joinby_groupjoinby_test.go

package linq

import (
	"testing"

	"github.com/ahmetb/go-linq/v3"
)

func JoinBy(outer linq.Query, inner linq.Query, predicate func(interface{}, interface{}) bool) linq.Query {
	var innerCopy []interface{}
	inner.ToSlice(&innerCopy)
	q := outer.SelectManyBy(func(x interface{}) linq.Query {
		return linq.From(innerCopy)
	}, func(inneritem interface{}, outeritem interface{}) interface{} {
		return linq.KeyValue{Key: outeritem, Value: inneritem}
	}).Where(func(x interface{}) bool {
		return predicate(x.(linq.KeyValue).Key, x.(linq.KeyValue).Value)
	})
	return q
}

func GroupJoinBy(outer linq.Query, inner linq.Query, predicate func(interface{}, interface{}) bool, selector func(interface{}, []interface{}) interface{}) linq.Query {
	q := JoinBy(outer, inner, predicate).
		GroupBy(
			func(x interface{}) interface{} { return x.(linq.KeyValue).Key },
			func(x interface{}) interface{} { return x.(linq.KeyValue).Value }).
		Select(func(x interface{}) interface{} {
			return selector(x.(linq.Group).Key, x.(linq.Group).Group)
		})
	return q
}

func TestJoinBy(t *testing.T) {
	outer := []int{0, 1, 2}
	inner := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
	want := []interface{}{
		linq.KeyValue{Key: 0, Value: 1},
		linq.KeyValue{Key: 0, Value: 2},
		linq.KeyValue{Key: 0, Value: 3},
		linq.KeyValue{Key: 0, Value: 4},
		linq.KeyValue{Key: 0, Value: 5},
		linq.KeyValue{Key: 0, Value: 6},
		linq.KeyValue{Key: 0, Value: 7},
		linq.KeyValue{Key: 0, Value: 8},
		linq.KeyValue{Key: 0, Value: 9},
		linq.KeyValue{Key: 1, Value: 2},
		linq.KeyValue{Key: 1, Value: 3},
		linq.KeyValue{Key: 1, Value: 4},
		linq.KeyValue{Key: 1, Value: 5},
		linq.KeyValue{Key: 1, Value: 6},
		linq.KeyValue{Key: 1, Value: 7},
		linq.KeyValue{Key: 1, Value: 8},
		linq.KeyValue{Key: 1, Value: 9},
		linq.KeyValue{Key: 2, Value: 3},
		linq.KeyValue{Key: 2, Value: 4},
		linq.KeyValue{Key: 2, Value: 5},
		linq.KeyValue{Key: 2, Value: 6},
		linq.KeyValue{Key: 2, Value: 7},
		linq.KeyValue{Key: 2, Value: 8},
		linq.KeyValue{Key: 2, Value: 9},
	}

	q := JoinBy(linq.From(outer), linq.From(inner), func(x interface{}, y interface{}) bool { return x.(int) < y.(int) })

	if !validateQuery(q, want) {
		t.Errorf("From().JoinBy()=%v expected %v", q.Results(), want)
	}
}

func TestGroupJoinBy(t *testing.T) {
	outer := []int{0, 1, 2}
	inner := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
	want := []interface{}{
		linq.KeyValue{Key: 0, Value: 9},
		linq.KeyValue{Key: 1, Value: 8},
		linq.KeyValue{Key: 2, Value: 7},
	}

	q := GroupJoinBy(
		linq.From(outer),
		linq.From(inner),
		func(i interface{}, j interface{}) bool { return i.(int) < j.(int) },
		func(outer interface{}, inners []interface{}) interface{} {
			return linq.KeyValue{Key: outer, Value: len(inners)}
		})

	if !validateQuery(q, want) {
		t.Errorf("From().GroupJoinBy()=%v expected %v", q.Results(), want)
	}
}

// From github.com/ahmetb/go-linq/setup_test.go
func validateQuery(q linq.Query, output []interface{}) bool {
	next := q.Iterate()

	for _, oitem := range output {
		qitem, _ := next()

		if oitem != qitem {
			return false
		}
	}

	_, ok := next()
	_, ok2 := next()
	return !(ok || ok2)
}