Merge pull request #5448 from xtuc/feat-expose-env-core

Export Babel's environment

packages/babel-core/src/helpers/environment.js

@@ -0,0 +1,6 @@
+export function getEnv(defaultValue = "development") {
+
+  return process.env.BABEL_ENV
+    || process.env.NODE_ENV
+    || defaultValue;
+}

packages/babel-core/src/index.js

@@ -6,7 +6,9 @@ export { default as buildExternalHelpers } from "./tools/build-external-helpers"
 export { default as template } from "babel-template";
 export { default as resolvePlugin } from "./helpers/resolve-plugin";
 export { default as resolvePreset } from "./helpers/resolve-preset";
+
 export { version } from "../package";
+export { getEnv } from "./helpers/environment";
 
 import * as util from "./util";
 export { util };

packages/babel-core/src/transformation/file/options/build-config-chain.js

@@ -1,3 +1,4 @@
+import * as babel from "../../../index";
 import resolve from "../../../helpers/resolve";
 import json5 from "json5";
 import path from "path";
@@ -195,7 +196,8 @@ class ConfigChainBuilder {
 
     // env
     let envOpts;
-    const envKey = process.env.BABEL_ENV || process.env.NODE_ENV || "development";
+
+    const envKey = babel.getEnv();
     if (options.env) {
       envOpts = options.env[envKey];
       delete options.env;

packages/babel-register/src/node.js

@@ -56,7 +56,8 @@ function compile(filename) {
 
   let cacheKey = `${JSON.stringify(opts)}:${babel.version}`;
 
-  const env = process.env.BABEL_ENV || process.env.NODE_ENV;
+  const env = babel.getEnv(false);
+
   if (env) cacheKey += `:${env}`;
 
   if (cache) {