group_test.go

package underscore

import (
	"reflect"
	"testing"

	"github.com/stretchr/testify/assert"
)

func Benchmark_Group(b *testing.B) {
	for n := 0; n < b.N; n++ {
		dst := make([]int, 0)
		Range(1, benchmarkSize, 1).Group(func(n, _ int) string {
			if n%2 == 0 {
				return "even"
			}
			return "odd"
		}).Value(&dst)
	}
}

func Test_Group(t *testing.T) {
	t.Run("default", func(t *testing.T) {
		res := make(map[string][]int)
		Chain([]int{1, 2, 3, 4, 5}).Group(func(n, _ int) string {
			if n%2 == 0 {
				return "even"
			}
			return "odd"
		}).Value(&res)
		assert.EqualValues(
			t,
			res,
			map[string][]int{
				"odd":  {1, 3, 5},
				"even": {2, 4},
			},
		)
	})

	t.Run("reflect.Value", func(t *testing.T) {
		resValue := reflect.New(
			reflect.MapOf(
				reflect.TypeOf(""),
				reflect.TypeOf([]int{}),
			),
		)
		Chain([]int{1, 2, 3, 4, 5}).Group(func(n, _ int) string {
			if n%2 == 0 {
				return "even"
			}
			return "odd"
		}).Value(resValue)
		assert.EqualValues(
			t,
			resValue.Elem().Interface(),
			map[string][]int{
				"odd":  {1, 3, 5},
				"even": {2, 4},
			},
		)
	})
}

func Test_GroupBy(t *testing.T) {
	t.Run("default", func(t *testing.T) {
		src := []testModel{
			{ID: 1, Name: "a"},
			{ID: 2, Name: "a"},
			{ID: 3, Name: "b"},
			{ID: 4, Name: "b"},
		}
		res := make(map[string][]testModel)
		Chain(src).GroupBy("Name").Value(&res)
		assert.EqualValues(
			t,
			res,
			map[string][]testModel{
				"a": {src[0], src[1]},
				"b": {src[2], src[3]},
			},
		)
	})

	t.Run("reflect.Value", func(t *testing.T) {
		src := []testModel{
			{ID: 1, Name: "a"},
			{ID: 2, Name: "a"},
			{ID: 3, Name: "b"},
			{ID: 4, Name: "b"},
		}
		res := reflect.New(
			reflect.MapOf(
				reflect.TypeOf(src[0].Name),
				reflect.TypeOf(src),
			),
		)
		Chain(src).GroupBy("name").Value(res)
		assert.EqualValues(
			t,
			res.Elem().Interface(),
			map[string][]testModel{
				"a": {src[0], src[1]},
				"b": {src[2], src[3]},
			},
		)
	})
}