describe("CallExpression", () => { test("callee is evaluated before arguments", () => { function foo() {} const values = []; [foo][(values.push("callee"), 0)](values.push("args")); expect(values).toEqual(["callee", "args"]); }); test("arguments are evaluated in order", () => { function foo() {} const values = []; foo(values.push("arg1"), values.push("arg2"), values.push("arg3")); expect(values).toEqual(["arg1", "arg2", "arg3"]); }); test("arguments are evaluated before callee is checked for its type", () => { const values = []; expect(() => { "foo"(values.push("args")); }).toThrowWithMessage(TypeError, "foo is not a function"); expect(values).toEqual(["args"]); expect(() => { "foo"(bar); }).toThrowWithMessage(ReferenceError, "'bar' is not defined"); }); }); describe("NewExpression", () => { test("callee is evaluated before arguments", () => { function Foo() {} const values = []; new [Foo][(values.push("callee"), 0)](values.push("args")); expect(values).toEqual(["callee", "args"]); }); test("arguments are evaluated in order", () => { function Foo() {} const values = []; new Foo(values.push("arg1"), values.push("arg2"), values.push("arg3")); expect(values).toEqual(["arg1", "arg2", "arg3"]); }); test("arguments are evaluated before callee is checked for its type", () => { const values = []; expect(() => { new "Foo"(values.push("args")); }).toThrowWithMessage(TypeError, "Foo is not a constructor"); expect(values).toEqual(["args"]); expect(() => { new "Foo"(bar); }).toThrowWithMessage(ReferenceError, "'bar' is not defined"); }); });