Don't fail when decoding empty strings as floats in server responses

Author: Jan Waś

trino/trino.go

@@ -713,27 +713,27 @@ type stmtResponse struct {
 }
 
 type stmtStats struct {
-	State                string    `json:"state"`
-	Scheduled            bool      `json:"scheduled"`
-	Nodes                int       `json:"nodes"`
-	TotalSplits          int       `json:"totalSplits"`
-	QueuesSplits         int       `json:"queuedSplits"`
-	RunningSplits        int       `json:"runningSplits"`
-	CompletedSplits      int       `json:"completedSplits"`
-	UserTimeMillis       int       `json:"userTimeMillis"`
-	CPUTimeMillis        int64     `json:"cpuTimeMillis"`
-	WallTimeMillis       int64     `json:"wallTimeMillis"`
-	QueuedTimeMillis     int64     `json:"queuedTimeMillis"`
-	ElapsedTimeMillis    int64     `json:"elapsedTimeMillis"`
-	ProcessedRows        int64     `json:"processedRows"`
-	ProcessedBytes       int64     `json:"processedBytes"`
-	PhysicalInputBytes   int64     `json:"physicalInputBytes"`
-	PhysicalWrittenBytes int64     `json:"physicalWrittenBytes"`
-	PeakMemoryBytes      int64     `json:"peakMemoryBytes"`
-	SpilledBytes         int64     `json:"spilledBytes"`
-	RootStage            stmtStage `json:"rootStage"`
-	ProgressPercentage   float32   `json:"progressPercentage"`
-	RunningPercentage    float32   `json:"runningPercentage"`
+	State                string      `json:"state"`
+	Scheduled            bool        `json:"scheduled"`
+	Nodes                int         `json:"nodes"`
+	TotalSplits          int         `json:"totalSplits"`
+	QueuesSplits         int         `json:"queuedSplits"`
+	RunningSplits        int         `json:"runningSplits"`
+	CompletedSplits      int         `json:"completedSplits"`
+	UserTimeMillis       int         `json:"userTimeMillis"`
+	CPUTimeMillis        int64       `json:"cpuTimeMillis"`
+	WallTimeMillis       int64       `json:"wallTimeMillis"`
+	QueuedTimeMillis     int64       `json:"queuedTimeMillis"`
+	ElapsedTimeMillis    int64       `json:"elapsedTimeMillis"`
+	ProcessedRows        int64       `json:"processedRows"`
+	ProcessedBytes       int64       `json:"processedBytes"`
+	PhysicalInputBytes   int64       `json:"physicalInputBytes"`
+	PhysicalWrittenBytes int64       `json:"physicalWrittenBytes"`
+	PeakMemoryBytes      int64       `json:"peakMemoryBytes"`
+	SpilledBytes         int64       `json:"spilledBytes"`
+	RootStage            stmtStage   `json:"rootStage"`
+	ProgressPercentage   jsonFloat64 `json:"progressPercentage"`
+	RunningPercentage    jsonFloat64 `json:"runningPercentage"`
 }
 
 type ErrTrino struct {
@@ -792,6 +792,28 @@ type stmtStage struct {
 	SubStages       []stmtStage `json:"subStages"`
 }
 
+type jsonFloat64 float64
+
+func (f *jsonFloat64) UnmarshalJSON(data []byte) error {
+	var v float64
+	err := json.Unmarshal(data, &v)
+	if err != nil {
+		var jsonErr *json.UnmarshalTypeError
+		if errors.As(err, &jsonErr) {
+			if f != nil {
+				*f = 0
+			}
+			return nil
+		}
+		return err
+	}
+	p := (*float64)(f)
+	*p = v
+	return nil
+}
+
+var _ json.Unmarshaler = new(jsonFloat64)
+
 func (st *driverStmt) Query(args []driver.Value) (driver.Rows, error) {
 	return nil, driver.ErrSkip
 }

trino/trino_test.go

@@ -250,6 +250,34 @@ func TestRoundTripRetryQueryError(t *testing.T) {
 	assert.IsTypef(t, new(ErrQueryFailed), err, "unexpected error: %w", err)
 }
 
+func TestRoundTripBogusData(t *testing.T) {
+	count := 0
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if count == 0 {
+			count++
+			w.WriteHeader(http.StatusServiceUnavailable)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+		// some invalid JSON
+		w.Write([]byte(`{"stats": {"progressPercentage": ""}}`))
+	}))
+
+	t.Cleanup(ts.Close)
+
+	db, err := sql.Open("trino", ts.URL)
+	require.NoError(t, err)
+
+	t.Cleanup(func() {
+		assert.NoError(t, db.Close())
+	})
+
+	rows, err := db.Query("SELECT 1")
+	require.NoError(t, err)
+	assert.False(t, rows.Next())
+	require.NoError(t, rows.Err())
+}
+
 func TestRoundTripCancellation(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusServiceUnavailable)
@@ -336,10 +364,12 @@ func TestQueryForUsername(t *testing.T) {
 }
 
 type TestQueryProgressCallback struct {
-	statusMap map[time.Time]string
+	progressMap map[time.Time]float64
+	statusMap   map[time.Time]string
 }
 
 func (qpc *TestQueryProgressCallback) Update(qpi QueryProgressInfo) {
+	qpc.progressMap[time.Now()] = float64(qpi.QueryStats.ProgressPercentage)
 	qpc.statusMap[time.Now()] = qpi.QueryStats.State
 }
 
@@ -387,9 +417,11 @@ func TestQueryProgressWithCallbackPeriod(t *testing.T) {
 		assert.NoError(t, db.Close())
 	})
 
+	progressMap := make(map[time.Time]float64)
 	statusMap := make(map[time.Time]string)
 	progressUpdater := &TestQueryProgressCallback{
-		statusMap: statusMap,
+		progressMap: progressMap,
+		statusMap:   statusMap,
 	}
 	progressUpdaterPeriod, err := time.ParseDuration("1ms")
 	require.NoError(t, err)
@@ -416,6 +448,8 @@ func TestQueryProgressWithCallbackPeriod(t *testing.T) {
 	}
 
 	// sort time in order to calculate interval
+	assert.NotEmpty(t, progressMap)
+	assert.NotEmpty(t, statusMap)
 	var keys []time.Time
 	for k := range statusMap {
 		keys = append(keys, k)
@@ -428,6 +462,7 @@ func TestQueryProgressWithCallbackPeriod(t *testing.T) {
 		if i > 0 {
 			assert.GreaterOrEqual(t, k.Sub(keys[i-1]), progressUpdaterPeriod)
 		}
+		assert.GreaterOrEqual(t, progressMap[k], 0.0)
 	}
 }