LibJS: Add SuppressedError{, Prototype, Constructor}

Userland/Libraries/LibJS/Tests/builtins/SuppressedError/SuppressedError.js

@@ -0,0 +1,57 @@
+describe("normal behavior", () => {
+    test("length is 2", () => {
+        expect(SuppressedError).toHaveLength(3);
+    });
+
+    test("name is SuppressedError", () => {
+        expect(SuppressedError.name).toBe("SuppressedError");
+    });
+
+    test("Prototype of the SuppressedError constructor is the Error constructor", () => {
+        expect(Object.getPrototypeOf(SuppressedError)).toBe(Error);
+    });
+
+    test("Prototype of SuppressedError.prototype is Error.prototype", () => {
+        expect(Object.getPrototypeOf(SuppressedError.prototype)).toBe(Error.prototype);
+    });
+
+    test("construction", () => {
+        expect(SuppressedError()).toBeInstanceOf(SuppressedError);
+        expect(SuppressedError(1)).toBeInstanceOf(SuppressedError);
+        expect(SuppressedError(1, 1)).toBeInstanceOf(SuppressedError);
+        expect(new SuppressedError()).toBeInstanceOf(SuppressedError);
+        expect(new SuppressedError(1)).toBeInstanceOf(SuppressedError);
+        expect(new SuppressedError(1, 1)).toBeInstanceOf(SuppressedError);
+        expect(Object.hasOwn(new SuppressedError(1, 1), "message")).toBeFalse();
+        expect(new SuppressedError().toString()).toBe("SuppressedError");
+        expect(new SuppressedError(1).toString()).toBe("SuppressedError");
+        expect(new SuppressedError(1, 1).toString()).toBe("SuppressedError");
+        expect(new SuppressedError(undefined, undefined, "Foo").toString()).toBe(
+            "SuppressedError: Foo"
+        );
+        expect(new SuppressedError(1, 1, "Foo").toString()).toBe("SuppressedError: Foo");
+        expect(Object.hasOwn(new SuppressedError(), "error")).toBeTrue();
+        expect(Object.hasOwn(new SuppressedError(), "suppressed")).toBeTrue();
+        const obj = {};
+        expect(new SuppressedError(obj).error).toBe(obj);
+        expect(new SuppressedError(null, obj).suppressed).toBe(obj);
+    });
+
+    test("converts message to string", () => {
+        expect(new SuppressedError(undefined, undefined, 1)).toHaveProperty("message", "1");
+        expect(new SuppressedError(undefined, undefined, {})).toHaveProperty(
+            "message",
+            "[object Object]"
+        );
+    });
+
+    test("supports options object with cause", () => {
+        const cause = new Error();
+        const error = new SuppressedError(1, 2, "test", { cause });
+        expect(error.hasOwnProperty("cause")).toBeTrue();
+        expect(error.cause).toBe(cause);
+
+        const errorWithoutCase = new SuppressedError(1, 2, "test");
+        expect(errorWithoutCase.hasOwnProperty("cause")).toBeFalse();
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/SuppressedError/SuppressedError.prototype.message.js

@@ -0,0 +1,21 @@
+describe("normal behavior", () => {
+    test("initial message value is empty string", () => {
+        expect(SuppressedError.prototype.message).toBe("");
+    });
+
+    test("Error gets message via prototype by default", () => {
+        const error = new SuppressedError();
+        expect(error.hasOwnProperty("message")).toBeFalse();
+        expect(error.message).toBe("");
+        SuppressedError.prototype.message = "Well hello friends";
+        expect(error.message).toBe("Well hello friends");
+    });
+
+    test("Error gets message via object if given to constructor", () => {
+        const error = new SuppressedError(undefined, undefined, "Custom error message");
+        expect(error.hasOwnProperty("message")).toBeTrue();
+        expect(error.message).toBe("Custom error message");
+        SuppressedError.prototype.message = "Well hello friends";
+        expect(error.message).toBe("Custom error message");
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/SuppressedError/SuppressedError.prototype.name.js

@@ -0,0 +1,13 @@
+describe("normal behavior", () => {
+    test("initial name value is type name", () => {
+        expect(SuppressedError.prototype.name).toBe("SuppressedError");
+    });
+
+    test("Error gets name via prototype", () => {
+        const error = new SuppressedError([]);
+        expect(error.hasOwnProperty("name")).toBeFalse();
+        expect(error.name).toBe("SuppressedError");
+        SuppressedError.prototype.name = "Foo";
+        expect(error.name).toBe("Foo");
+    });
+});