COMPASS-4353 - Do not report bogus readonly key from collectionStats (#256)

`collStats` does not provide the `readonly` information, so don’t
make up a possibly incorrect value and instead omit the key.

Author: addaleax

lib/native-client.js

@@ -381,7 +381,7 @@ class NativeClient extends EventEmitter {
         this._buildCollectionStats(
           databaseName,
           collectionName,
-          data || { readonly: true }
+          data || {}
         )
       );
     });
@@ -1031,7 +1031,6 @@ class NativeClient extends EventEmitter {
       size: data.size,
       index_details: data.indexDetails || {},
       wired_tiger: data.wiredTiger || {},
-      readonly: data.readonly || false
     };
   }
 

test/native-client.test.js

@@ -406,6 +406,19 @@ describe('NativeClient', function() {
           done();
         });
       });
+
+      // collectionStats() used to provide a `readonly: <boolean>` key, but
+      // since the underlying database command does not provide one, the value
+      // was bogus. Make sure that we're not accidentally providing an incorrect
+      // value.
+      it('does not provide a readonly key', function(done) {
+        client.collectionStats('data-service', 'test', function(err, stats) {
+          assert.equal(null, err);
+          expect(stats.name).to.equal('test');
+          expect(Object.keys(stats)).to.not.include('readonly');
+          done();
+        });
+      });
     });
   });