initial POC

Author: baileympearson

src/change_stream.ts

@@ -1073,7 +1073,8 @@ export class ChangeStream<
     try {
       await topology.selectServer(this.cursor.readPreference, {
         operationName: 'reconnect topology in change stream',
-        timeoutContext: this.timeoutContext
+        timeoutContext: this.timeoutContext,
+        deprioritizedServers: []
       });
       this.cursor = this._createChangeStreamCursor(this.cursor.resumeOptions);
     } catch {

test/tools/utils.ts

@@ -285,7 +285,12 @@ export function topologyWithPlaceholderClient(
   options: Partial<TopologyOptions>
 ): Topology {
   return new Topology(
-    new MongoClient('mongodb://iLoveJavaScript'),
+    new MongoClient(
+      'mongodb://iLoveJavaScript',
+      options.serverSelectionTimeoutMS
+        ? { serverSelectionTimeoutMS: options.serverSelectionTimeoutMS }
+        : {}
+    ),
     seeds,
     options as TopologyOptions
   );

test/unit/assorted/server_selection.spec.test.ts

@@ -11,7 +11,7 @@ import {
   runServerSelectionLogicTest
 } from './server_selection_logic_spec_utils';
 
-describe.only('Server Selection Logic (spec)', function () {
+describe('Server Selection Logic (spec)', function () {
   beforeEach(function () {
     if (this.currentTest.title.match(/Possible/)) {
       this.currentTest.skipReason = 'Nodejs driver does not support PossiblePrimary';

test/unit/assorted/server_selection_latency_window_utils.ts

@@ -134,7 +134,10 @@ export async function runServerSelectionLatencyWindowTest(test: ServerSelectionL
   const selectedServers: Server[] = [];
 
   for (let i = 0; i < test.iterations; ++i) {
-    const server: Server = await topology.selectServer(ReadPreference.NEAREST, {});
+    const server: Server = await topology.selectServer(ReadPreference.NEAREST, {
+      deprioritizedServers: [],
+      operationName: 'test operation'
+    });
     selectedServers.push(server);
   }
 

test/unit/assorted/server_selection_spec_helper.js

@@ -137,7 +137,11 @@ export async function executeServerSelectionTest(testDefinition) {
 
   // default to serverSelectionTimeoutMS of `100` for unit tests
   try {
-    const server = await topology.selectServer(selector, { serverSelectionTimeoutMS: 50 });
+    const server = await topology.selectServer(selector, {
+      serverSelectionTimeoutMS: 50,
+      deprioritizedServers: [],
+      operationName: 'test operation'
+    });
 
     if (testDefinition.error) throw new Error('Expected an error, but found none!');
     if (expectedServers.length === 0 && server !== null) {

test/unit/error.test.ts

@@ -383,7 +383,13 @@ describe('MongoErrors', () => {
       );
       return replSet
         .connect()
-        .then(topology => topology.selectServer('primary', { timeoutContext }))
+        .then(topology =>
+          topology.selectServer('primary', {
+            timeoutContext,
+            deprioritizedServers: [],
+            operationName: 'test operation'
+          })
+        )
         .then(server => server.command(op, timeoutContext))
         .then(
           () => expect.fail('expected command to fail'),
@@ -426,7 +432,11 @@ describe('MongoErrors', () => {
           Object.assign({}, RAW_USER_WRITE_CONCERN_CMD),
           {}
         );
-        const server = await topology.selectServer('primary', { timeoutContext });
+        const server = await topology.selectServer('primary', {
+          timeoutContext,
+          deprioritizedServers: [],
+          operationName: 'test operation'
+        });
         try {
           await server.command(op, timeoutContext);
         } catch (err) {

test/unit/sdam/server_selection.test.ts

@@ -50,93 +50,6 @@ describe('server selection', function () {
     ok: 0
   });
 
-  describe('#readPreferenceServerSelector', function () {
-    let selector;
-    let servers;
-
-    context('when the topology is sharded', function () {
-      const topologyDescription = new TopologyDescription(
-        TopologyType.Sharded,
-        new Map(),
-        'test',
-        MIN_SECONDARY_WRITE_WIRE_VERSION,
-        new ObjectId(),
-        MIN_SECONDARY_WRITE_WIRE_VERSION
-      );
-
-      beforeEach(function () {
-        selector = readPreferenceServerSelector(ReadPreference.secondaryPreferred);
-      });
-
-      context('when there are deprioritized servers', function () {
-        context('when there are other servers', function () {
-          beforeEach(function () {
-            servers = selector(topologyDescription, [mongos], [mongosTwo]);
-          });
-
-          it('returns a server from the other servers', function () {
-            expect(servers).to.deep.equal([mongos]);
-          });
-        });
-
-        context('when there are no other servers', function () {
-          beforeEach(function () {
-            servers = selector(topologyDescription, [], [mongosTwo]);
-          });
-
-          it('returns a server from the deprioritized servers', function () {
-            expect(servers).to.deep.equal([mongosTwo]);
-          });
-        });
-      });
-
-      context('when there are no deprioritised servers', function () {
-        beforeEach(function () {
-          servers = selector(topologyDescription, [mongos]);
-        });
-
-        it('returns a server from the other servers', function () {
-          expect(servers).to.deep.equal([mongos]);
-        });
-      });
-    });
-
-    context('when the topology is not sharded', function () {
-      const topologyDescription = new TopologyDescription(
-        TopologyType.ReplicaSetWithPrimary,
-        new Map(),
-        'test',
-        MIN_SECONDARY_WRITE_WIRE_VERSION,
-        new ObjectId(),
-        MIN_SECONDARY_WRITE_WIRE_VERSION
-      );
-
-      beforeEach(function () {
-        selector = readPreferenceServerSelector(ReadPreference.secondary);
-      });
-
-      context('when there are deprioritized servers', function () {
-        beforeEach(function () {
-          servers = selector(topologyDescription, [secondaryTwo], [secondary]);
-        });
-
-        it('selects from all server lists', function () {
-          expect(servers).to.contain.oneOf([secondary, secondaryTwo]);
-        });
-      });
-
-      context('when there are no deprioritised servers', function () {
-        beforeEach(function () {
-          servers = selector(topologyDescription, [secondary], []);
-        });
-
-        it('selects from all non-deprioritised servers', function () {
-          expect(servers).to.deep.equal([secondary]);
-        });
-      });
-    });
-  });
-
   describe('#sameServerSelector', function () {
     const topologyDescription = sinon.stub();
     const serverDescriptions = new Map();

test/unit/sdam/topology.test.ts

@@ -446,11 +446,9 @@ describe('Topology (unit)', function () {
 
   describe('selectServer()', function () {
     it('should schedule monitoring if no suitable server is found', async function () {
-      const topology = topologyWithPlaceholderClient(
-        'someserver:27019',
-        {},
-        { serverSelectionTimeoutMS: 10 }
-      );
+      const topology = topologyWithPlaceholderClient('someserver:27019', {
+        serverSelectionTimeoutMS: 10
+      });
       const requestCheck = sinon.stub(Server.prototype, 'requestCheck');
 
       sinon.stub(Server.prototype, 'connect').callsFake(function () {