PR requested changes 4

Author: aditi-khare-mongoDB

src/mongo_logger.ts

@@ -219,7 +219,7 @@ export function createStdioLogger(stream: {
   write: NodeJS.WriteStream['write'];
 }): MongoDBLogWritable {
   return {
-    write: promisify((log: Log, cb: () => void): unknown => {
+    write: promisify((log: Log, cb: (error?: Error) => void): unknown => {
       stream.write(inspect(log, { compact: true, breakLength: Infinity }), 'utf-8', cb);
       return;
     })
@@ -418,10 +418,7 @@ export function stringifyWithMaxLen(
   let strToTruncate = '';
 
   try {
-    strToTruncate =
-      typeof value !== 'function'
-        ? EJSON.stringify(value, options)
-        : 'ReadPreference function';
+    strToTruncate = typeof value !== 'function' ? EJSON.stringify(value, options) : value.name;
   } catch (e) {
     strToTruncate = `Extended JSON serialization failed with: ${e.message}`;
   }

src/sdam/server_selection.ts

@@ -22,25 +22,26 @@ export type ServerSelector = (
  * Returns a server selector that selects for writable servers
  */
 export function writableServerSelector(): ServerSelector {
-  return (
+  return function writableServer(
     topologyDescription: TopologyDescription,
     servers: ServerDescription[]
-  ): ServerDescription[] =>
-    latencyWindowReducer(
+  ): ServerDescription[] {
+    return latencyWindowReducer(
       topologyDescription,
       servers.filter((s: ServerDescription) => s.isWritable)
     );
+  };
 }
 
 /**
  * The purpose of this selector is to select the same server, only
  * if it is in a state that it can have commands sent to it.
  */
 export function sameServerSelector(description?: ServerDescription): ServerSelector {
-  return (
+  return function sameServerSelector(
     topologyDescription: TopologyDescription,
     servers: ServerDescription[]
-  ): ServerDescription[] => {
+  ): ServerDescription[] {
     if (!description) return [];
     // Filter the servers to match the provided description only if
     // the type is not unknown.
@@ -265,11 +266,11 @@ export function readPreferenceServerSelector(readPreference: ReadPreference): Se
     throw new MongoInvalidArgumentError('Invalid read preference specified');
   }
 
-  return (
+  return function readPreferenceServers(
     topologyDescription: TopologyDescription,
     servers: ServerDescription[],
     deprioritized: ServerDescription[] = []
-  ): ServerDescription[] => {
+  ): ServerDescription[] {
     const commonWireVersion = topologyDescription.commonWireVersion;
     if (
       commonWireVersion &&

src/utils.ts

@@ -171,7 +171,7 @@ export function applyRetryableWrites<T extends HasRetryableWrites>(target: T, db
  * @param value - An object that could be a promise
  * @returns true if the provided value is a Promise
  */
-export function isPromiseLike<T = any>(value?: unknown): value is Promise<T> {
+export function isPromiseLike<T = any>(value?: unknown): value is PromiseLike<T> {
   return (
     value != null &&
     typeof value === 'object' &&

test/unit/mongo_logger.test.ts

@@ -56,7 +56,7 @@ describe('meta tests for BufferingStream', function () {
   });
 });
 
-describe.only('class MongoLogger', async function () {
+describe('class MongoLogger', async function () {
   describe('#constructor()', function () {
     it('assigns each property from the options object onto the logging class', function () {
       const componentSeverities: MongoLoggerOptions['componentSeverities'] = {
@@ -1315,32 +1315,39 @@ describe.only('class MongoLogger', async function () {
         for (const errorInput of errorInputs) {
           context(`when value is ${errorInput.name}`, function () {
             it('should output default error message, with no error thrown', function () {
-              expect(stringifyWithMaxLen(errorInput.input, 25)).to.equal(
-                '... ESJON failed : Error ...'
+              expect(stringifyWithMaxLen(errorInput.input, 40)).to.equal(
+                'Extended JSON serialization failed with:...'
               );
             });
           });
         }
       });
 
-      context('when given anonymous function as input', function () {
-        it('should output default error message', function () {
-          expect(stringifyWithMaxLen((v: number) => v + 1, DEFAULT_MAX_DOCUMENT_LENGTH)).to.equal(
-            'anonymous function'
-          );
+      context('when given function as input', function () {
+        it('should output function.name', function () {
+          expect(
+            stringifyWithMaxLen(function randomFunc() {
+              return 1;
+            }, DEFAULT_MAX_DOCUMENT_LENGTH)
+          ).to.equal('randomFunc');
         });
       });
     });
   });
 
   describe('log', async function () {
-    const componentSeverities: MongoLoggerOptions['componentSeverities'] = {
-      command: 'trace',
-      topology: 'trace',
-      serverSelection: 'trace',
-      connection: 'trace',
-      client: 'trace'
-    } as any;
+    let componentSeverities: MongoLoggerOptions['componentSeverities'];
+
+    beforeEach(function () {
+      componentSeverities = {
+        command: 'trace',
+        topology: 'trace',
+        serverSelection: 'trace',
+        connection: 'trace',
+        client: 'trace'
+      } as any;
+    });
+
     describe('sync stream failure handling', function () {
       context('when stream is not stderr', function () {
         let stderrStub;