refactor(get-env-value): rewrite the function

packages/get-env-value/src/main.ts

@@ -3,25 +3,42 @@ import {platformInfo} from '@alwatr/platform-info';
 
 __dev_mode__: packageTracer.add(__package_name__, __package_version__);
 
-interface GetEnvValueParams {
+/**
+ * Parameters for retrieving an environment variable value.
+ */
+export type GetEnvValueParams = {
+  /**
+   * The name of the environment variable.
+   */
   name: string;
+
+  /**
+   * The default value to use if the environment variable is not set.
+   * If not provided, the environment variable is required and an error will be thrown if it is not set.
+   * Except in development mode, where the development value will be used instead if provided.
+   */
   defaultValue?: string;
+
+  /**
+   * The value to use in a development environment.
+   * It will be overwrite the default value in development mode and completely ignored in production mode.
+   */
   developmentValue?: string;
 }
 
-export function getEnvValue(params: GetEnvValueParams): string {
-  if (platformInfo.development === true) {
-    const value = params.developmentValue ?? params.defaultValue;
-    if (value === undefined) {
-      throw new Error(`Set default value or development value for ${params.name} while you are developing.`);
-    }
+export function getEnvValue(option: GetEnvValueParams): string {
+  let value = process.env[option.name];
+  if (value === '') value = undefined; // empty string is considered as undefined in environment variables
 
-    return value;
+  value ??= option.defaultValue;
+
+  if (platformInfo.development === true) {
+    value ??= option.developmentValue;
   }
 
-  if (process.env[params.name] === undefined || process.env[params.name] === '') {
-    throw new Error(`${params.name} is a required ENV key in production.`);
+  if (value === undefined) {
+    throw new Error(`Environment variable "${option.name}" is required.`);
   }
 
-  return process.env[params.name]!;
+  return value;
 }