Use a slice of strings for the labels instead of a map[string]struct{}

There seems to be no value having a struct because we store an empty
struct so what gives?
This makes sure that whatever is the order in the query is what we have
for the ordering of labels

CHANGELOG.md

@@ -1,9 +1,14 @@
 # Changelog
 
+## 0.2.1
+
+### Build
+* Fixed issues with ordering of values, we now respect the order specified in the query
+
 ## 0.2.0 
 
 ### Build
 * Update go-rockset-client SDK
 * Update grafana plugin SDK
 * Add e2e tests
-* Move build from CircleCI to Github Actions
+* Move build from CircleCI to Github Actions

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rockset-backend-datasource",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "Rockset backend datasource",
   "scripts": {
     "build": "webpack -c ./.config/webpack/webpack.config.ts --env production",

pkg/rockset.go

@@ -153,9 +153,9 @@ func (d *Datasource) query(ctx context.Context, rs *rockset.RockClient, query ba
 		log.DefaultLogger.Error(errMsg)
 		return backend.ErrDataResponse(backend.StatusUnknown, errMsg)
 	}
-	log.DefaultLogger.Debug("labels", "values", labelValues)
 
-	for label := range labelValues {
+	log.DefaultLogger.Debug("labels", "values", labelValues)
+	for _, label := range labelValues {
 		for i, c := range qr.ColumnFields {
 			// skip the time field and the label column
 			if c.Name == qm.QueryTimeField || c.Name == qm.QueryLabelColumn {
@@ -186,13 +186,13 @@ func (d *Datasource) query(ctx context.Context, rs *rockset.RockClient, query ba
 }
 
 // extract the set of label values from the label column
-func generateLabelValues(labelColumn string, results []map[string]interface{}) (map[string]struct{}, error) {
-	labels := make(map[string]struct{})
+func generateLabelValues(labelColumn string, results []map[string]interface{}) ([]string, error) {
+	labels := make([]string, 0)
+	seen := make(map[string]struct{})
 
 	// if there isn't any label column specified, add an empty string so we can use it as a special case
 	if labelColumn == "" {
-		labels[""] = struct{}{}
-		return labels, nil
+		return []string{""}, nil
 	}
 
 	for _, m := range results {
@@ -206,7 +206,11 @@ func generateLabelValues(labelColumn string, results []map[string]interface{}) (
 			log.DefaultLogger.Error("could not cast label column value to string", "label", label)
 			continue
 		}
-		labels[l] = struct{}{}
+		_, found = seen[l]
+		if !found {
+			labels = append(labels, l)
+			seen[l] = struct{}{}
+		}
 	}
 
 	if len(labels) == 0 {

src/plugin.json

@@ -34,8 +34,8 @@
       }
     ],
     "screenshots": [],
-    "version": "0.2.0",
-    "updated": "2023-01-13"
+    "version": "0.2.1",
+    "updated": "2023-11-05"
   },
   "dependencies": {
     "grafanaDependency": "^9.2.5",