fix(instrumentation-pg): preserve SQL template text property

Author: aryamohanan

packages/instrumentation-pg/src/instrumentation.ts

@@ -339,13 +339,15 @@ export class PgInstrumentation extends InstrumentationBase<PgInstrumentationConf
               values: Array.isArray(args[1]) ? args[1] : undefined,
             }
           : firstArgIsQueryObjectWithText
-            ? {
-                ...(arg0 as any),
-                values:
-                  (arg0 as any).values ??
-                  (Array.isArray(args[1]) ? args[1] : undefined),
+          ? (() => {
+              const query = arg0 as any;
+              // If the query object has no values yet, use the second argument as values
+              if (query.values === undefined && Array.isArray(args[1])) {
+                query.values = args[1];
               }
-            : undefined;
+              return query;
+            })()
+          : undefined;
 
         const attributes: Attributes = {
           [ATTR_DB_SYSTEM]: DB_SYSTEM_VALUE_POSTGRESQL,

packages/instrumentation-pg/test/pg.test.ts

@@ -1039,6 +1039,53 @@ describe('pg', () => {
         done();
       });
     });
+
+    it('should handle SQL template literal objects', async () => {
+      const span = tracer.startSpan('test span');
+      await context.with(trace.setSpan(context.active(), span), async () => {
+        // Mock SQLStatement from sql-template-strings library
+        class SQLStatement {
+          strings: string[];
+          values: any[];
+
+          constructor(strings: string[], values: any[]) {
+            this.strings = strings;
+            this.values = values;
+          }
+
+          get text(): string {
+            return this.strings.reduce(
+              (prev: string, curr: string, i: number) => prev + '$' + i + curr
+            );
+          }
+        }
+
+        const name = 'pg_tables';
+        const sqlQuery = new SQLStatement(
+          ['SELECT * FROM information_schema.tables WHERE table_name = ', ''],
+          [name]
+        );
+        const resPromise = await client.query(sqlQuery);
+        assert.ok(resPromise);
+
+        const spans = memoryExporter.getFinishedSpans();
+        assert.strictEqual(spans.length, 1);
+        const pgSpan = spans[0];
+
+        assert.strictEqual(pgSpan.name, 'pg.query:SELECT otel_pg_database');
+        assert.strictEqual(
+          pgSpan.attributes[ATTR_DB_STATEMENT],
+          'SELECT * FROM information_schema.tables WHERE table_name = $1'
+        );
+
+        const executedQueries = getExecutedQueries();
+        assert.ok(executedQueries.length > 0);
+        assert.strictEqual(
+          executedQueries[executedQueries.length - 1].text,
+          'SELECT * FROM information_schema.tables WHERE table_name = $1'
+        );
+      });
+    });
   });
 
   describe('exception event recording', () => {