fix(ReadPreference): improve ReadPreference error message and remove irrelevant sharding test

Author: kvwalker

lib/core/topologies/read_preference.js

@@ -13,7 +13,7 @@
  */
 const ReadPreference = function(mode, tags, options) {
   if (!ReadPreference.isValid(mode)) {
-    throw new TypeError(`provided mode ${mode} is an invalid ReadPreference mode`);
+    throw new TypeError(`Invalid read preference mode ${mode}`);
   }
 
   // TODO(major): tags MUST be an array of tagsets
@@ -81,8 +81,6 @@ const VALID_MODES = [
   ReadPreference.SECONDARY,
   ReadPreference.SECONDARY_PREFERRED,
   ReadPreference.NEAREST,
-  // true,
-  // false,
   null
 ];
 

test/functional/readpreference_tests.js

@@ -555,7 +555,7 @@ describe('ReadPreference', function() {
     client.connect((err, client) => {
       const db = client.db(configuration.db);
       expect(db.collection.bind(db, 'test', { readPreference: 'invalid' })).to.throw(
-        'provided mode invalid is an invalid ReadPreference mode'
+        'Invalid read preference mode invalid'
       );
       client.close();
       done();

test/functional/sharding_read_preference_tests.js

@@ -68,62 +68,6 @@ describe('Sharding (Read Preference)', function() {
     }
   });
 
-  /**
-   * @ignore
-   */
-  it('Should correctly fail a Mongos read using a unsupported read preference', {
-    metadata: { requires: { topology: 'sharded' } },
-
-    // The actual test we wish to run
-    test: function(done) {
-      const configuration = this.configuration;
-
-      // Connect using the mongos connections
-      const client = new MongoClient(configuration.url(), { w: 0 });
-      client.connect(function(err) {
-        expect(err).to.not.exist;
-        const db = client.db(configuration.db);
-
-        // Perform a simple insert into a collection
-        const collection = db.collection('shard_test2');
-        // Insert a simple doc
-        collection.insertOne({ test: 1 }, { w: 'majority', wtimeout: 10000 }, function(err) {
-          expect(err).to.not.exist;
-
-          // Set debug level for the driver
-          Logger.setLevel('debug');
-
-          let gotMessage = false;
-          // Get the current logger
-          Logger.setCurrentLogger(function(message, options) {
-            if (
-              options.type === 'debug' &&
-              options.className === 'Cursor' &&
-              options.message.indexOf('"mode":"notsupported"') !== -1
-            ) {
-              gotMessage = true;
-            }
-          });
-
-          collection.findOne(
-            { test: 1 },
-            { readPreference: new ReadPreference('notsupported') },
-            function(err) {
-              expect(err).to.exist;
-              expect(gotMessage).to.equal(true);
-
-              // Set error level for the driver
-              Logger.setLevel('error');
-              // Close db connection
-              client.close();
-              done();
-            }
-          );
-        });
-      });
-    }
-  });
-
   /**
    * @ignore
    */