code cleanup following staticcheck (#1701)

Signed-off-by: Guangming Wang <[email protected]>

Author: Guangming Wang

pkg/chunk/inmemory_storage_client.go

@@ -266,9 +266,7 @@ func (m *MockStorage) query(ctx context.Context, query IndexQuery, callback func
 	}
 
 	result := mockReadBatch{}
-	for _, item := range items {
-		result.items = append(result.items, item)
-	}
+	result.items = append(result.items, items...)
 
 	callback(&result)
 	return nil

pkg/chunk/storage/caching_index_client.go

@@ -233,7 +233,6 @@ func (s *cachingIndexClient) cacheStore(ctx context.Context, keys []string, batc
 	}
 
 	s.cache.Store(ctx, hashed, bufs)
-	return
 }
 
 func (s *cachingIndexClient) cacheFetch(ctx context.Context, keys []string) (batches []ReadBatch, missed []string) {

pkg/chunk/table_manager.go

@@ -152,7 +152,7 @@ func (m *TableManager) Start() {
 	m.wait.Add(1)
 	go m.loop()
 
-	if m.bucketClient != nil && m.cfg.RetentionPeriod != 0 && m.cfg.RetentionDeletesEnabled == true {
+	if m.bucketClient != nil && m.cfg.RetentionPeriod != 0 && m.cfg.RetentionDeletesEnabled {
 		m.wait.Add(1)
 		go m.bucketRetentionLoop()
 	}

pkg/ingester/ingester.go

@@ -489,9 +489,7 @@ func (i *Ingester) LabelValues(ctx old_ctx.Context, req *client.LabelValuesReque
 	}
 
 	resp := &client.LabelValuesResponse{}
-	for _, v := range state.index.LabelValues(req.LabelName) {
-		resp.LabelValues = append(resp.LabelValues, v)
-	}
+	resp.LabelValues = append(resp.LabelValues, state.index.LabelValues(req.LabelName)...)
 
 	return resp, nil
 }
@@ -508,9 +506,7 @@ func (i *Ingester) LabelNames(ctx old_ctx.Context, req *client.LabelNamesRequest
 	}
 
 	resp := &client.LabelNamesResponse{}
-	for _, v := range state.index.LabelNames() {
-		resp.LabelNames = append(resp.LabelNames, v)
-	}
+	resp.LabelNames = append(resp.LabelNames, state.index.LabelNames()...)
 
 	return resp, nil
 }

pkg/querier/correctness/simple.go

@@ -78,11 +78,9 @@ func (tc *simpleTestCase) Query(ctx context.Context, client v1.API, selectors st
 		return nil, fmt.Errorf("didn't get matrix from Prom")
 	}
 
-	result := []model.SamplePair{}
+	var result []model.SamplePair
 	for _, stream := range ms {
-		for _, pair := range stream.Values {
-			result = append(result, pair)
-		}
+		result = append(result, stream.Values...)
 	}
 	return result, nil
 }