You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: reScorer_test.go
    path of file: ./repos/milvus/internal/proxy
    
    the code of the file until where you have to start completion: package proxy

import (
	"encoding/json"
	"testing"

	"github.com/stretchr/testify/assert"

	"github.com/milvus-io/milvus-proto/go-api/v2/commonpb"
	"github.com/milvus-io/milvus-proto/go-api/v2/milvuspb"
)

func TestRescorer(t *testing.T) {
	t.Run("default scorer", func(t *testing.T) {
		rescorers, err := NewReScorer([]*milvuspb.SearchRequest{{}, {}}, nil)
		as
    
func TestRescorer(t *testing.T) {
	t.Run("default scorer", func(t *testing.T) {
		rescorers, err := NewReScorer([]*milvuspb.SearchRequest{{}, {}}, nil)
		assert.NoError(t, err)
		assert.Equal(t, 2, len(rescorers))
		assert.Equal(t, rrfRankType, rescorers[0].scorerType())
	})

	t.Run("rrf without param", func(t *testing.T) {
		params := make(map[string]float64)
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "rrf"},
			{Key: RankParamsKey, Value: string(b)},
		}

		_, err = NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "k not found in rank_params")
	})

	t.Run("rrf param out of range", func(t *testing.T) {
		params := make(map[string]float64)
		params[RRFParamsKey] = -1
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "rrf"},
			{Key: RankParamsKey, Value: string(b)},
		}

		_, err = NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.Error(t, err)

		params[RRFParamsKey] = maxRRFParamsValue + 1
		b, err = json.Marshal(params)
		assert.NoError(t, err)
		rankParams = []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "rrf"},
			{Key: RankParamsKey, Value: string(b)},
		}

		_, err = NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.Error(t, err)
	})

	t.Run("rrf", func(t *testing.T) {
		params := make(map[string]float64)
		params[RRFParamsKey] = 61
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "rrf"},
			{Key: RankParamsKey, Value: string(b)},
		}

		rescorers, err := NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.NoError(t, err)
		assert.Equal(t, 2, len(rescorers))
		assert.Equal(t, rrfRankType, rescorers[0].scorerType())
		assert.Equal(t, float32(61), rescorers[0].(*rrfScorer).k)
	})

	t.Run("weights without param", func(t *testing.T) {
		params := make(map[string][]float64)
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "weighted"},
			{Key: RankParamsKey, Value: string(b)},
		}

		_, err = NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "not found in rank_params")
	})

	t.Run("weights out of range", func(t *testing.T) {
		weights := []float64{1.2, 2.3}
		params := make(map[string][]float64)
		params[WeightsParamsKey] = weights
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "weighted"},
			{Key: RankParamsKey, Value: string(b)},
		}

		_, err = NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "rank param weight should be in range [0, 1]")
	})

	t.Run("weights", func(t *testing.T) {
		weights := []float64{0.5, 0.2}
		params := make(map[string][]float64)
		params[WeightsParamsKey] = weights
		b, err := json.Marshal(params)
		assert.NoError(t, err)
		rankParams := []*commonpb.KeyValuePair{
			{Key: RankTypeKey, Value: "weighted"},
			{Key: RankParamsKey, Value: string(b)},
		}

		rescorers, err := NewReScorer([]*milvuspb.SearchRequest{{}, {}}, rankParams)
		assert.NoError(t, err)
		assert.Equal(t, 2, len(rescorers))
		assert.Equal(t, weightedRankType, rescorers[0].scorerType())
		assert.Equal(t, float32(weights[0]), rescorers[0].(*weightedScorer).weight)
	})
}