(#133) Add option allowEmptyValues

README.md

@@ -92,6 +92,7 @@ Use the following properties to configure your instance.
 
 * **path** (`'./.env'`) - The path to your environment variables.
 * **safe** (`false`) - If true, load '.env.example' to verify the '.env' variables are all set. Can also be a string to a different file.
+* **allowEmptyValues** (`false`) - Whether to allow empty strings in safe mode. If false, will throw an error if any env variables are empty (but only if safe mode is enabled).
 * **systemvars** (`false`) - Set to true if you would rather load all system variables as well (useful for CI purposes).
 * **silent** (`false`) - If true, all warnings will be suppressed.
 * **expand** (`false`) - Allows your variables to be "expanded" for reusability within your `.env` file.
@@ -106,6 +107,7 @@ module.exports = {
     new Dotenv({
       path: './some.other.env', // load this now instead of the ones in '.env'
       safe: true, // load '.env.example' to verify the '.env' variables are all set. Can also be a string to a different file.
+      allowEmptyValues: true, // allow empty variables (e.g. `FOO=`) (treat it as empty string, rather than missing)
       systemvars: true, // load all the predefined 'process.env' variables which will trump anything local per dotenv specs.
       silent: true, // hide any errors
       defaults: false // load '.env.defaults' as the default values if empty.

src/index.js

@@ -48,14 +48,18 @@ class Dotenv {
   }
 
   gatherVariables () {
-    const { safe } = this.config
+    const { safe, allowEmptyValues } = this.config
     const vars = this.initializeVars()
 
     const { env, blueprint } = this.getEnvs()
 
     Object.keys(blueprint).map(key => {
       const value = Object.prototype.hasOwnProperty.call(vars, key) ? vars[key] : env[key]
-      if (!value && safe) {
+
+      const isMissing = typeof value === 'undefined' || value === null ||
+        (!allowEmptyValues && value === '')
+
+      if (safe && isMissing) {
         throw new Error(`Missing environment variable: ${key}`)
       } else {
         vars[key] = value

test/envs/.missingone

@@ -1,2 +1 @@
-TEST=
 TEST2=Hello

test/envs/.oneempty

@@ -0,0 +1,2 @@
+TEST=
+TEST2=Hello

test/envs/.oneempty.example

@@ -0,0 +1,2 @@
+TEST=
+TEST2=

test/main.spec.js

@@ -13,6 +13,8 @@ const envEmpty = path.resolve(__dirname, './envs/.empty')
 const envEmptyExample = path.resolve(__dirname, './envs/.empty.example')
 const envSimple = path.resolve(__dirname, './envs/.simple')
 const envSimpleExample = path.resolve(__dirname, './envs/.simple.example')
+const envOneEmpty = path.resolve(__dirname, './envs/.oneempty')
+const envOneEmptyExample = path.resolve(__dirname, './envs/.oneempty.example')
 const envMissingOne = path.resolve(__dirname, './envs/.missingone')
 const envMissingOneExample = path.resolve(__dirname, './envs/.missingone.example')
 const envSystemvars = path.resolve(__dirname, './envs/.systemvars')
@@ -28,7 +30,8 @@ const buildExpectation = (obj) => Object.keys(obj).reduce((all, key) => {
 const envDefJson = buildExpectation({ TEST: 'hi' })
 const envEmptyJson = buildExpectation({})
 const envSimpleJson = buildExpectation({ TEST: 'testing' })
-const envMissingOneJson = buildExpectation({ TEST: '', TEST2: 'Hello' })
+const envOneEmptyJson = buildExpectation({ TEST: '', TEST2: 'Hello' })
+const envMissingOneJson = buildExpectation({ TEST2: 'Hello' })
 const envDefaultsJson = buildExpectation({ TEST: 'hi', TEST2: 'hidefault' })
 const envDefaultsJson2 = buildExpectation({ TEST: 'hi', TEST2: 'youcanseethis' })
 
@@ -208,12 +211,30 @@ function runTests (Obj, name) {
       })
     })
 
+    describe('Empty variables', () => {
+      it('Should load fine (not-safe)', () => {
+        envTest({ path: envOneEmpty }).should.deep.equal(envOneEmptyJson)
+      })
+
+      it('Should fail on safe mode', () => {
+        function errorTest () {
+          envTest({ path: envOneEmpty, safe: envOneEmptyExample })
+        }
+
+        errorTest.should.throw('Missing environment variable')
+      })
+
+      it('Should succeed in safe mode if allowEmptyValues is true', () => {
+        envTest({ path: envOneEmpty, safe: envOneEmptyExample, allowEmptyValues: true }).should.deep.equal(envOneEmptyJson)
+      })
+    })
+
     describe('Missing a variable', () => {
       it('Should load fine (not-safe)', () => {
         envTest({ path: envMissingOne }).should.deep.equal(envMissingOneJson)
       })
 
-      it('Should fail on safe mode', () => {
+      it('Should fail on safe mode (if allowEmptyValues is false)', () => {
         function errorTest () {
           envTest({ path: envMissingOne, safe: envMissingOneExample })
         }