varint_test.go

package sqlite3utils

import (
	"testing"
)

func assertEqInt(t *testing.T, expect, actual int) {
	if expect != actual {
		t.Error("Expected:", expect, "Actual:", actual)
	}
}

func assertEq(t *testing.T, expect, actual byte) {
	assertEqInt(t, int(expect), int(actual))
}

func assertEqAll(t *testing.T, expect byte, actual []byte) {

	for i, a := range actual {
		if expect != a {
			t.Error("Expected", expect, "Actual", a, "at", i, "in", actual)
		}
	}

}

func TestEncodeMax(t *testing.T) {
	t.Run("v=128", func(t *testing.T) {
		bytes := encodeVarint(128)

		if len(bytes) == 2 {
			assertEq(t, 129, bytes[0])
			assertEq(t, 0, bytes[1])
		} else {
			t.Error("invalid size of bytes", bytes)
		}
	})

	/*
		t.Run("v=240", func(t *testing.T) {
			bytes := encodeVarint(240)
			//fmt.Println(bytes)
			assertEq(t, 240, bytes[0])
		})

		testCase := map[uint64]byte{
			2287:                 248,
			67823:                249,
			16777215:             250,
			4294967295:           251,
			1099511627775:        252,
			281474976710655:      253,
			72057594037927935:    254,
			18446744073709551615: 255,
		}

		for k, v := range testCase {
			t.Run("v="+string(k), func(t *testing.T) {
				bytes := encodeVarint(k)
				//fmt.Println(v, bytes)
				assertEq(t, v, bytes[0])
				assertEqAll(t, 255, bytes[1:])
			})
		}
	*/
}

func TestDecodeMax(t *testing.T) {

	testCase := map[uint64][]byte{}
	testCase[128] = []byte{129, 0}
	/*
		testCase[240] = []byte{240}
		testCase[2287] = []byte{248, 255}
		testCase[67823] = []byte{249, 255, 255}
		testCase[16777215] = []byte{250, 255, 255, 255}
		testCase[4294967295] = []byte{251, 255, 255, 255, 255}
		testCase[1099511627775] = []byte{252, 255, 255, 255, 255, 255}
		testCase[281474976710655] = []byte{253, 255, 255, 255, 255, 255, 255}
		testCase[72057594037927935] = []byte{254, 255, 255, 255, 255, 255, 255, 255}
		testCase[18446744073709551615] = []byte{255, 255, 255, 255, 255, 255, 255, 255, 255}
	*/

	for k, v := range testCase {
		//fmt.Println(decodeVarint([]byte{240}))

		n, _ := decodeVarint(v)
		if n != k {
			t.Error("n>", k, n)
		}
	}
}