mongodb-core: fix serialization of BigInt values in query (#3575)

* fixing the BigInt mongo sanitization issue * mongodb-core: adding a test for the BigInt fix --------- Co-authored-by: Amjad Mahfoud <amjad.mahfoud@neofinancial.com>
DataDog · Aug 25, 2023 · 68c46af · 68c46af
1 parent 9cbd635
commit 68c46af
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Showing 2 changed files with 39 additions and 2 deletions.
diff --git a/packages/datadog-plugin-mongodb-core/src/index.js b/packages/datadog-plugin-mongodb-core/src/index.js
@@ -36,10 +36,14 @@ class MongodbCorePlugin extends DatabasePlugin {
   }
 }
 
+function sanitizeBigInt (data) {
+  return JSON.stringify(data, (_key, value) => typeof value === 'bigint' ? value.toString() : value)
+}
+
 function getQuery (cmd) {
   if (!cmd || typeof cmd !== 'object' || Array.isArray(cmd)) return
-  if (cmd.query) return JSON.stringify(limitDepth(cmd.query))
-  if (cmd.filter) return JSON.stringify(limitDepth(cmd.filter))
+  if (cmd.query) return sanitizeBigInt(limitDepth(cmd.query))
+  if (cmd.filter) return sanitizeBigInt(limitDepth(cmd.filter))
 }
 
 function getResource (plugin, ns, query, operationName) {

diff --git a/packages/datadog-plugin-mongodb-core/test/core.spec.js b/packages/datadog-plugin-mongodb-core/test/core.spec.js
@@ -133,6 +133,39 @@ describe('Plugin', () => {
             }, () => {})
           })
 
+          it('should serialize BigInt without erroring', done => {
+            agent
+              .use(traces => {
+                const span = traces[0][0]
+                const resource = `find test.${collection}`
+                const query = `{"_id":"9999999999999999999999"}`
+
+                expect(span).to.have.property('resource', resource)
+                expect(span.meta).to.have.property('mongodb.query', query)
+              })
+              .then(done)
+              .catch(done)
+
+            try {
+              server.command(`test.${collection}`, {
+                find: `test.${collection}`,
+                query: {
+                  _id: 9999999999999999999999n
+                }
+              }, () => {})
+            } catch (err) {
+              // It appears that most versions of MongodDB are happy to use a BigInt instance.
+              // For example, 2.0.0, 3.2.0, 3.1.10, etc.
+              // However, version 3.1.9 throws a synchronous error that it wants a Decimal128 instead.
+              if (err.message.includes('Decimal128')) {
+                // eslint-disable-next-line no-console
+                console.log('This version of mongodb-core does not accept BigInt instances')
+                return done()
+              }
+              done(err)
+            }
+          })
+
           it('should stringify BSON objects', done => {
             const BSON = require(`../../../versions/bson@4.0.0`).get()
             const id = '123456781234567812345678'