackageJSON = packagePath => {
+  try {
+    return findPackageRecursively(packagePath);
+  } catch (e) {
+    console.warn(`Can't parse package.json in ${packagePath}: `, e);
+  }
+};
+
+/* Gives `package.json` path and all versions to consider and
+   returns engines/devEngines version or `null`.
+   `null` means support all node.js versions. */
+export const getEnginesNodeVersion = (packagePath, useBuiltIns) => {
+  const env = getEnv(process.env);
+  const pkg = getPackageJSON(packagePath);
+  if (!pkg) return null;
+  const engines = (env === "development" && pkg.devEngines) || pkg.engines;
+
+  if (engines && engines.node) {
+    const semverVersion = engines.node;
+
+    const list = [pluginList];
+    if (useBuiltIns) {
+      list.push(builtInsList);
+    }
+
+    const allSupportedVersions = getVersionsFromList(
+      Object.assign({}, ...list),
+    );
+
+    return getLowestFromSemverValue(
+      semverVersion,
+      allSupportedVersions["node"],
+    );
+  }
+  return null;
+};

src/index.js

@@ -100,11 +100,11 @@ function getPlatformSpecificDefaultFor(targets) {
   return isAnyTarget || isWebTarget ? defaultWebIncludes : [];
 }
 
-export default function buildPreset(context, opts = {}) {
+export default function buildPreset(context, opts = {}, fileContext) {
   const validatedOptions = normalizeOptions(opts);
   const { debug, loose, moduleType, useBuiltIns } = validatedOptions;
 
-  const targets = getTargets(validatedOptions.targets);
+  const targets = getTargets(validatedOptions.targets, opts, fileContext);
   const include = transformIncludesAndExcludes(validatedOptions.include);
   const exclude = transformIncludesAndExcludes(validatedOptions.exclude);
 

src/targets-parser.js

@@ -1,6 +1,7 @@
 import browserslist from "browserslist";
 import semver from "semver";
 import { semverify } from "./utils";
+import { getEnginesNodeVersion } from "./config-utils";
 
 const browserNameMap = {
   chrome: "chrome",
@@ -65,11 +66,15 @@ const outputDecimalWarning = decimalTargets => {
 const targetParserMap = {
   __default: (target, value) => [target, semverify(value)],
 
-  // Parse `node: true` and `node: "current"` to version
-  node: (target, value) => {
-    const parsed = value === true || value === "current"
-      ? process.versions.node
-      : semverify(value);
+  node: (target, value, options = {}, fileContext = {}) => {
+    let parsed;
+    if (value === true || value === "current") {
+      parsed = process.versions.node;
+    } else if (value === "engines") {
+      parsed = getEnginesNodeVersion(fileContext.dirname, options.useBuiltIns);
+    } else {
+      parsed = semverify(value);
+    }
 
     return [target, parsed];
   },
@@ -78,7 +83,7 @@ const targetParserMap = {
   uglify: (target, value) => [target, value === true],
 };
 
-const getTargets = (targets = {}) => {
+const getTargets = (targets = {}, options, fileContext) => {
   let targetOpts = {};
 
   // Parse browsers target via browserslist
@@ -99,7 +104,12 @@ const getTargets = (targets = {}) => {
 
         // Check if we have a target parser?
         const parser = targetParserMap[target] || targetParserMap.__default;
-        const [parsedTarget, parsedValue] = parser(target, value);
+        const [parsedTarget, parsedValue] = parser(
+          target,
+          value,
+          options,
+          fileContext,
+        );
 
         if (parsedValue) {
           // Merge (lowest wins)

src/utils.js

@@ -1,6 +1,7 @@
 // @flow
 import semver from "semver";
 
+const DEFAULT_ENV = "development";
 // Convert version to a semver value.
 // 2.5 -> 2.5.0; 1 -> 1.0.0;
 export const semverify = version => {
@@ -17,6 +18,10 @@ export const semverify = version => {
   return split.join(".");
 };
 
+export const desemverify = version => {
+  return parseFloat(version);
+};
+
 export const prettifyVersion = version => {
   if (typeof version !== "string") {
     return version;
@@ -52,3 +57,66 @@ export const prettifyTargets = (targets = {}) => {
     {},
   );
 };
+
+export const getEnv = env => {
+  return env.BABEL_ENV || env.NODE_ENV || DEFAULT_ENV;
+};
+
+// const DEFAULT_ENV = "development";
+// const filePathRe = /^(\.\w+)|(\w+\.\w+)$/;
+// const patchSpecifiedRe = /^\d+\.\d+\.\d+$/;
+
+// export const _extends = Object.assign || function (target) {
+//   for (let i = 1; i < arguments.length; i++) {
+//     const source = arguments[i];
+//     for (const key in source) {
+//       if (Object.prototype.hasOwnProperty.call(source, key)) {
+//         target[key] = source[key];
+//       }
+//     }
+//   }
+//   return target;
+// };
+
+// /* Convert version to a semver value.
+//   2.5 -> 2.5.0; 1 -> 1.0.0;
+// */
+// export const semverify = (version) => {
+//   if (typeof version === "string" && patchSpecifiedRe.test(version)) {
+//     return version;
+//   }
+//   const isInt = version % 1 === 0;
+//   const stringified = version.toString();
+//   const strEnd = isInt ? ".0.0" : ".0";
+//   return stringified + strEnd;
+// };
+
+//  Convert semver value to a number.
+//    Be careful when passing ranges! It's better to use `getLowestFromSemverValue` from config-utils.js
+
+// export const desemverify = (version) => {
+//   return parseFloat(version);
+// };
+
+// // Get current environment.
+
+// /* Check passed argument includes filename.
+//    Ex: ./.babelerc, /my/path/package.json
+// */
+// export const pathIsFile = (targetPath) => {
+//   return filePathRe.test(targetPath);
+// };
+
+// /* Recline filename for the given path.
+//    Ex: my/path/package.json -> my/path/
+// */
+// export const getDirnameInPath = (targetPath) => {
+//   return targetPath.substring(0, targetPath.lastIndexOf("/") + 1);
+// };
+
+// /* Pick filename for the given path.
+//    Ex: my/path/package.json -> package.json
+// */
+// export const getFilenameInPath = (targetPath) => {
+//   return targetPath.substring(targetPath.lastIndexOf("/") + 1);
+// };

test/fixtures/preset-options/dev-engines/actual.js

@@ -0,0 +1 @@
+const a = 1;

test/fixtures/preset-options/dev-engines/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+
+const a = 1;

test/fixtures/preset-options/dev-engines/options.json

@@ -0,0 +1,9 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "node": "engines"
+      }
+    }]
+  ]
+}

test/fixtures/preset-options/dev-engines/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "fixtures-dev-engines-test",
+  "engines" : {
+    "node" : ">= 0.10.0"
+  },
+  "devEngines" : {
+    "node" : ">= 6"
+  }
+}

test/fixtures/preset-options/engines/actual.js

@@ -0,0 +1 @@
+const a = 1;

test/fixtures/preset-options/engines/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+
+var a = 1;

test/fixtures/preset-options/engines/options.json

@@ -0,0 +1,9 @@
+{
+  "presets": [
+    ["../../../../lib", {
+      "targets": {
+        "node": "engines"
+      }
+    }]
+  ]
+}

test/fixtures/preset-options/engines/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "fixtures-dev-engines-test",
+  "engines" : {
+    "node" : ">= 0.10.0"
+  }
+}