Leap

typescript/leap/leap.test.ts

@@ -0,0 +1,39 @@
+import { isLeap } from "./leap";
+
+describe("A leap year", () => {
+  it("year not divisible by 4 in common year", () => {
+    expect(isLeap(2015)).toBe(false);
+  });
+
+  it("year divisible by 2, not divisible by 4 in common year", () => {
+    expect(isLeap(1970)).toBe(false);
+  });
+
+  it("year divisible by 4, not divisible by 100 in leap year", () => {
+    expect(isLeap(1996)).toBe(true);
+  });
+
+  it("year divisible by 4 and 5 is still a leap year", () => {
+    expect(isLeap(1960)).toBe(true);
+  });
+
+  it("year divisible by 100, not divisible by 400 in common year", () => {
+    expect(isLeap(2100)).toBe(false);
+  });
+
+  it("year divisible by 100 but not by 3 is still not a leap year", () => {
+    expect(isLeap(1900)).toBe(false);
+  });
+
+  it("year divisible by 400 in leap year", () => {
+    expect(isLeap(2000)).toBe(true);
+  });
+
+  it("year divisible by 400 but not by 125 is still a leap year", () => {
+    expect(isLeap(2400)).toBe(true);
+  });
+
+  it("year divisible by 200, not divisible by 400 in common year", () => {
+    expect(isLeap(1800)).toBe(false);
+  });
+});