describe("toBeNegativeInfinity", function() { it("fails for anything that isn't -Infinity", function() { var matcher = jasmineUnderTest.matchers.toBeNegativeInfinity(), result; result = matcher.compare(1); expect(result.pass).toBe(false); result = matcher.compare(Number.NaN); expect(result.pass).toBe(false); result = matcher.compare(null); expect(result.pass).toBe(false); }); it("has a custom message on failure", function() { var matcher = jasmineUnderTest.matchers.toBeNegativeInfinity(), result = matcher.compare(0); expect(result.message()).toEqual("Expected 0 not to be -Infinity.") }); it("succeeds for -Infinity", function() { var matcher = jasmineUnderTest.matchers.toBeNegativeInfinity(), result = matcher.compare(Number.NEGATIVE_INFINITY); expect(result.pass).toBe(true); expect(result.message).toEqual("Expected actual to be -Infinity.") }); });