feat: dateutils, maputils, sliceutils.

dateutils/dateutils.go

@@ -0,0 +1,32 @@
+package dateutils
+
+import "time"
+
+// Floor - takes a datetime and return a datetime from the same day at 00:00:00 (UTC).
+func Floor(t time.Time) time.Time {
+	return t.UTC().Truncate(time.Hour * 24)
+}
+
+// Ceil - takes a datetime and return a datetime from the same day at 23:59:59 (UTC).
+func Ceil(t time.Time) time.Time {
+	// add 24 hours so that we are dealing with tomorrow's datetime
+	// Floor
+	// Substract one second and we have today at 23:59:59
+	return Floor(t.Add(time.Hour * 24)).Add(time.Second * -1)
+}
+
+func BeforeOrEqual(milestone time.Time, date time.Time) bool {
+	return date.UTC().Before(milestone) || date.UTC().Equal(milestone)
+}
+
+func AfterOrEqual(milestone time.Time, date time.Time) bool {
+	return date.UTC().After(milestone) || date.UTC().Equal(milestone)
+}
+
+// Overlap - returns true if two date intervals overlap.
+func Overlap(start1 time.Time, end1 time.Time, start2 time.Time, end2 time.Time) bool {
+	return (AfterOrEqual(start2, start1) && BeforeOrEqual(end2, start1)) ||
+		(AfterOrEqual(start2, end1) && BeforeOrEqual(end2, end1)) ||
+		(AfterOrEqual(start1, start2) && BeforeOrEqual(end1, start2)) ||
+		(AfterOrEqual(start1, end2) && BeforeOrEqual(end1, end2))
+}

dateutils/dateutils_test.go

@@ -0,0 +1,66 @@
+package dateutils_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tx7do/go-utils/dateutils"
+)
+
+func TestFloor(t *testing.T) {
+	now := time.Now()
+	assert.Equal(t, "00:00:00", dateutils.Floor(now).Format("15:04:05"))
+}
+
+func TestCeil(t *testing.T) {
+	now := time.Now()
+	assert.Equal(t, "23:59:59", dateutils.Ceil(now).Format("15:04:05"))
+}
+
+func TestBeforeOrEqual(t *testing.T) {
+	milestone, _ := time.Parse("2006-01-02", "2023-01-01")
+
+	dBefore, _ := time.Parse("2006-01-02", "2022-12-31")
+	dEqual, _ := time.Parse("2006-01-02", "2023-01-01")
+	dAfter, _ := time.Parse("2006-01-02", "2023-01-31")
+
+	assert.Equal(t, true, dateutils.BeforeOrEqual(milestone, dBefore))
+	assert.Equal(t, true, dateutils.BeforeOrEqual(milestone, dEqual))
+	assert.Equal(t, false, dateutils.BeforeOrEqual(milestone, dAfter))
+}
+
+func TestAfterOrEqual(t *testing.T) {
+	milestone, _ := time.Parse("2006-01-02", "2023-01-01")
+
+	dBefore, _ := time.Parse("2006-01-02", "2022-12-31")
+	dEqual, _ := time.Parse("2006-01-02", "2023-01-01")
+	dAfter, _ := time.Parse("2006-01-02", "2023-01-31")
+
+	assert.Equal(t, false, dateutils.AfterOrEqual(milestone, dBefore))
+	assert.Equal(t, true, dateutils.AfterOrEqual(milestone, dEqual))
+	assert.Equal(t, true, dateutils.AfterOrEqual(milestone, dAfter))
+}
+
+func TestOverlap(t *testing.T) {
+	s1, _ := time.Parse("2006-01-02", "2022-12-28")
+	e1, _ := time.Parse("2006-01-02", "2022-12-31")
+
+	s2, _ := time.Parse("2006-01-02", "2022-12-30")
+	e2, _ := time.Parse("2006-01-02", "2023-01-01")
+
+	s3, _ := time.Parse("2006-01-02", "2023-01-02")
+	e3, _ := time.Parse("2006-01-02", "2023-01-04")
+
+	assert.Equal(t, true, dateutils.Overlap(s1, e1, s2, e2))
+	assert.Equal(t, false, dateutils.Overlap(s1, e1, s3, e3))
+
+	s4, _ := time.Parse("2006-01-02", "2023-07-13")
+	e4, _ := time.Parse("2006-01-02", "2023-07-14")
+
+	s5, _ := time.Parse("2006-01-02", "2023-07-10")
+	e5, _ := time.Parse("2006-01-02", "2023-07-17")
+
+	assert.Equal(t, true, dateutils.Overlap(s4, e4, s5, e5))
+	assert.Equal(t, true, dateutils.Overlap(s5, e5, s4, e4))
+}

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/sony/sonyflake v1.2.0
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/crypto v0.14.0
+	golang.org/x/exp v0.0.0-20231006140011-7918f672742d
 )
 
 require (

go.sum

@@ -26,6 +26,8 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 golang.org/x/crypto v0.14.0 h1:wBqGXzWJW6m1XrIKlAH0Hs1JJ7+9KBwnIO8v66Q9cHc=
 golang.org/x/crypto v0.14.0/go.mod h1:MVFd36DqK4CsrnJYDkBA3VC4m2GkXAM0PvzMCn4JQf4=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

maputils/maputils.go

@@ -0,0 +1,94 @@
+// This package includes utility functions for handling and manipulating maputils.
+// It draws inspiration from JavaScript and Python and uses Go generics as a basis.
+
+package maputils
+
+// Keys - takes a map with keys K and values V, returns a slice of type K of the map's keys.
+// Note: Go maps do not preserve insertion order.
+func Keys[K comparable, V any](mapInstance map[K]V) []K {
+	keys := make([]K, len(mapInstance))
+
+	i := 0
+	for k := range mapInstance {
+		keys[i] = k
+		i++
+	}
+
+	return keys
+}
+
+// Values - takes a map with keys K and values V, returns a slice of type V of the map's values.
+// Note: Go maps do not preserve insertion order.
+func Values[K comparable, V any](mapInstance map[K]V) []V {
+	values := make([]V, len(mapInstance))
+
+	i := 0
+	for _, v := range mapInstance {
+		values[i] = v
+		i++
+	}
+
+	return values
+}
+
+// Merge - takes an arbitrary number of map instances with keys K and values V and merges them into a single map.
+// Note: merge works from left to right. If a key already exists in a previous map, its value is over-written.
+func Merge[K comparable, V any](mapInstances ...map[K]V) map[K]V {
+	var mergedMapSize int
+
+	for _, mapInstance := range mapInstances {
+		mergedMapSize += len(mapInstance)
+	}
+
+	mergedMap := make(map[K]V, mergedMapSize)
+
+	for _, mapInstance := range mapInstances {
+		for k, v := range mapInstance {
+			mergedMap[k] = v
+		}
+	}
+
+	return mergedMap
+}
+
+// ForEach - given a map with keys K and values V, executes the passed in function for each key-value pair.
+func ForEach[K comparable, V any](mapInstance map[K]V, function func(key K, value V)) {
+	for key, value := range mapInstance {
+		function(key, value)
+	}
+}
+
+// Drop - takes a map with keys K and values V, and a slice of keys K, dropping all the key-value pairs that match the keys in the slice.
+// Note: this function will modify the passed in map. To get a different object, use the Copy function to pass a copy to this function.
+func Drop[K comparable, V any](mapInstance map[K]V, keys []K) map[K]V {
+	for _, key := range keys {
+		delete(mapInstance, key)
+	}
+
+	return mapInstance
+}
+
+// Copy - takes a map with keys K and values V and returns a copy of the map.
+func Copy[K comparable, V any](mapInstance map[K]V) map[K]V {
+	mapCopy := make(map[K]V, len(mapInstance))
+
+	for key, value := range mapInstance {
+		mapCopy[key] = value
+	}
+
+	return mapCopy
+}
+
+// Filter - takes a map with keys K and values V, and executes the passed in function for each key-value pair.
+// If the filter function returns true, the key-value pair will be included in the output, otherwise it is filtered out.
+func Filter[K comparable, V any](mapInstance map[K]V, function func(key K, value V) bool) map[K]V {
+	mapCopy := make(map[K]V, len(mapInstance))
+
+	for key, value := range mapInstance {
+		if function(key, value) {
+			mapCopy[key] = value
+		}
+	}
+
+	return mapCopy
+}

maputils/maputils_test.go

@@ -0,0 +1,139 @@
+package maputils_test
+
+import (
+	"sort"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tx7do/go-utils/maputils"
+)
+
+func TestKeys(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+	keys := maputils.Keys(daysMap)
+	days := []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
+	sort.Strings(days)
+	sort.Strings(keys)
+	assert.Equal(t, days, keys)
+}
+
+func TestValues(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+	values := maputils.Values(daysMap)
+	sort.Ints(values)
+	assert.Equal(t, []int{1, 2, 3, 4, 5, 6, 7}, values)
+}
+
+func TestMerge(t *testing.T) {
+	first := map[string]string{
+		"George": "Harrison",
+		"Betty":  "Davis",
+	}
+	second := map[string]string{
+		"Ronald": "Reagen",
+		"Betty":  "Stewart",
+	}
+
+	assert.Equal(t,
+		map[string]string{
+			"George": "Harrison",
+			"Betty":  "Stewart",
+			"Ronald": "Reagen",
+		}, maputils.Merge(first, second))
+}
+
+func TestForEach(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+
+	sum := 0
+
+	maputils.ForEach(daysMap, func(_ string, day int) {
+		sum += day
+	})
+
+	assert.Equal(t, 28, sum)
+}
+
+func TestDrop(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+
+	expectedResult := map[string]int{
+		"Sunday": 1,
+		"Friday": 6,
+	}
+	assert.Equal(t, expectedResult, maputils.Drop(daysMap, []string{"Monday", "Tuesday", "Wednesday", "Thursday", "Saturday"}))
+	// ensure we do not modify the original value
+	assert.Equal(t, expectedResult, daysMap)
+}
+
+func TestCopy(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+	daysCopy := maputils.Copy(daysMap)
+	assert.Equal(t, daysMap, daysCopy)
+	delete(daysCopy, "Sunday")
+	assert.NotEqual(t, daysMap, daysCopy)
+}
+
+func TestFilter(t *testing.T) {
+	var daysMap = map[string]int{
+		"Sunday":    1,
+		"Monday":    2,
+		"Tuesday":   3,
+		"Wednesday": 4,
+		"Thursday":  5,
+		"Friday":    6,
+		"Saturday":  7,
+	}
+
+	var expectedResult = map[string]int{
+		"Monday":    2,
+		"Wednesday": 4,
+		"Friday":    6,
+	}
+
+	filteredDays := maputils.Filter(daysMap, func(_ string, value int) bool {
+		return value%2 == 0
+	})
+
+	assert.Equal(t, expectedResult, filteredDays)
+}

sliceutils/sliceutils.go

@@ -0,0 +1,375 @@
+// This package includes utility functions for handling and manipulating a slice.
+// It draws inspiration from JavaScript and Python and uses Go generics as a basis.
+
+package sliceutils
+
+import (
+	"golang.org/x/exp/constraints"
+)
+
+// Filter - given a slice of type T, executes the given predicate function on each element in the slice.
+// The predicate is passed the current element, the current index and the slice itself as function arguments.
+// If the predicate returns true, the value is included in the result, otherwise it is filtered out.
+func Filter[T any](slice []T, predicate func(value T, index int, slice []T) bool) (filtered []T) {
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); ok {
+			filtered = append(filtered, el)
+		}
+	}
+	return filtered
+}
+
+// ForEach - given a slice of type T, executes the passed in function for each element in the slice.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func ForEach[T any](slice []T, function func(value T, index int, slice []T)) {
+	for i, el := range slice {
+		function(el, i, slice)
+	}
+}
+
+// Map - given a slice of type T, executes the passed in mapper function for each element in the slice, returning a slice of type R.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func Map[T any, R any](slice []T, mapper func(value T, index int, slice []T) R) (mapped []R) {
+	if len(slice) > 0 {
+		mapped = make([]R, len(slice))
+		for i, el := range slice {
+			mapped[i] = mapper(el, i, slice)
+		}
+	}
+	return mapped
+}
+
+// Reduce - given a slice of type T, executes the passed in reducer function for each element in the slice, returning a result of type R.
+// The function is passed the accumulator, current element, current index and the slice itself as function arguments.
+// The third argument to reduce is the initial value of type R to use.
+func Reduce[T any, R any](slice []T, reducer func(acc R, value T, index int, slice []T) R, initial R) R {
+	acc := initial
+	for i, el := range slice {
+		acc = reducer(acc, el, i, slice)
+	}
+	return acc
+}
+
+// Find - given a slice of type T, executes the passed in predicate function for each element in the slice.
+// If the predicate returns true - a pointer to the element is returned. If no element is found, nil is returned.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func Find[T any](slice []T, predicate func(value T, index int, slice []T) bool) *T {
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); ok {
+			return &el
+		}
+	}
+	return nil
+}
+
+// FindIndex - given a slice of type T, executes the passed in predicate function for each element in the slice.
+// If the predicate returns true - the index of the element is returned. If no element is found, -1 is returned.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func FindIndex[T any](slice []T, predicate func(value T, index int, slice []T) bool) int {
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); ok {
+			return i
+		}
+	}
+	return -1
+}
+
+// FindIndexOf - given a slice of type T and a value of type T, return ths first index of an element equal to value.
+// If no element is found, -1 is returned.
+func FindIndexOf[T comparable](slice []T, value T) int {
+	for i, el := range slice {
+		if el == value {
+			return i
+		}
+	}
+	return -1
+}
+
+// FindLastIndex - given a slice of type T, executes the passed in predicate function for each element in the slice starting from its end.
+// If no element is found, -1 is returned. The function is passed the current element, the current index and the slice itself as function arguments.
+func FindLastIndex[T any](slice []T, predicate func(value T, index int, slice []T) bool) int {
+	for i := len(slice) - 1; i > 0; i-- {
+		el := slice[i]
+		if ok := predicate(el, i, slice); ok {
+			return i
+		}
+	}
+	return -1
+}
+
+// FindLastIndexOf - given a slice of type T and a value of type T, returning the last index matching the given value.
+// If no element is found, -1 is returned.
+func FindLastIndexOf[T comparable](slice []T, value T) int {
+	for i := len(slice) - 1; i > 0; i-- {
+		el := slice[i]
+		if el == value {
+			return i
+		}
+	}
+	return -1
+}
+
+// FindIndexes - given a slice of type T, executes the passed in predicate function for each element in the slice.
+// Returns a slice containing all indexes of elements for which the predicate returned true. If no element are found, returns a nil int slice.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func FindIndexes[T any](slice []T, predicate func(value T, index int, slice []T) bool) []int {
+	var indexes []int
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); ok {
+			indexes = append(indexes, i)
+		}
+	}
+	return indexes
+}
+
+// FindIndexesOf - given a slice of type T and a value of type T, returns a slice containing all indexes match the given value.
+// If no element are found, returns a nil int slice.
+func FindIndexesOf[T comparable](slice []T, value T) []int {
+	var indexes []int
+	for i, el := range slice {
+		if el == value {
+			indexes = append(indexes, i)
+		}
+	}
+	return indexes
+}
+
+// Includes - given a slice of type T and a value of type T, determines whether the value is contained by the slice.
+// Note: T is constrained to comparable types only and comparison is determined using the equality operator.
+func Includes[T comparable](slice []T, value T) bool {
+	for _, el := range slice {
+		if el == value {
+			return true
+		}
+	}
+	return false
+}
+
+// Some - given a slice of type T, executes the given predicate for each element of the slice.
+// If the predicate returns true for any element, it returns true, otherwise it returns false.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func Some[T any](slice []T, predicate func(value T, index int, slice []T) bool) bool {
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); ok {
+			return true
+		}
+	}
+	return false
+}
+
+// Every - given a slice of type T, executes the given predicate for each element of the slice.
+// If the predicate returns true for all elements, it returns true, otherwise it returns false.
+// The function is passed the current element, the current index and the slice itself as function arguments.
+func Every[T any](slice []T, predicate func(value T, index int, slice []T) bool) bool {
+	for i, el := range slice {
+		if ok := predicate(el, i, slice); !ok {
+			return false
+		}
+	}
+	return true
+}
+
+// Merge - receives slices of type T and merges them into a single slice of type T.
+// Note: The elements are merged in their order in a slice,
+// i.e. first the elements of the first slice, then that of the second and so forth.
+func Merge[T any](slices ...[]T) (mergedSlice []T) {
+	if len(slices) > 0 {
+		mergedSliceCap := 0
+
+		for _, slice := range slices {
+			mergedSliceCap += len(slice)
+		}
+
+		if mergedSliceCap > 0 {
+			mergedSlice = make([]T, 0, mergedSliceCap)
+
+			for _, slice := range slices {
+				mergedSlice = append(mergedSlice, slice...)
+			}
+		}
+	}
+	return mergedSlice
+}
+
+// Sum - receives a slice of type T and returns a value T that is the sum of the numbers.
+// Note: T is constrained to be a number type.
+func Sum[T constraints.Complex | constraints.Integer | constraints.Float](slice []T) (result T) {
+	for _, el := range slice {
+		result += el
+	}
+	return result
+}
+
+// Remove - receives a slice of type T and an index, removing the element at the given index.
+// Note: this function does not modify the input slice.
+func Remove[T any](slice []T, i int) []T {
+	if len(slice) == 0 || i > len(slice)-1 {
+		return slice
+	}
+	copied := Copy(slice)
+	if i == 0 {
+		return copied[1:]
+	}
+	if i != len(copied)-1 {
+		return append(copied[:i], copied[i+1:]...)
+	}
+	return copied[:i]
+}
+
+// Insert - receives a slice of type T, an index and a value.
+// The value is inserted at the given index. If there is an existing value at this index, it is shifted to the next index.
+// Note: this function does not modify the input slice.
+func Insert[T any](slice []T, i int, value T) []T {
+	if len(slice) == i {
+		return append(slice, value)
+	}
+	slice = append(slice[:i+1], slice[i:]...)
+	slice[i] = value
+	return slice
+}
+
+// Copy - receives a slice of type T and copies it.
+func Copy[T any](slice []T) []T {
+	duplicate := make([]T, len(slice), cap(slice))
+	copy(duplicate, slice)
+	return duplicate
+}
+
+// Intersection - takes a variadic number of slices of type T and returns a slice of type T containing any values that exist in all the slices.
+// For example, given []int{1, 2, 3}, []int{1, 7, 3}, the intersection would be []int{1, 3}.
+func Intersection[T comparable](slices ...[]T) []T {
+	possibleIntersections := map[T]int{}
+	for i, slice := range slices {
+		for _, el := range slice {
+			if i == 0 {
+				possibleIntersections[el] = 0
+			} else if _, elementExists := possibleIntersections[el]; elementExists {
+				possibleIntersections[el] = i
+			}
+		}
+	}
+
+	intersected := make([]T, 0)
+	for _, el := range slices[0] {
+		if lastVisitorIndex, exists := possibleIntersections[el]; exists && lastVisitorIndex == len(slices)-1 {
+			intersected = append(intersected, el)
+			delete(possibleIntersections, el)
+		}
+	}
+
+	return intersected
+}
+
+// Difference - takes a variadic number of slices of type T and returns a slice of type T containing the elements that are different between the slices.
+// For example, given []int{1, 2, 3}, []int{2, 3, 4}, []{3, 4, 5}, the difference would be []int{1, 5}.
+func Difference[T comparable](slices ...[]T) []T {
+	possibleDifferences := map[T]int{}
+	nonDifferentElements := map[T]int{}
+
+	for i, slice := range slices {
+		for _, el := range slice {
+			if lastVisitorIndex, elementExists := possibleDifferences[el]; elementExists && lastVisitorIndex != i {
+				nonDifferentElements[el] = i
+			} else if !elementExists {
+				possibleDifferences[el] = i
+			}
+		}
+	}
+
+	differentElements := make([]T, 0)
+
+	for _, slice := range slices {
+		for _, el := range slice {
+			if _, exists := nonDifferentElements[el]; !exists {
+				differentElements = append(differentElements, el)
+			}
+		}
+	}
+
+	return differentElements
+}
+
+// Union - takes a variadic number of slices of type T and returns a slice of type T containing the unique elements in the different slices
+// For example, given []int{1, 2, 3}, []int{2, 3, 4}, []int{3, 4, 5}, the union would be []int{1, 2, 3, 4, 5}.
+func Union[T comparable](slices ...[]T) []T {
+	return Unique(Merge(slices...))
+}
+
+// Reverse - takes a slice of type T and returns a slice of type T with a reverse order of elements.
+func Reverse[T any](slice []T) []T {
+	result := make([]T, len(slice))
+
+	itemCount := len(slice)
+	middle := itemCount / 2
+	result[middle] = slice[middle]
+
+	for i := 0; i < middle; i++ {
+		mirrorIdx := itemCount - i - 1
+		result[i], result[mirrorIdx] = slice[mirrorIdx], slice[i]
+	}
+	return result
+}
+
+// Unique - receives a slice of type T and returns a slice of type T containing all unique elements.
+func Unique[T comparable](slice []T) []T {
+	unique := make([]T, 0)
+	visited := map[T]bool{}
+
+	for _, value := range slice {
+		if exists := visited[value]; !exists {
+			unique = append(unique, value)
+			visited[value] = true
+		}
+	}
+	return unique
+}
+
+// Chunk - receives a slice of type T and size N and returns a slice of slices T of size N.
+func Chunk[T any](input []T, size int) [][]T {
+	var chunks [][]T
+
+	for i := 0; i < len(input); i += size {
+		end := i + size
+		if end > len(input) {
+			end = len(input)
+		}
+		chunks = append(chunks, input[i:end])
+	}
+	return chunks
+}
+
+// Pluck - receives a slice of type I and a getter func to a field
+// and returns a slice containing the requested field's value from each item in the slice.
+func Pluck[I any, O any](input []I, getter func(I) *O) []O {
+	var output []O
+
+	for _, item := range input {
+		field := getter(item)
+
+		if field != nil {
+			output = append(output, *field)
+		}
+	}
+
+	return output
+}
+
+// Flatten - receives a slice of slices of type I and flattens it to a slice of type I.
+func Flatten[I any](input [][]I) (output []I) {
+	if len(input) > 0 {
+		var outputSize int
+
+		for _, item := range input {
+			outputSize += len(item)
+		}
+
+		if outputSize > 0 {
+			output = make([]I, 0, outputSize)
+
+			for _, item := range input {
+				output = append(output, item...)
+			}
+		}
+	}
+	return output
+}

sliceutils/sliceutils_test.go

@@ -0,0 +1,301 @@
+package sliceutils_test
+
+import (
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tx7do/go-utils/sliceutils"
+)
+
+type MyInt int
+
+type Pluckable struct {
+	Code  string
+	Value string
+}
+
+var numerals = []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+var numeralsWithUserDefinedType = []MyInt{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+var days = []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
+var lastNames = []string{"Jacobs", "Vin", "Jacobs", "Smith"}
+
+func TestFilter(t *testing.T) {
+	expectedResult := []int{0, 2, 4, 6, 8}
+	actualResult := sliceutils.Filter(numerals, func(value int, _ int, _ []int) bool {
+		return value%2 == 0
+	})
+	assert.Equal(t, expectedResult, actualResult)
+}
+
+func TestForEach(t *testing.T) {
+	result := 0
+	sliceutils.ForEach(numerals, func(value int, _ int, _ []int) {
+		result += value
+	})
+	assert.Equal(t, 45, result)
+}
+
+func TestMap(t *testing.T) {
+	expectedResult := []string{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}
+	actualResult := sliceutils.Map(numerals, func(value int, _ int, _ []int) string {
+		return strconv.Itoa(value)
+	})
+	assert.Equal(t, expectedResult, actualResult)
+
+	assert.Nil(t, sliceutils.Map([]int{}, func(_ int, _ int, _ []int) string {
+		return ""
+	}))
+
+	assert.Nil(t, sliceutils.Map([]int(nil), func(_ int, _ int, _ []int) string {
+		return ""
+	}))
+}
+
+func TestReduce(t *testing.T) {
+	expectedResult := map[string]string{"result": "0123456789"}
+	actualResult := sliceutils.Reduce(
+		numerals,
+		func(acc map[string]string, cur int, _ int, _ []int) map[string]string {
+			acc["result"] += strconv.Itoa(cur)
+			return acc
+		},
+		map[string]string{"result": ""},
+	)
+	assert.Equal(t, expectedResult, actualResult)
+}
+
+func TestFind(t *testing.T) {
+	expectedResult := "Wednesday"
+	actualResult := sliceutils.Find(days, func(value string, index int, slice []string) bool {
+		return strings.Contains(value, "Wed")
+	})
+	assert.Equal(t, expectedResult, *actualResult)
+	assert.Nil(t, sliceutils.Find(days, func(value string, index int, slice []string) bool {
+		return strings.Contains(value, "Rishon")
+	}))
+}
+
+func TestFindIndex(t *testing.T) {
+	expectedResult := 3
+	actualResult := sliceutils.FindIndex(days, func(value string, index int, slice []string) bool {
+		return strings.Contains(value, "Wed")
+	})
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Equal(t, -1, sliceutils.FindIndex(days, func(value string, index int, slice []string) bool {
+		return strings.Contains(value, "Rishon")
+	}))
+}
+
+func TestFindIndexOf(t *testing.T) {
+	expectedResult := 3
+	actualResult := sliceutils.FindIndexOf(days, "Wednesday")
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Equal(t, -1, sliceutils.FindIndexOf(days, "Rishon"))
+}
+
+func TestFindLastIndex(t *testing.T) {
+	expectedResult := 2
+	actualResult := sliceutils.FindLastIndex(lastNames, func(value string, index int, slice []string) bool {
+		return value == "Jacobs"
+	})
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Equal(t, -1, sliceutils.FindLastIndex(lastNames, func(value string, index int, slice []string) bool {
+		return value == "Hamudi"
+	}))
+}
+
+func TestFindLastIndexOf(t *testing.T) {
+	expectedResult := 2
+	actualResult := sliceutils.FindLastIndexOf(lastNames, "Jacobs")
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Equal(t, -1, sliceutils.FindLastIndexOf(lastNames, "Hamudi"))
+}
+
+func TestFindIndexes(t *testing.T) {
+	expectedResult := []int{0, 2}
+	actualResult := sliceutils.FindIndexes(lastNames, func(value string, index int, slice []string) bool {
+		return value == "Jacobs"
+	})
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Nil(t, sliceutils.FindIndexes(lastNames, func(value string, index int, slice []string) bool {
+		return value == "Hamudi"
+	}))
+}
+
+func TestFindIndexesOf(t *testing.T) {
+	expectedResult := []int{0, 2}
+	actualResult := sliceutils.FindIndexesOf(lastNames, "Jacobs")
+	assert.Equal(t, expectedResult, actualResult)
+	assert.Nil(t, sliceutils.FindIndexesOf(lastNames, "Hamudi"))
+}
+
+func TestIncludes(t *testing.T) {
+	assert.True(t, sliceutils.Includes(numerals, 1))
+	assert.False(t, sliceutils.Includes(numerals, 11))
+}
+
+func TestAny(t *testing.T) {
+	assert.True(t, sliceutils.Some(numerals, func(value int, _ int, _ []int) bool {
+		return value%5 == 0
+	}))
+	assert.False(t, sliceutils.Some(numerals, func(value int, _ int, _ []int) bool {
+		return value == 11
+	}))
+}
+
+func TestAll(t *testing.T) {
+	assert.True(t, sliceutils.Every([]int{1, 1, 1}, func(value int, _ int, _ []int) bool {
+		return value == 1
+	}))
+	assert.False(t, sliceutils.Every([]int{1, 1, 1, 2}, func(value int, _ int, _ []int) bool {
+		return value == 1
+	}))
+}
+
+func TestMerge(t *testing.T) {
+	result := sliceutils.Merge(numerals[:5], numerals[5:])
+	assert.Equal(t, numerals, result)
+
+	assert.Nil(t, sliceutils.Merge([]int(nil), []int(nil)))
+	assert.Nil(t, sliceutils.Merge([]int{}, []int{}))
+}
+
+func TestSum(t *testing.T) {
+	result := sliceutils.Sum(numerals)
+	assert.Equal(t, 45, result)
+}
+
+func TestSum2(t *testing.T) {
+	result := sliceutils.Sum(numeralsWithUserDefinedType)
+	assert.Equal(t, MyInt(45), result)
+}
+
+func TestRemove(t *testing.T) {
+	testSlice := []int{1, 2, 3}
+	result := sliceutils.Remove(testSlice, 1)
+	assert.Equal(t, []int{1, 3}, result)
+	assert.Equal(t, []int{1, 2, 3}, testSlice)
+	result = sliceutils.Remove(result, 1)
+	assert.Equal(t, []int{1}, result)
+	result = sliceutils.Remove(result, 3)
+	assert.Equal(t, []int{1}, result)
+	result = sliceutils.Remove(result, 0)
+	assert.Equal(t, []int{}, result)
+	result = sliceutils.Remove(result, 1)
+	assert.Equal(t, []int{}, result)
+}
+
+func TestCopy(t *testing.T) {
+	testSlice := []int{1, 2, 3}
+	copiedSlice := sliceutils.Copy(testSlice)
+	copiedSlice[0] = 2
+	assert.NotEqual(t, testSlice, copiedSlice)
+}
+
+func TestInsert(t *testing.T) {
+	testSlice := []int{1, 2}
+	result := sliceutils.Insert(testSlice, 0, 3)
+	assert.Equal(t, []int{3, 1, 2}, result)
+	assert.NotEqual(t, testSlice, result)
+	assert.Equal(t, []int{1, 3, 2}, sliceutils.Insert(testSlice, 1, 3))
+	assert.Equal(t, []int{1, 2, 3}, sliceutils.Insert(testSlice, 2, 3))
+}
+
+func TestIntersection(t *testing.T) {
+	expectedResult := []int{3, 4, 5}
+
+	first := []int{1, 2, 3, 4, 5}
+	second := []int{2, 3, 4, 5, 6}
+	third := []int{3, 4, 5, 6, 7}
+
+	assert.Equal(t, expectedResult, sliceutils.Intersection(first, second, third))
+}
+
+func TestDifference(t *testing.T) {
+	expectedResult := []int{1, 7}
+
+	first := []int{1, 2, 3, 4, 5}
+	second := []int{2, 3, 4, 5, 6}
+	third := []int{3, 4, 5, 6, 7}
+
+	assert.Equal(t, expectedResult, sliceutils.Difference(first, second, third))
+}
+
+func TestUnion(t *testing.T) {
+	expectedResult := []int{1, 2, 3, 4, 5, 6, 7}
+
+	first := []int{1, 2, 3, 4, 5}
+	second := []int{2, 3, 4, 5, 6}
+	third := []int{3, 4, 5, 6, 7}
+
+	assert.Equal(t, expectedResult, sliceutils.Union(first, second, third))
+}
+
+func TestReverse(t *testing.T) {
+	expectedResult := []int{9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
+	assert.Equal(t, expectedResult, sliceutils.Reverse(numerals))
+	// ensure does not modify the original
+	assert.Equal(t, expectedResult, sliceutils.Reverse(numerals))
+
+	// test basic odd length case
+	expectedResult = []int{9, 8, 7, 6, 5, 4, 3, 2, 1}
+	assert.Equal(t, expectedResult, sliceutils.Reverse(numerals[1:]))
+}
+
+func TestUnique(t *testing.T) {
+	duplicates := []int{6, 6, 6, 9, 0, 0, 0}
+	expectedResult := []int{6, 9, 0}
+	assert.Equal(t, expectedResult, sliceutils.Unique(duplicates))
+	// Ensure original is unaltered
+	assert.NotEqual(t, expectedResult, duplicates)
+}
+
+func TestChunk(t *testing.T) {
+	numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	assert.Equal(t, [][]int{{1, 2}, {3, 4}, {5, 6}, {7, 8}, {9, 10}}, sliceutils.Chunk(numbers, 2))
+	assert.Equal(t, [][]int{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10}}, sliceutils.Chunk(numbers, 3))
+}
+
+func TestPluck(t *testing.T) {
+	items := []Pluckable{
+		{
+			Code:  "azer",
+			Value: "Azer",
+		},
+		{
+			Code:  "tyuio",
+			Value: "Tyuio",
+		},
+	}
+
+	assert.Equal(t, []string{"azer", "tyuio"}, sliceutils.Pluck(items, func(item Pluckable) *string {
+		return &item.Code
+	}))
+	assert.Equal(t, []string{"Azer", "Tyuio"}, sliceutils.Pluck(items, func(item Pluckable) *string {
+		return &item.Value
+	}))
+}
+
+func TestFlatten(t *testing.T) {
+	items := [][]int{
+		{1, 2, 3, 4},
+		{5, 6},
+		{7, 8},
+		{9, 10, 11},
+	}
+
+	flattened := sliceutils.Flatten(items)
+
+	assert.Equal(t, []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}, flattened)
+
+	assert.Nil(t, sliceutils.Flatten([][]int{}))
+	assert.Nil(t, sliceutils.Flatten([][]int(nil)))
+
+	assert.Nil(t, sliceutils.Flatten([][]int{{}, {}}))
+	assert.Nil(t, sliceutils.Flatten([][]int{nil, nil}))
+
+	assert.Nil(t, sliceutils.Flatten([][]int{{}, nil}))
+}

tag.bat

@@ -1,4 +1,4 @@
-git tag v1.1.4
+git tag v1.1.5
 git tag bank_card/v1.1.0
 git tag entgo/v1.1.6
 git tag geoip/v1.1.0