[v9.4.x] SQL Datasources: Prevent Call Stack Overflows with Large Numbers of Values for Variable (#65182)

SQL Datasources: Prevent Call Stack Overflows with Large Numbers of Values for Variable (#64937)

* Push values with every map call to avoid hitting the maximum call stack size.

* Add test and refactor to for of

* Use native fill instead of lodash

---------

Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>
(cherry picked from commit bf687fff45)

Co-authored-by: Kyle Cunningham <codeincarnate@users.noreply.github.com>

public/app/features/plugins/sql/ResponseParser.test.ts

@@ -0,0 +1,23 @@
+import { DataFrameDTO, FieldType, MutableDataFrame } from '@grafana/data';
+
+import { ResponseParser } from './ResponseParser';
+
+describe('transformMetricFindResponse function', () => {
+  it('should handle big arrays', () => {
+    const responseParser = new ResponseParser();
+    const stringValues = new Array(150_000).fill('a');
+    const numberValues = new Array(150_000).fill(1);
+
+    const frame: DataFrameDTO = {
+      fields: [
+        { name: 'name', type: FieldType.string, values: stringValues },
+        { name: 'value', type: FieldType.number, values: numberValues },
+      ],
+    };
+
+    const dataFrame = new MutableDataFrame(frame);
+    const result = responseParser.transformMetricFindResponse(dataFrame);
+
+    expect(result).toHaveLength(2);
+  });
+});

public/app/features/plugins/sql/ResponseParser.ts

@@ -14,13 +14,11 @@ export class ResponseParser implements ResponseParserType {
         values.push({ text: '' + textField.values.get(i), value: '' + valueField.values.get(i) });
       }
     } else {
-      values.push(
-        ...frame.fields
-          .flatMap((f) => f.values.toArray())
-          .map((v) => ({
-            text: v,
-          }))
-      );
+      for (const field of frame.fields) {
+        for (const value of field.values.toArray()) {
+          values.push({ text: value });
+        }
+      }
     }
 
     return uniqBy(values, 'text');