Lesson 1 homework

Lesson_1/homework_test.go

@@ -1,18 +1,32 @@
 package main
 
 import (
-	"testing"
+	"unsafe"
 
 	"github.com/stretchr/testify/assert"
+
+	"testing"
 )
 
 // go test -v homework_test.go
 
-func ToLittleEndian(number uint32) uint32 {
-	return 0 // need to implement
+func ToLittleEndian[T uint16 | uint32 | uint64](number T) T {
+	size := int(unsafe.Sizeof(number))
+
+	var result T
+	ptr := unsafe.Pointer(&number)
+	resultPtr := unsafe.Pointer(&result)
+
+	for i := 0; i < size; i++ {
+		srcByte := *(*byte)(unsafe.Pointer(uintptr(ptr) + uintptr(size-i-1)))
+		dstByte := (*byte)(unsafe.Pointer(uintptr(resultPtr) + uintptr(i)))
+		*dstByte = srcByte
+	}
+
+	return result
 }
 
-func TestСonversion(t *testing.T) {
+func TestConversionUint32(t *testing.T) {
 	tests := map[string]struct {
 		number uint32
 		result uint32
@@ -37,6 +51,116 @@ func TestСonversion(t *testing.T) {
 			number: 0x01020304,
 			result: 0x04030201,
 		},
+		"test case #6": {
+			number: 0xAABBCCDD,
+			result: 0xDDCCBBAA,
+		},
+		"test case #7": {
+			number: 0x12345678,
+			result: 0x78563412,
+		},
+		"test case #8": {
+			number: 0x00000001,
+			result: 0x01000000,
+		},
+		"test case #9": {
+			number: 0x01000000,
+			result: 0x00000001,
+		},
+		"test case #10": {
+			number: 0x00010000,
+			result: 0x00000100,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			result := ToLittleEndian(test.number)
+			assert.Equal(t, test.result, result)
+		})
+	}
+}
+
+func TestConversionUint64(t *testing.T) {
+	tests := map[string]struct {
+		number uint64
+		result uint64
+	}{
+		"test case #1": {
+			number: 0x0000000000000000,
+			result: 0x0000000000000000,
+		},
+		"test case #2": {
+			number: 0xFFFFFFFFFFFFFFFF,
+			result: 0xFFFFFFFFFFFFFFFF,
+		},
+		"test case #3": {
+			number: 0x01_23_45_67_89_AB_CD_EF,
+			result: 0xEF_CD_AB_89_67_45_23_01,
+		},
+		"test case #4": {
+			number: 0x0000FFFF0000FFFF,
+			result: 0xFFFF0000FFFF0000,
+		},
+		"test case #5": {
+			number: 0xFFFF0000FFFF0000,
+			result: 0x0000FFFF0000FFFF,
+		},
+		"test case #6": {
+			number: 0xAAAACCCCEEEEFFFF,
+			result: 0xFFFFEEEECCCCAAAA,
+		},
+		"test case #7": {
+			number: 0x000000000000000F,
+			result: 0x0F00000000000000,
+		},
+		"test case #8": {
+			number: 0x0F00000000000000,
+			result: 0x000000000000000F,
+		},
+		"test case #9": {
+			number: 0x00_00_00_0F_00_00_00_00,
+			result: 0x00_00_00_00_0F_00_00_00,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			result := ToLittleEndian(test.number)
+			assert.Equal(t, test.result, result)
+		})
+	}
+}
+
+func TestConversionUint16(t *testing.T) {
+	tests := map[string]struct {
+		number uint16
+		result uint16
+	}{
+		"test case #1": {
+			number: 0x0000,
+			result: 0x0000,
+		},
+		"test case #2": {
+			number: 0xFFFF,
+			result: 0xFFFF,
+		},
+		"test case #3": {
+			number: 0x0FF0,
+			result: 0xF00F,
+		},
+		"test case #5": {
+			number: 0x00FF,
+			result: 0xFF00,
+		},
+		"test case #6": {
+			number: 0x000F,
+			result: 0x0F00,
+		},
+		"test case #7": {
+			number: 0x1234,
+			result: 0x3412,
+		},
 	}
 
 	for name, test := range tests {