feat(helpers): add support and tests for complex intermediate return …

…types in fake method

src/modules/helpers/index.ts

@@ -1190,6 +1190,7 @@ export class HelpersModule {
 
     // split the method into module and function
     const parts = method.split('.');
+    const property = parts.length === 3 ? parts.pop() : undefined;
 
     let currentModuleOrMethod: unknown = this.faker;
     let currentDefinitions: unknown = this.faker.rawDefinitions;
@@ -1231,7 +1232,11 @@ export class HelpersModule {
       params = [parameters];
     }
 
-    const result = String(fn(...params));
+    const fnResult = fn(...params);
+    const result =
+      typeof fnResult === 'object' && property
+        ? String(fnResult[property as keyof typeof fnResult])
+        : String(fnResult);
 
     // Replace the found tag with the returned fake value
     // We cannot use string.replace here because the result might contain evaluated characters

test/modules/helpers.spec.ts

@@ -1150,6 +1150,29 @@ describe('helpers', () => {
         it('should not trim whitespace', () => {
           expect(faker.helpers.fake('   ---   ')).toBe('   ---   ');
         });
+
+        it('should be able to handle methods that return a complex object', () => {
+          expect(
+            faker.definitions.airline.airport.map((airport) => airport.iataCode)
+          ).toContain(faker.helpers.fake('{{airline.airport.iataCode}}'));
+        });
+
+        it('should return undefined if a method returns a complex object but the property is undefined', () => {
+          expect(faker.helpers.fake('{{airline.airport.code}}')).toBe(
+            'undefined'
+          );
+        });
+
+        it('should be able to pass multiple dynamic templates with complex objects', () => {
+          expect(
+            faker.definitions.airline.airplane.map((airplane) => airplane.name)
+          ).toContain(
+            faker.helpers.fake([
+              '{{airline.airplane.name}}',
+              '{{airline.airplane.name}}',
+            ])
+          );
+        });
       });
 
       describe('rangeToNumber()', () => {