import bit from "./bit"

describe("bit", () => {
    test("can be created from a 0", () => {
        expect(bit(0).value).toBe(0)
    })

    test("can be created from a 1", () => {
        expect(bit(1).value).toBe(1)
    })

    test("is equal to other bit when both values are 1", () => {
        expect(bit(1).equals(bit(1))).toBe(true)
    })

    test("is equal to other bit when both values are 0", () => {
        expect(bit(0).equals(bit(0))).toBe(true)
    })

    test("is not equal to other bit when value is 0 and other value is 1", () => {
        expect(bit(0).equals(bit(1))).toBe(false)
    })

    test("is not equal to other bit when value is 1 and other value is 0", () => {
        expect(bit(1).equals(bit(0))).toBe(false)
    })

    describe("addition", () => {
        describe("sum", () => {
            test("is 0 given 0 and 0", () => {
                expect(bit(0).add(bit(0)).ones.value).toBe(0)
            })

            test("is 1 given 1 and 0", () => {
                expect(bit(1).add(bit(0)).ones.value).toBe(1)
            })

            test("is 1 given 0 and 1", () => {
                expect(bit(0).add(bit(1)).ones.value).toBe(1)
            })

            test("is 0 given 1 and 1", () => {
                expect(bit(1).add(bit(1)).ones.value).toBe(0)
            })
        })

        describe("carry", () => {
            test("is 0 given 0 and 0", () => {
                expect(bit(0).add(bit(0)).carry.value).toBe(0)
            })

            test("is 0 given 1 and 0", () => {
                expect(bit(1).add(bit(0)).carry.value).toBe(0)
            })

            test("is 0 given 0 and 1", () => {
                expect(bit(0).add(bit(1)).carry.value).toBe(0)
            })

            test("is 1 given 1 and 1", () => {
                expect(bit(1).add(bit(1)).carry.value).toBe(1)
            })
        })
    })
})