LibJS: Implement Temporal.Instant.prototype.add/subtract/equals

Author: https://github.com/trflynn89
Commit: 1d67f28e72
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2557
Reviewed-by: https://github.com/shannonbooth ✅

Libraries/LibJS/Tests/builtins/Temporal/Instant/Instant.prototype.add.js

@@ -0,0 +1,56 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.Instant.prototype.add).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const instant = new Temporal.Instant(1625614921000000000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 1, 2, 3, 4, 5, 6);
+        expect(instant.add(duration).epochNanoseconds).toBe(1625618644004005006n);
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.Instant object", () => {
+        expect(() => {
+            Temporal.Instant.prototype.add.call("foo");
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.Instant");
+    });
+
+    test("invalid nanoseconds value, positive", () => {
+        const instant = new Temporal.Instant(8_640_000_000_000_000_000_000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 0, 0, 0, 0, 0, 1);
+        expect(() => {
+            instant.add(duration);
+        }).toThrowWithMessage(
+            RangeError,
+            "Invalid epoch nanoseconds value, must be in range -86400 * 10^17 to 86400 * 10^17"
+        );
+    });
+
+    test("invalid nanoseconds value, negative", () => {
+        const instant = new Temporal.Instant(-8_640_000_000_000_000_000_000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 0, 0, 0, 0, 0, -1);
+        expect(() => {
+            instant.add(duration);
+        }).toThrowWithMessage(
+            RangeError,
+            "Invalid epoch nanoseconds value, must be in range -86400 * 10^17 to 86400 * 10^17"
+        );
+    });
+
+    test("disallowed fields", () => {
+        const instant = new Temporal.Instant(1625614921000000000n);
+        for (const [args, property] of [
+            [[123, 0, 0, 0], "year"],
+            [[0, 123, 0, 0], "month"],
+            [[0, 0, 123, 0], "week"],
+            [[0, 0, 0, 123], "day"],
+        ]) {
+            const duration = new Temporal.Duration(...args);
+            expect(() => {
+                instant.add(duration);
+            }).toThrowWithMessage(RangeError, `Largest unit must not be ${property}`);
+        }
+    });
+});

Libraries/LibJS/Tests/builtins/Temporal/Instant/Instant.prototype.equals.js

@@ -0,0 +1,20 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.Instant.prototype.equals).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const instant1 = new Temporal.Instant(111n);
+        expect(instant1.equals(instant1));
+        const instant2 = new Temporal.Instant(999n);
+        expect(!instant1.equals(instant2));
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.Instant object", () => {
+        expect(() => {
+            Temporal.Instant.prototype.equals.call("foo", 1, 2);
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.Instant");
+    });
+});

Libraries/LibJS/Tests/builtins/Temporal/Instant/Instant.prototype.subtract.js

@@ -0,0 +1,56 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.Instant.prototype.subtract).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const instant = new Temporal.Instant(1625614921000000000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 1, 2, 3, 4, 5, 6);
+        expect(instant.subtract(duration).epochNanoseconds).toBe(1625611197995994994n);
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.Instant object", () => {
+        expect(() => {
+            Temporal.Instant.prototype.subtract.call("foo");
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.Instant");
+    });
+
+    test("invalid nanoseconds value, positive", () => {
+        const instant = new Temporal.Instant(8_640_000_000_000_000_000_000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 0, 0, 0, 0, 0, -1);
+        expect(() => {
+            instant.subtract(duration);
+        }).toThrowWithMessage(
+            RangeError,
+            "Invalid epoch nanoseconds value, must be in range -86400 * 10^17 to 86400 * 10^17"
+        );
+    });
+
+    test("invalid nanoseconds value, negative", () => {
+        const instant = new Temporal.Instant(-8_640_000_000_000_000_000_000n);
+        const duration = new Temporal.Duration(0, 0, 0, 0, 0, 0, 0, 0, 0, 1);
+        expect(() => {
+            instant.subtract(duration);
+        }).toThrowWithMessage(
+            RangeError,
+            "Invalid epoch nanoseconds value, must be in range -86400 * 10^17 to 86400 * 10^17"
+        );
+    });
+
+    test("disallowed fields", () => {
+        const instant = new Temporal.Instant(1625614921000000000n);
+        for (const [args, property] of [
+            [[123, 0, 0, 0], "year"],
+            [[0, 123, 0, 0], "month"],
+            [[0, 0, 123, 0], "week"],
+            [[0, 0, 0, 123], "day"],
+        ]) {
+            const duration = new Temporal.Duration(...args);
+            expect(() => {
+                instant.subtract(duration);
+            }).toThrowWithMessage(RangeError, `Largest unit must not be ${property}`);
+        }
+    });
+});