feat(node-api): add noExport option

README.md

@@ -20,6 +20,7 @@ Takes the suck out of launching your server with various sets of environment var
   + [Exporting Values](#exporting-values)
   + [Options](#options)
   + [Example](#example)
+  + [Node.js API](#node-js-api)
 
 ## Intro
 
@@ -183,3 +184,37 @@ test
 foobar
 ```
 
+### Node.js API
+
+```js
+declare function defaultEnv(files: Array<string>, options: {
+  force?: boolean,
+  print?: boolean,
+  dotenv?: boolean,
+  noExport?: boolean,
+})
+```
+
+```js
+var path = require('path')
+var defaultEnv = require('defaultEnv')
+
+var defaults = defaultEnv([path.resolve('foo.js')], {noExport: true})
+```
+
+#### Options
+
+#### `force`
+If true, overwrite existing values for environment variables (by default, existing values will be preserved)
+**This does not currently apply to variables loaded via `--dotenv` option.**
+
+#### `print`
+See [Exporting Values](#exporting-values)
+
+#### `dotenv`
+If true, also loads variables from a .env file in the root directory of your project
+(by using `require('dotenv').config()`)
+
+##### `noExport`
+If true, doesn't write to `process.env`; only returns the values that would be written.
+

lib/index.js

@@ -32,13 +32,15 @@ function defaultEnv(envFiles, options) {
     }
     for (key in defaultValues) {
       if (!setvars.hasOwnProperty(key) && (!process.env.hasOwnProperty(key) || options.force || options.print)) {
-        process.env[key] = setvars[key] = defaultValues[key]
+        setvars[key] = defaultValues[key]
+        if (!options.noExport) process.env[key] = defaultValues[key]
       }
     }
   }
   if (options.print) {
     for (key in setvars) console.log('export ' + key + '=' + setvars[key]) // eslint-disable-line no-console
   }
+  return setvars
 }
 
 function run(command, args) {

lib/index.js.flow

@@ -1,5 +1,12 @@
 // @flow
 
-declare function defaultEnv(envFiles: Array<string>): void;
+export type Options = {
+  force?: boolean,
+  dotenv?: boolean,
+  print?: boolean,
+  noExport?: boolean,
+}
+
+declare function defaultEnv(envFiles: Array<string>, options: Options): {[varname: string]: string};
 declare module.exports: typeof defaultEnv;
 

test/index.js

@@ -8,11 +8,17 @@ var root = path.resolve(__dirname, '..')
 
 describe('defaultenv', function () {
   this.timeout(5000)
-  it('exports defaultEnv function', function () {
-    expect(process.env.FOO).not.to.exist
-    defaultEnv([path.resolve(__dirname, 'foo.env')])
-    expect(process.env.FOO).to.equal('foo')
-    delete process.env.FOO
+  describe('node.js API', function () {
+    it('puts vars on process.env unless noExport is true', function () {
+      expect(process.env.FOO).not.to.exist
+      defaultEnv([path.resolve(__dirname, 'foo.env')])
+      expect(process.env.FOO).to.equal('foo')
+      delete process.env.FOO
+
+      var vars = defaultEnv([path.resolve(__dirname, 'bar.env')], {noExport: true})
+      expect(process.env.BAR).not.to.exist
+      expect(vars.BAR).to.equal('bar')
+    })
   })
   it('prints usage and exits with no args', function (done) {
     var command = process.argv[0] + ' lib/index.js'