Loki: Fix incorrect TopK value type in query builder (#52226)

* Loki: Fix incorrect TopK value type in query builder

* Simplify code

* Remove bracket

* Brackets are back

public/app/plugins/datasource/prometheus/querybuilder/shared/operationUtils.test.ts

@@ -124,4 +124,43 @@ describe('createAggregationOperationWithParams', () => {
       },
     ]);
   });
+  it('returns correct query string using aggregation definitions with overrides and number type param', () => {
+    const def = createAggregationOperationWithParam(
+      'test_aggregation',
+      {
+        params: [{ name: 'K-value', type: 'number' }],
+        defaultParams: [5],
+      },
+      { category: 'test_category' }
+    );
+
+    const topKByDefinition = def[1];
+    expect(
+      topKByDefinition.renderer(
+        { id: '__topk_by', params: ['5', 'source', 'place'] },
+        def[1],
+        'rate({place="luna"} |= `` [5m])'
+      )
+    ).toBe('test_aggregation by(source, place) (5, rate({place="luna"} |= `` [5m]))');
+  });
+
+  it('returns correct query string using aggregation definitions with overrides and string type param', () => {
+    const def = createAggregationOperationWithParam(
+      'test_aggregation',
+      {
+        params: [{ name: 'Identifier', type: 'string' }],
+        defaultParams: ['count'],
+      },
+      { category: 'test_category' }
+    );
+
+    const countValueDefinition = def[1];
+    expect(
+      countValueDefinition.renderer(
+        { id: 'count_values', params: ['5', 'source', 'place'] },
+        def[1],
+        'rate({place="luna"} |= `` [5m])'
+      )
+    ).toBe('test_aggregation by(source, place) ("5", rate({place="luna"} |= `` [5m]))');
+  });
 });

public/app/plugins/datasource/prometheus/querybuilder/shared/operationUtils.ts

@@ -279,15 +279,13 @@ function getAggregationExplainer(aggregationName: string, mode: 'by' | 'without'
 
 function getAggregationByRendererWithParameter(aggregation: string) {
   return function aggregationRenderer(model: QueryBuilderOperation, def: QueryBuilderOperationDef, innerExpr: string) {
-    function mapType(p: QueryBuilderOperationParamValue) {
-      if (typeof p === 'string') {
-        return `\"${p}\"`;
-      }
-      return p;
-    }
-    const params = model.params.slice(0, -1);
-    const restParams = model.params.slice(1);
-    return `${aggregation} by(${restParams.join(', ')}) (${params.map(mapType).join(', ')}, ${innerExpr})`;
+    const restParamIndex = def.params.findIndex((param) => param.restParam);
+    const params = model.params.slice(0, restParamIndex);
+    const restParams = model.params.slice(restParamIndex);
+
+    return `${aggregation} by(${restParams.join(', ')}) (${params
+      .map((param, idx) => (def.params[idx].type === 'string' ? `\"${param}\"` : param))
+      .join(', ')}, ${innerExpr})`;
   };
 }