Loki: Parse query with unwrap (#47282)

* Loki: Parse simple unwrap

* Update public/app/plugins/datasource/loki/querybuilder/parsing.ts

* Simplify

public/app/plugins/datasource/loki/querybuilder/parsing.test.ts

@@ -142,6 +142,27 @@ describe('buildVisualQueryFromString', () => {
     );
   });
 
+  it('parses query with with simple unwrap', () => {
+    expect(
+      buildVisualQueryFromString('sum_over_time({app="frontend"} | logfmt | unwrap bytes_processed [1m])')
+    ).toEqual(
+      noErrors({
+        labels: [
+          {
+            op: '=',
+            value: 'frontend',
+            label: 'app',
+          },
+        ],
+        operations: [
+          { id: 'logfmt', params: [] },
+          { id: 'unwrap', params: ['bytes_processed'] },
+          { id: 'sum_over_time', params: ['1m'] },
+        ],
+      })
+    );
+  });
+
   it('parses metrics query with function', () => {
     expect(buildVisualQueryFromString('rate({app="frontend"} | json [5m])')).toEqual(
       noErrors({

public/app/plugins/datasource/loki/querybuilder/parsing.ts

@@ -84,6 +84,11 @@ export function handleExpression(expr: string, node: SyntaxNode, context: Contex
       break;
     }
 
+    case 'UnwrapExpr': {
+      visQuery.operations.push(getUnwrap(expr, node));
+      break;
+    }
+
     case 'RangeAggregationExpr': {
       visQuery.operations.push(handleRangeAggregation(expr, node, context));
       break;
@@ -241,6 +246,16 @@ function getLabelFormat(expr: string, node: SyntaxNode): QueryBuilderOperation {
   };
 }
 
+function getUnwrap(expr: string, node: SyntaxNode): QueryBuilderOperation {
+  const id = 'unwrap';
+  const string = getString(expr, node.getChild('Identifier'));
+
+  return {
+    id,
+    params: [string],
+  };
+}
+
 function handleRangeAggregation(expr: string, node: SyntaxNode, context: Context) {
   const nameNode = node.getChild('RangeOp');
   const funcName = getString(expr, nameNode);