feat(extendsMappedType): make sure extending mapped types do not prevent to compile

src/transformer/descriptor/mock/mockProperties.ts

@@ -8,7 +8,9 @@ import { PropertyLike } from './propertyLike';
 import { SignatureLike } from './signatureLike';
 
 export function GetMockPropertiesFromSymbol(propertiesSymbol: ts.Symbol[], signatures: ReadonlyArray<ts.Signature>, scope: Scope): ts.Expression {
-  const properties: PropertyLike[] = propertiesSymbol.map((prop: ts.Symbol) => prop.declarations[0]) as PropertyLike[];
+  const properties: PropertyLike[] = propertiesSymbol
+    .filter((prop: ts.Symbol) => !!prop.declarations) // Dynamically generated properties (mapped types) do not have declarations
+    .map((prop: ts.Symbol) => prop.declarations[0]) as PropertyLike[];
 
   const signaturesDeclarations: SignatureLike[] = signatures.map((signature: ts.Signature) => signature.declaration) as SignatureLike[];
 

test/transformer/descriptor/extends/mappedTypes.test.ts

@@ -0,0 +1,22 @@
+import {createMock} from 'ts-auto-mock';
+
+describe('extends MappedTypes', () => {
+  it('should not convert the properties', () => {
+    enum SOME_ENUM {
+      FIRST = 'FIRST',
+      SECOND = 'SECOND',
+    }
+
+
+    interface IBase {
+      propertyA: string;
+      propertyB: number;
+    }
+
+    interface InterfaceWithExtends extends Record<SOME_ENUM, IBase> {}
+
+    const type: InterfaceWithExtends = createMock<InterfaceWithExtends>();
+    expect(type.FIRST).toBeUndefined();
+    expect(type.SECOND).toBeUndefined();
+  });
+});

ui/src/views/types-not-supported.mdx

@@ -42,3 +42,32 @@ Object.getOwnPropertySymbols(mock); //it should return the symbol testSymbol
 ```
 
 TsAutoMock will create a property with the random name generated by typescript (example __@aSymbol) instead of the correct symbol.
+
+## Extends Mapped Type
+```ts
+
+enum SOME_ENUM {
+    FIRST = 'FIRST',
+    SECOND = 'SECOND',
+}
+
+interface IBase {
+    someField: string;
+    anotherField: number;
+}
+
+interface InterfaceWithExtendsMappedType extends Record<SOME_ENUM, IBase[]> {}
+
+const mock = createMock<InterfaceWithExtendsMappedType>();
+
+mock.FIRST // undefined, it should be IBase[]
+mock.SECOND // undefined, it should be IBase[]
+
+[issue](https://github.com/Typescript-TDD/ts-auto-mock/issues/238)
+Unfortunately this functionality doesnt work yet because when getting properties from an interface that extend
+a mapped type typescript returns a different type of property that is difficult to mock.
+
+There is a branch created with a working version but it needs more investigation because the implementation is not readable and it may cause more issues
+[link](https://github.com/Typescript-TDD/ts-auto-mock/tree/feature/extends-mapped-type)
+
+```