Expose the envName as a programmatic and CLI option.

packages/babel-cli/src/babel/index.js

@@ -49,6 +49,11 @@ commander.option(
   collect,
 );
 commander.option("--config-file [path]", "Path a to .babelrc file to use");
+commander.option(
+  "--env-name [name]",
+  "The name of the 'env' to use when loading configs and plugins. " +
+    "Defaults to the value of BABEL_ENV, or else NODE_ENV, or else 'development'.",
+);
 
 // Basic file input configuration.
 commander.option("--source-type [script|module]", "");

packages/babel-core/README.md

@@ -144,10 +144,11 @@ Following is a table of the options you can use:
 | `auxiliaryCommentAfter`  | `null`               | Attach a comment after all non-user injected code |
 | `auxiliaryCommentBefore` | `null`               | Attach a comment before all non-user injected code |
 | `babelrc`                | `true`               | Specify whether or not to use .babelrc and .babelignore files. Not available when using the CLI, [use `--no-babelrc` instead](https://babeljs.io/docs/usage/cli/#babel-ignoring-babelrc) |
+| `envName`                | env vars             | Defaults to environment variable `BABEL_ENV` if set, or else `NODE_ENV` if set, or else it defaults to `"development"` |
 | `code`                   | `true`               | Enable code generation |
 | `comments`               | `true`               | Output comments in generated output |
 | `compact`                | `"auto"`             | Do not include superfluous whitespace characters and line terminators. When set to `"auto"` compact is set to `true` on input sizes of >500KB |
-| `env`                    | `{}`                 | This is an object of keys that represent different environments. For example, you may have: `{ env: { production: { /* specific options */ } } }` which will use those options when the environment variable `BABEL_ENV` is set to `"production"`. If `BABEL_ENV` isn't set then `NODE_ENV` will be used, if it's not set then it defaults to `"development"` |
+| `env`                    | `{}`                 | This is an object of keys that represent different environments. For example, you may have: `{ env: { production: { /* specific options */ } } }` which will use those options when the `envName` is `production` |
 | `extends`                | `null`               | A path to a `.babelrc` file to extend |
 | `filename`               | `"unknown"`          | Filename for use in errors etc |
 | `filenameRelative`       | `(filename)`         | Filename relative to `sourceRoot` |

packages/babel-core/src/config/option-manager.js

@@ -103,7 +103,7 @@ class OptionManager {
   init(inputOpts: {}) {
     const args = validate("arguments", inputOpts);
 
-    const envName = getEnv();
+    const { envName = getEnv() } = args;
 
     const configChain = buildConfigChain(args, envName);
     if (!configChain) return null;
@@ -133,6 +133,7 @@ class OptionManager {
       .filter(plugins => plugins.length > 0)
       .map(plugins => ({ plugins }));
     opts.passPerPreset = opts.presets.length > 0;
+    opts.envName = envName;
 
     return {
       options: opts,

packages/babel-core/src/config/options.js

@@ -28,6 +28,10 @@ const ROOT_VALIDATORS: ValidatorSet = {
   >),
   code: (assertBoolean: Validator<$PropertyType<ValidatedOptions, "code">>),
   ast: (assertBoolean: Validator<$PropertyType<ValidatedOptions, "ast">>),
+
+  envName: (assertString: Validator<
+    $PropertyType<ValidatedOptions, "envName">,
+  >),
 };
 
 const NONPRESET_VALIDATORS: ValidatorSet = {
@@ -130,6 +134,7 @@ export type ValidatedOptions = {
   code?: boolean,
   ast?: boolean,
   inputSourceMap?: RootInputSourceMapOption,
+  envName?: string,
 
   extends?: string,
   env?: EnvSet<ValidatedOptions>,