Add ability to require string array of env vars & throwing the requir…

…ed vars

README.md

@@ -8,6 +8,7 @@ A micro-module to ensure your Node process env has all the necessary variables t
 * Make some config keys optional
 * Default values for keys
 * Nested objects in config
+* Multiple configuration files supported
 
 ## Example usage
 
@@ -46,3 +47,50 @@ if (missingConfigVars.length > 0) {
 
 // ... app logic
 ```
+
+### Directly throw if an error
+
+```javascript
+import { throwMissingConfigVars } from '@jazmon/require-env-vars';
+import config from './config';
+// You can pass multiple config files
+import fooConfig from './config/foo';
+
+try {
+  throwMissingConfigVars(config, fooConfig);
+} catch (err) {
+  console.error(err);
+  process.exit(2);
+}
+```
+
+## Example usage to require strings
+
+Or you can use the `requireEnvVars` which will take an array of strings as input to check env against:
+
+```javascript
+import { requireEnvVars } from '@jazmon/require-env-vars';
+
+const missingEnvVars = requireEnvVars(['API_KEY', 'API_URL']);
+
+if (missingEnvVars.length > 0) {
+  throw new Error(
+    `Required configuration variables are missing! ${JSON.stringify(
+      missingEnvVars,
+    )}`,
+  );
+  process.exit(2);
+}
+```
+
+### Directly throw if an error for string array
+
+```javascript
+import { throwMissingEnvVars } from '@jazmon/require-env-vars';
+try {
+  throwMissingEnvVars(['API_KEY', 'API_URL']);
+} catch (err) {
+  console.error(err);
+  process.exit(2);
+}
+```

src/index.spec.ts

@@ -1,4 +1,11 @@
-import { requireConfigKeys, requireConfigVars, Config } from './index';
+import {
+  requireConfigKeys,
+  requireConfigVars,
+  Config,
+  requireEnvVars,
+  throwMissingConfigVars,
+  throwMissingEnvVars,
+} from './index';
 
 let originalEnv: NodeJS.ProcessEnv;
 
@@ -147,3 +154,57 @@ describe('requireConfigVars', () => {
     expect(missingEnvVars).toContain('BAR');
   });
 });
+
+describe('throwMissingConfigVars', () => {
+  it('should throw if some variables are not in env', () => {
+    process.env = {
+      FOO: 'foo',
+      BAR: 'bar',
+    };
+    const config: Config = {
+      FOO: process.env.FOO as string,
+      FOO2: process.env.FOO2 as string,
+      NESTED: {
+        BAR: process.env.BAR as string,
+        BAR2: process.env.BAR2 as string,
+      },
+      BAZ: 'baz',
+    };
+    const testFn = () => {
+      throwMissingConfigVars(config);
+    };
+    expect(testFn).toThrowError();
+  });
+});
+
+describe('requireEnvVars', () => {
+  it('should require env vars', () => {
+    process.env = {
+      FOO: 'foo',
+    };
+    const config: Config = {
+      FOO: process.env.FOO,
+      BAR: process.env.BAR,
+    };
+    const missingEnvVars = requireEnvVars(['FOO', 'BAR']);
+    expect(missingEnvVars).toHaveLength(1);
+    expect(missingEnvVars).toContain('BAR');
+  });
+});
+
+describe('throwMissingEnvVars', () => {
+  it('should throw required env vars', () => {
+    process.env = {
+      FOO: 'foo',
+    };
+    const config: Config = {
+      FOO: process.env.FOO,
+      BAR: process.env.BAR,
+    };
+
+    const testFn = () => {
+      throwMissingEnvVars(['FOO', 'BAR']);
+    };
+    expect(testFn).toThrowError();
+  });
+});

src/index.ts

@@ -28,4 +28,35 @@ export const requireConfigVars = (...configs: Config[]): string[] => {
   );
 };
 
+export const throwMissingConfigVars = (...configs: Config[]) => {
+  const missingConfigVars = requireConfigVars(...configs);
+  if (missingConfigVars.length > 0) {
+    throw new Error(
+      `Rerquired environment variables are not defined! ${JSON.stringify(
+        missingConfigVars,
+      )}`,
+    );
+  }
+};
+
+export const requireEnvVars = (envVars: string[]) => {
+  const missingEnvVars: string[] = [];
+  envVars.forEach(envVar => {
+    if (process.env[envVar] === undefined) {
+      missingEnvVars.push(envVar);
+    }
+  });
+  return missingEnvVars;
+};
+
+export const throwMissingEnvVars = (envVars: string[]) => {
+  const missingEnvVars = requireEnvVars(envVars);
+  if (missingEnvVars.length > 0)
+    throw new Error(
+      `Required enviroment variables are not defined! ${JSON.stringify(
+        missingEnvVars,
+      )}`,
+    );
+};
+
 export default requireConfigVars;