Added FilterMap

moslice/filter_test.go

@@ -1,10 +1,12 @@
 package moslice_test
 
 import (
-	"lmika.dev/pkg/modash/moslice"
+	"fmt"
 	"strings"
 	"testing"
 
+	"lmika.dev/pkg/modash/moslice"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -27,3 +29,23 @@ func TestFilter(t *testing.T) {
 		assert.Equal(t, []int{}, moslice.Filter([]int{}, func(x int) bool { return x%2 == 0 }))
 	})
 }
+
+func TestFilterMap(t *testing.T) {
+	var (
+		ints = []int{1, 2, 3, 4, 5}
+		strs = []string{"foo", "bar", "baz"}
+	)
+
+	t.Run("should filter items matching the predicate", func(t *testing.T) {
+		assert.Equal(t, []string{"2", "4"}, moslice.FilterMap(ints, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+		assert.Equal(t, []int{3, 3}, moslice.FilterMap(strs, func(x string) (int, bool) { return len(x), strings.Contains(x, "b") }))
+	})
+
+	t.Run("should moslice nil if the passed in slice is nil", func(t *testing.T) {
+		assert.Nil(t, moslice.FilterMap(nil, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+	})
+
+	t.Run("should return empty slice if the passed in slice is empty slice", func(t *testing.T) {
+		assert.Equal(t, []string{}, moslice.FilterMap([]int{}, func(x int) (string, bool) { return fmt.Sprint(x), x%2 == 0 }))
+	})
+}