pin down truthiness

danvk · Jan 14, 2024 · a567301 · a567301
1 parent 09cae29
commit a567301
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/interpreter.test.ts b/src/interpreter.test.ts
@@ -43,6 +43,14 @@ describe("interpreter", () => {
 		expect(evaluate(`"hello" + " " + "world"`)).toEqual("hello world");
 	});
 
+	it("should evaluate truthiness", () => {
+		expect(evaluate("!true")).toEqual(false);
+		expect(evaluate("!12")).toEqual(false);
+		expect(evaluate("!!nil")).toEqual(false);
+		expect(evaluate("!!0")).toEqual(true);
+		expect(evaluate(`!!""`)).toEqual(true);
+	});
+
 	it("should report an error on mixed + operands", () => {
 		expect(() => evaluate(`"12" + 13`)).toThrowError(
 			"Operands must be two numbers or two strings.",