feat(config): add tests for environment variable placeholder replacement

Author: jase88

apps/generator-cli/src/app/services/config.service.spec.ts

@@ -94,7 +94,11 @@ describe('ConfigService', () => {
     });
 
     describe('the config has values having placeholders', () => {
+      let originalEnv: NodeJS.ProcessEnv;
+
       beforeEach(() => {
+        originalEnv = { ...process.env };
+        
         fs.readJSONSync.mockReturnValue({
           $schema: 'foo.json',
           spaces: 4,
@@ -111,19 +115,16 @@ describe('ConfigService', () => {
       });
 
       afterEach(() => {
-        delete process.env['__unit_test_username'];
-        delete process.env['__unit_test_password'];
-      })
+        process.env = { ...originalEnv };
+      });
 
       it('verify placeholder replaced with env vars', () => {
         const value = fixture.get('generator-cli.repository.queryUrl');
-
         expect(value).toEqual('https://myusername:mypassword@server/api');
       });
 
       it('verify placeholders not matching env vars are not replaced', () => {
         const value = fixture.get('generator-cli.repository.downloadUrl');
-
         expect(value).toEqual('https://${env.__unit_test_non_matching}@server/api');
         expect(error).toHaveBeenCalledWith('Environment variable for placeholder \'__unit_test_non_matching\' not found.');
       });
@@ -221,5 +222,60 @@ describe('ConfigService', () => {
         });
       });
     });
+
+    describe('replacePlaceholders', () => {
+      let originalEnv: NodeJS.ProcessEnv;
+
+      beforeEach(() => {
+        jest.clearAllMocks();
+        originalEnv = { ...process.env };
+      });
+
+      afterEach(() => {
+        process.env = { ...originalEnv };
+      });
+
+      it('replaces a simple placeholder with an environment variable', () => {
+        process.env.TEST_VAR = 'value1';
+        const input = { key: 'Hello ${TEST_VAR}' };
+        const result = fixture['replacePlaceholders'](input);
+        expect(result.key).toBe('Hello value1');
+      });
+
+      it('leaves placeholder unchanged and logs error if env var is missing', () => {
+        delete process.env.MISSING_VAR;
+        const input = { key: 'Hello ${MISSING_VAR}' };
+        const result = fixture['replacePlaceholders'](input);
+        expect(result.key).toBe('Hello ${MISSING_VAR}');
+        expect(error).toHaveBeenCalledWith(expect.stringContaining('MISSING_VAR'));
+      });
+
+      it('replaces placeholders in nested objects and arrays', () => {
+        process.env.NESTED_VAR = 'nested';
+        const input = {
+          arr: ['${NESTED_VAR}', { inner: '${NESTED_VAR}' }],
+          obj: { deep: '${NESTED_VAR}' },
+        };
+        const result = fixture['replacePlaceholders'](input);
+        expect(result.arr[0]).toBe('nested');
+        expect((result.arr[1] as { inner: string }).inner).toBe('nested');
+        expect((result.obj as { deep: string }).deep).toBe('nested');
+      });
+
+      it('handles env. prefix in placeholders', () => {
+        process.env.PREFIX_VAR = 'prefix';
+        const input = { key: 'Value: ${env.PREFIX_VAR}' };
+        const result = fixture['replacePlaceholders'](input);
+        expect(result.key).toBe('Value: prefix');
+      });
+
+      it('replaces multiple placeholders in a single string', () => {
+        process.env.FIRST = 'one';
+        process.env.SECOND = 'two';
+        const input = { key: 'Values: ${FIRST}, ${SECOND}' };
+        const result = fixture['replacePlaceholders'](input);
+        expect(result.key).toBe('Values: one, two');
+      });
+    });
   });
 });

apps/generator-cli/src/app/services/config.service.ts

@@ -76,7 +76,7 @@ export class ConfigService {
         return Object.prototype.hasOwnProperty.call(obj, head);
       }
 
-      return hasPath((obj as Record<string, unknown>)[head] as Record<string, unknown> | undefined, tail);
+      return hasPath(obj[head] as Record<string, unknown>, tail);
     };
 
     return hasPath(this.read(), path.split('.'));
@@ -148,10 +148,9 @@ export class ConfigService {
   private replacePlaceholders(config: Record<string, unknown>): Record<string, unknown> {
     const replacePlaceholderInString = (inputString: string): string => {
       return inputString.replace(/\${(.*?)}/g, (fullMatch, placeholderKey) => {
-        const trimmedKey = placeholderKey.trim();
-        const environmentVariableKey = trimmedKey.startsWith('env.')
-          ? trimmedKey.substring(4)
-          : trimmedKey;
+        const environmentVariableKey = placeholderKey.startsWith('env.')
+          ? placeholderKey.substring(4)
+          : placeholderKey;
 
         const environmentVariableValue = process.env[environmentVariableKey];