From 8362ac7a1f9f25cecb41a149e18c2dd0be51a1c8 Mon Sep 17 00:00:00 2001
From: Ran Nozik <nozik86@gmail.com>
Date: Wed, 18 Aug 2021 12:51:53 +0300
Subject: [PATCH] minor fix

---
 .../src/instrumentation.ts                    | 29 +++++++++++--------
 .../src/types.ts                              |  7 ++---
 .../test/mongodb.test.ts                      |  3 ++
 3 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/plugins/node/opentelemetry-instrumentation-mongodb/src/instrumentation.ts b/plugins/node/opentelemetry-instrumentation-mongodb/src/instrumentation.ts
index ecc4619050..ad1780d996 100644
--- a/plugins/node/opentelemetry-instrumentation-mongodb/src/instrumentation.ts
+++ b/plugins/node/opentelemetry-instrumentation-mongodb/src/instrumentation.ts
@@ -160,7 +160,7 @@ export class MongoDBInstrumentation extends InstrumentationBase<
           ns,
           server,
           // eslint-disable-next-line @typescript-eslint/no-explicit-any
-          (ops[0] as any)
+          ops[0] as any
         );
         const patchedCallback = instrumentation._patchEnd(span, resultHandler);
         // handle when options is the callback to send the correct number of args
@@ -412,20 +412,25 @@ export class MongoDBInstrumentation extends InstrumentationBase<
     const commandObj = command.query ?? command.q ?? command;
     const dbStatementSerializer: DbStatementSerializer =
       this._config.dbStatementSerializer ||
-      this.defaultDbStatementSerializer.bind(this);
+      this._defaultDbStatementSerializer.bind(this);
 
-    safeExecuteInTheMiddle(() => {
-      const query = dbStatementSerializer(commandObj);
-      span.setAttribute(SemanticAttributes.DB_STATEMENT, JSON.stringify(query));
-    }, err => {
-      if (err) {
-        diag.error('Error running dbStatementSerializer hook', err);
-      }
-    },
-    true)
+    if (typeof dbStatementSerializer === 'function') {
+      safeExecuteInTheMiddle(
+        () => {
+          const query = dbStatementSerializer(commandObj);
+          span.setAttribute(SemanticAttributes.DB_STATEMENT, query);
+        },
+        err => {
+          if (err) {
+            this._diag.error('Error running dbStatementSerializer hook', err);
+          }
+        },
+        true
+      );
+    }
   }
 
-  private defaultDbStatementSerializer (commandObj: Record<string, unknown>) {
+  private _defaultDbStatementSerializer(commandObj: Record<string, unknown>) {
     const enhancedDbReporting = !!this._config?.enhancedDatabaseReporting;
     const resultObj = enhancedDbReporting
       ? commandObj
diff --git a/plugins/node/opentelemetry-instrumentation-mongodb/src/types.ts b/plugins/node/opentelemetry-instrumentation-mongodb/src/types.ts
index b074407d44..fd54361449 100644
--- a/plugins/node/opentelemetry-instrumentation-mongodb/src/types.ts
+++ b/plugins/node/opentelemetry-instrumentation-mongodb/src/types.ts
@@ -23,14 +23,11 @@ export interface MongoDBInstrumentationExecutionResponseHook {
 
 /**
  * Function that can be used to serialize db.statement tag
- * @param cmdName - The name of the command (eg. set, get, mset)
- * @param cmdArgs - Array of arguments passed to the command
+ * @param cmd - MongoDB command object
  *
  * @returns serialized string that will be used as the db.statement attribute.
  */
- export type DbStatementSerializer = (
-   cmd: Record<string, unknown>
-) => string;
+export type DbStatementSerializer = (cmd: Record<string, unknown>) => string;
 
 export interface MongoDBInstrumentationConfig extends InstrumentationConfig {
   /**
diff --git a/plugins/node/opentelemetry-instrumentation-mongodb/test/mongodb.test.ts b/plugins/node/opentelemetry-instrumentation-mongodb/test/mongodb.test.ts
index 2b5068b089..fe1bd7dc9b 100644
--- a/plugins/node/opentelemetry-instrumentation-mongodb/test/mongodb.test.ts
+++ b/plugins/node/opentelemetry-instrumentation-mongodb/test/mongodb.test.ts
@@ -255,6 +255,9 @@ describe('MongoDBInstrumentation', () => {
       memoryExporter.reset();
       create({
         enhancedDatabaseReporting: true,
+        dbStatementSerializer: (commandObj: Record<string, unknown>) => {
+          return JSON.stringify(commandObj);
+        },
       });
     });