each (#10)

* feat: maps map

* ✨: return initial slice

Co-authored-by: Ruidy <rnemausat@newstore.com>

each.go

@@ -1,8 +1,10 @@
 package underscore
 
 // Each iterates over a slice of elements, yielding each in turn to an action function.
-func Each[T any](values []T, action func(T)) {
+// Returns the slice for chaining.
+func Each[T any](values []T, action func(T)) []T {
 	for _, v := range values {
 		action(v)
 	}
+	return values
 }

each_test.go

@@ -20,3 +20,14 @@ func TestEach(t *testing.T) {
 
 	assert.Equal(t, want, res)
 }
+
+func TestEachReturnsInitialSlice(t *testing.T) {
+	names := []string{"Alice", "Bob", "Charles"}
+	want := []string{"Alice", "Bob", "Charles"}
+
+	res := make([]string, 0)
+
+	assert.Equal(t, want, underscore.Each(names, func(n string) {
+		res = append(res, fmt.Sprintf("Hi %s", n))
+	}))
+}