fix(MongoInstance::checkErrorInLine): hange json output of error "DBException in initAndListen"

Author: hasezoey

packages/mongodb-memory-server-core/src/util/MongoInstance.ts

@@ -591,6 +591,21 @@ export class MongoInstance extends EventEmitter implements ManagerBase {
           )
         );
       }
+
+      // special handling for when mongodb outputs this error as json
+      const execptionMatchJson = /\bDBException in initAndListen,/i.test(line);
+
+      if (execptionMatchJson) {
+        const loadedJSON = JSON.parse(line) ?? {};
+
+        this.emit(
+          MongoInstanceEvents.instanceError,
+          new StdoutInstanceError(
+            `Instance Failed to start with "DBException in initAndListen". Original Error:\n` +
+              loadedJSON?.attr?.error ?? line // try to use the parsed json, but as fallback use the entire line
+          )
+        );
+      }
     }
 
     if (/CURL_OPENSSL_3['\s]+not found/i.test(line)) {

packages/mongodb-memory-server-core/src/util/__tests__/MongoInstance.test.ts

@@ -485,6 +485,24 @@ describe('MongodbInstance', () => {
           assertIsError(event); // has to be used, because there is not typeguard from "expect(variable).toBeInstanceOf"
           expect(event.message).toMatchSnapshot();
         });
+
+        it('DBException in initAndListen', () => {
+          // actual line copied from mongod 6.1.0
+          // can be reproduced with "mongodb --storageEngine ephemeralForTest"
+          const line =
+            '{"t":{"$date":"2022-09-01T08:54:54.598+00:00"},"s":"E",  "c":"CONTROL",  "id":20557,   "ctx":"initandlisten","msg":"DBException in initAndListen, terminating","attr":{"error":"Location18656: Cannot start server with an unknown storage engine: ephemeralForTest"}}';
+
+          mongod.stdoutHandler(line);
+
+          console.log(events);
+          expect(events.size).toEqual(2);
+          expect(events.get(MongoInstanceEvents.instanceSTDOUT)).toEqual(line);
+
+          const event = events.get(MongoInstanceEvents.instanceError);
+          expect(event).toBeInstanceOf(StdoutInstanceError);
+          assertIsError(event); // has to be used, because there is not typeguard from "expect(variable).toBeInstanceOf"
+          expect(event.message).toMatchSnapshot();
+        });
       });
     });
 

packages/mongodb-memory-server-core/src/util/__tests__/__snapshots__/MongoInstance.test.ts.snap

@@ -8,6 +8,11 @@ exports[`MongodbInstance prepareCommandArgs should throw an error if no port is
 
 exports[`MongodbInstance test events checkErrorInLine() should emit "instanceError" when shared libraries fail to load 1`] = `"Instance failed to start because a library is missing or cannot be opened: \\"libcrypto.so.1.1\\""`;
 
+exports[`MongodbInstance test events stdoutHandler() should emit "instanceError" when "excepetion in initAndListen" is thrown DBException in initAndListen 1`] = `
+"Instance Failed to start with \\"DBException in initAndListen\\". Original Error:
+Location18656: Cannot start server with an unknown storage engine: ephemeralForTest"
+`;
+
 exports[`MongodbInstance test events stdoutHandler() should emit "instanceError" when "excepetion in initAndListen" is thrown DbPathInUse (Not a directory) 1`] = `
 "Instance Failed to start with \\"DBPathInUse\\". Original Error:
 Unable to create/open the lock file: /dev/null/mongod.lock (Not a directory). Ensure the user executing mongod is the owner of the lock file and has the appropriate permissions. Also make sure that another mongod instance is not already running on the /dev/null directory"