Verify multi-level and diamond extends interface hierarchies work correctly

tslang/test/tester/CMakeLists.txt

@@ -291,6 +291,7 @@ add_test(NAME test-compile-00-object-annotated-method COMMAND test-runner "${PRO
 add_test(NAME test-compile-00-object-annotated-method-params COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_params.ts")
 add_test(NAME test-compile-00-object-annotated-method-interleaved COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_interleaved.ts")
 add_test(NAME test-compile-00-object-annotated-method-extends-interface COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_extends_interface.ts")
+add_test(NAME test-compile-00-object-annotated-method-extends-interface-multilevel COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_extends_interface_multilevel.ts")
 add_test(NAME test-compile-00-interface-object-array COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_object_array.ts")
 add_test(NAME test-compile-00-interface-generic COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_generic.ts")
 add_test(NAME test-compile-00-interface-new COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_new.ts")
@@ -649,6 +650,7 @@ add_test(NAME test-jit-00-object-annotated-method COMMAND test-runner -jit "${PR
 add_test(NAME test-jit-00-object-annotated-method-params COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_params.ts")
 add_test(NAME test-jit-00-object-annotated-method-interleaved COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_interleaved.ts")
 add_test(NAME test-jit-00-object-annotated-method-extends-interface COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_extends_interface.ts")
+add_test(NAME test-jit-00-object-annotated-method-extends-interface-multilevel COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00object_annotated_method_extends_interface_multilevel.ts")
 add_test(NAME test-jit-00-interface-object-array COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_object_array.ts")
 add_test(NAME test-jit-00-interface-generic COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_generic.ts")
 add_test(NAME test-jit-00-interface-new COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00interface_new.ts")

tslang/test/tester/tests/00object_annotated_method_extends_interface_multilevel.ts

@@ -0,0 +1,84 @@
+// Extends 00object_annotated_method_extends_interface.ts's coverage (single
+// level: Accumulator extends Base) to a 3-level chain (C extends B extends
+// A) and an interface with TWO extends targets (Combined extends Left,
+// Right) - the "known limitation, not verified" gap flagged when that
+// single-level fix landed (PR #266). Both work correctly with the same
+// fix: InterfaceInfo::getVirtualTable's extends recursion and
+// getAllMethods() are themselves recursive/multi-target already, not
+// hardcoded to one level - this test just locks that in.
+
+function main() {
+    interface A {
+        a: number;
+        addA(n: number): void;
+    }
+    interface B extends A {
+        b: number;
+        addB(n: number): void;
+    }
+    interface C extends B {
+        c: number;
+        addC(n: number): void;
+    }
+
+    let raw = {
+        a: 1.0,
+        addA(n: number) { this.a = this.a + n; },
+        b: 2.0,
+        addB(n: number) { this.b = this.b + n; },
+        c: 3.0,
+        addC(n: number) { this.c = this.c + n; },
+    };
+
+    let obj: C = <C>raw;
+
+    obj.addA(10);
+    assert(obj.a == 11);
+    print(obj.a);
+
+    obj.addB(20);
+    assert(obj.b == 22);
+    print(obj.b);
+
+    obj.addC(30);
+    assert(obj.c == 33);
+    print(obj.c);
+
+    interface Left {
+        left: number;
+        addLeft(n: number): void;
+    }
+    interface Right {
+        right: number;
+        addRight(n: number): void;
+    }
+    interface Combined extends Left, Right {
+        combined: number;
+        addCombined(n: number): void;
+    }
+
+    let rawCombined = {
+        left: 1.0,
+        addLeft(n: number) { this.left = this.left + n; },
+        right: 2.0,
+        addRight(n: number) { this.right = this.right + n; },
+        combined: 3.0,
+        addCombined(n: number) { this.combined = this.combined + n; },
+    };
+
+    let combined: Combined = <Combined>rawCombined;
+
+    combined.addLeft(10);
+    assert(combined.left == 11);
+    print(combined.left);
+
+    combined.addRight(20);
+    assert(combined.right == 22);
+    print(combined.right);
+
+    combined.addCombined(30);
+    assert(combined.combined == 33);
+    print(combined.combined);
+
+    print("done.");
+}