Don't try to add an implicit undefined for mapped properties outside of strictNullChecks (#60393)

tests/cases/compiler/declarationEmitOptionalMappedTypePropertyNoStrictNullChecks1.ts

@@ -0,0 +1,30 @@
+// @strictNullChecks: false
+// @declaration: true
+// @emitDeclarationOnly: true
+
+// @filename: createApi.ts
+
+type Id<T> = {
+  [K in keyof T]: T[K];
+} & {};
+
+export declare function createApi<Definitions>(_: { endpoints: Definitions }): {
+  [K in keyof Definitions as `use${Capitalize<K & string>}Query`]: () => Id<{
+    status: "uninitialized";
+    originalArgs?: undefined;
+  }>;
+};
+
+// @filename: index.ts
+
+import { createApi } from "./createApi";
+
+const slice = createApi({
+  endpoints: {
+    test: {
+      url: `/user`,
+    },
+  },
+});
+
+export const { useTestQuery } = slice;

tests/cases/compiler/declarationEmitOptionalMappedTypePropertyNoStrictNullChecks2.ts

@@ -0,0 +1,30 @@
+// @strictNullChecks: false
+// @declaration: true
+// @emitDeclarationOnly: true
+
+// @filename: createApi.ts
+
+type Id<T> = {
+  [K in keyof T]: T[K];
+} & {};
+
+export declare function createApi<Definitions>(_: { endpoints: Definitions }): {
+  [K in keyof Definitions as `use${Capitalize<K & string>}Query`]: () => Id<{
+    status: "uninitialized";
+    originalArgs?: any[];
+  }>;
+};
+
+// @filename: index.ts
+
+import { createApi } from "./createApi";
+
+const slice = createApi({
+  endpoints: {
+    test: {
+      url: `/user`,
+    },
+  },
+});
+
+export const { useTestQuery } = slice;

tests/cases/compiler/declarationEmitOptionalMappedTypePropertyNoStrictNullChecks3.ts

@@ -0,0 +1,30 @@
+// @strictNullChecks: false
+// @declaration: true
+// @emitDeclarationOnly: true
+
+// @filename: createApi.ts
+
+type Id<T> = {
+  [K in keyof T]: T[K];
+} & {};
+
+export declare function createApi<Definitions>(_: { endpoints: Definitions }): {
+  [K in keyof Definitions as `use${Capitalize<K & string>}Query`]: () => Id<{
+    status: "uninitialized";
+    originalArgs?: never;
+  }>;
+};
+
+// @filename: index.ts
+
+import { createApi } from "./createApi";
+
+const slice = createApi({
+  endpoints: {
+    test: {
+      url: `/user`,
+    },
+  },
+});
+
+export const { useTestQuery } = slice;

tests/cases/compiler/declarationEmitOptionalMappedTypePropertyNoStrictNullChecks4.ts

@@ -0,0 +1,10 @@
+// @strictNullChecks: false
+// @declaration: true
+// @emitDeclarationOnly: true
+
+type InputType = { enable_member_receipts?: boolean };
+type AsEmptyObject<T> = { [K in keyof T]?: undefined };
+
+export const test = {
+  ...({} as AsEmptyObject<InputType>),
+};