Merge pull request samber#60 from muety/muety/patch1

Adding FindOrElse and tests

README.md

@@ -216,7 +216,7 @@ present := lo.Contains[int]([]int{0, 1, 2, 3, 4, 5}, 5)
 // true
 ```
 
-### Contains
+### ContainsBy
 
 Returns true if the predicate function returns `true`.
 

find.go

@@ -2,10 +2,9 @@ package lo
 
 import (
 	"fmt"
+	"golang.org/x/exp/constraints"
 	"math"
 	"math/rand"
-
-	"golang.org/x/exp/constraints"
 )
 
 // import "golang.org/x/exp/constraints"
@@ -76,6 +75,17 @@ func FindLastIndexOf[T any](collection []T, predicate func(T) bool) (T, int, boo
 	return result, -1, false
 }
 
+// FindOrElse search an element in a slice based on a predicate. It returns the element if found or a given fallback value otherwise.
+func FindOrElse[T any](collection []T, fallback T, predicate func(T) bool) T {
+	for _, item := range collection {
+		if predicate(item) {
+			return item
+		}
+	}
+
+	return fallback
+}
+
 // Min search the minimum value of a collection.
 func Min[T constraints.Ordered](collection []T) T {
 	var min T

find_test.go

@@ -82,6 +82,20 @@ func TestFindLastIndexOf(t *testing.T) {
 	is.Equal(index2, -1)
 }
 
+func TestFindOrElse(t *testing.T) {
+	is := assert.New(t)
+
+	result1 := FindOrElse[string]([]string{"a", "b", "c", "d"}, "x", func(i string) bool {
+		return i == "b"
+	})
+	result2 := FindOrElse[string]([]string{"foobar"}, "x", func(i string) bool {
+		return i == "b"
+	})
+
+	is.Equal(result1, "b")
+	is.Equal(result2, "x")
+}
+
 func TestMin(t *testing.T) {
 	is := assert.New(t)
 

slice_test.go

@@ -115,6 +115,24 @@ func TestReduce(t *testing.T) {
 	is.Equal(result2, 20)
 }
 
+func TestForEach(t *testing.T) {
+	is := assert.New(t)
+
+	// check of callback is called for every element and in proper order
+
+	callParams1 := []string{}
+	callParams2 := []int{}
+
+	ForEach[string]([]string{"a", "b", "c"}, func(item string, i int) {
+		callParams1 = append(callParams1, item)
+		callParams2 = append(callParams2, i)
+	})
+
+	is.ElementsMatch([]string{"a", "b", "c"}, callParams1)
+	is.ElementsMatch([]int{0, 1, 2}, callParams2)
+	is.IsIncreasing(callParams2)
+}
+
 func TestUniq(t *testing.T) {
 	is := assert.New(t)