"Strict" flag to override error in production environment

lib/generateConfig.js

@@ -5,7 +5,7 @@ const { promises: fsp } = require('fs');
 
 const runtimeConfig = {};
 
-async function generateConfig({ envConfig, envFile }) {
+async function generateConfig({ envConfig, envFile, strict = null }) {
   let envConfigExists = true;
 
   try {
@@ -25,6 +25,7 @@ async function generateConfig({ envConfig, envFile }) {
     throw err;
   }
 
+  const isRelaxed = strict == null ? process.env.NODE_ENV === recConstants.DEVELOPMENT : !strict;
   const content = await fsp.readFile(envFile, 'utf8');
 
   content.split(/\r?\n/)
@@ -33,12 +34,13 @@ async function generateConfig({ envConfig, envFile }) {
       const equalSignIndex = line.indexOf('=');
       const lengthOfString = line.length;
 
+
       if (equalSignIndex !== -1) {
         const key = line.slice(0, equalSignIndex);
         const value = line.slice(equalSignIndex + 1, lengthOfString);
 
-        if (process.env.NODE_ENV === recConstants.DEVELOPMENT) {
-          runtimeConfig[key] = value;
+        if (isRelaxed) {
+          runtimeConfig[key] = process.env[key] ?? value;
         } else {
           if (!process.env[key])
             throw new Error(`Error getting '${key}' from process.env`);

lib/index.js

@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+
 const yargs = require('yargs');
 
 const generateConfig = require('./generateConfig');
@@ -17,6 +18,11 @@ const argv = yargs
     description: 'Location and name of your .env file.',
     default: './.env',
     type: 'string',
+  }).option('strict', {
+    alias: 's',
+    'description': "Raise error if matching environment variables for .env variable",
+    'default': null,
+    'type': 'boolean'
   })
   .help()
   .alias('help', 'h').argv;
@@ -25,11 +31,13 @@ const argv = yargs
   try {
     const envConfig = argv['config-name'];
     const envFile = argv['env-file'];
+    const strict = argv['strict'];
 
     console.log(`
   Provided flags:
     --config-name = ${envConfig}
     --env-file = ${envFile}
+    --strict = ${strict}
 
   Your environment variables will be available on '${constants.runtimeConfigPath}'
   `);
@@ -40,6 +48,7 @@ const argv = yargs
       result = await generateConfig({
         envConfig,
         envFile,
+        strict
       });
     } catch (err) {
       throw new Error(err.message);

tests/generateConfig.spec.js

@@ -66,8 +66,50 @@ describe('runtime-env-cra', () => {
     );
   });
 
-  it('should throw error if NODE_ENV is production and env var is not found in shell', async () => {
+  it('should throw error if NODE_ENV is production, env var is not found in shell, and strict is not set', async () => {
     process.env.NODE_ENV = 'production';
+    let config;
+    let error;
+
+    try {
+      config = await generateConfig({
+        envConfig: './tests/utils/runtime-config.js',
+        envFile: './tests/utils/.env',
+      });
+    } catch (err) {
+      error = err;
+    }
+
+    expect(config).toBeUndefined();
+    expect(error).toBeDefined();
+    expect(error.message).toEqual('Error getting \'TEST_VAR\' from process.env');
+  });
+
+  it('should default to env if NODE_ENV is production, env var is not found in shell, and strict is set to false', async () => {
+    process.env.NODE_ENV = 'production';
+
+    let config;
+    let error;
+
+    try {
+      config = await generateConfig({
+        envConfig: './tests/utils/runtime-config.js',
+        envFile: './tests/utils/.env',
+        strict: false
+      });
+    } catch (err) {
+      error = err;
+    }
+
+    expect(error).toBeUndefined();
+    expect(config).toBeDefined();
+    expect(config).toEqual(
+      'window.__RUNTIME_CONFIG__ = {"TEST_VAR":"TEST_VALUE"};',
+    );
+  });
+
+  it('should throw error if env var is not found in shell, and strict is true regardless of environment', async () => {
+    process.env.NODE_ENV = 'development';
 
     let config;
     let error;
@@ -76,6 +118,7 @@ describe('runtime-env-cra', () => {
       config = await generateConfig({
         envConfig: './tests/utils/runtime-config.js',
         envFile: './tests/utils/.env',
+        strict: true
       });
     } catch (err) {
       error = err;
@@ -86,6 +129,22 @@ describe('runtime-env-cra', () => {
     expect(error.message).toEqual('Error getting \'TEST_VAR\' from process.env');
   });
 
+  it('should generate a runtime-config.js file successfully on Production', async () => {
+    process.env.NODE_ENV = 'Production';
+    process.env.TEST_VAR = 'TEST_VALUE';
+
+
+    config = await generateConfig({
+      envConfig: './tests/utils/runtime-config.js',
+      envFile: './tests/utils/.env',
+    });
+
+    expect(config).toBeDefined();
+    expect(config).toEqual(
+      'window.__RUNTIME_CONFIG__ = {"TEST_VAR":"TEST_VALUE"};',
+    );
+  });
+
   it('should parse the TEST_VAR value from the shell when NODE_ENV is not set to development', async () => {
     process.env.TEST_VAR = 'TEST_VALUE';