Fix Driver.supportsMultiDb return type (#740)

Also add a explicity return type for `supportsTransactionConfig`

Author: bigmontz

core/src/driver.ts

@@ -159,7 +159,7 @@ class Driver {
    *
    * @returns {Promise<boolean>} promise resolved with a boolean or rejected with error.
    */
-  supportsMultiDb(): Promise<Boolean> {
+  supportsMultiDb(): Promise<boolean> {
     const connectionProvider = this._getOrCreateConnectionProvider()
     return connectionProvider.supportsMultiDb()
   }
@@ -172,7 +172,7 @@ class Driver {
    *
    * @returns {Promise<boolean>} promise resolved with a boolean or rejected with error.
    */
-  supportsTransactionConfig() {
+  supportsTransactionConfig(): Promise<boolean> {
     const connectionProvider = this._getOrCreateConnectionProvider()
     return connectionProvider.supportsTransactionConfig()
   }

core/test/driver.test.ts

@@ -0,0 +1,95 @@
+/**
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { ConnectionProvider, newError } from '../src'
+import Driver from '../src/driver'
+import { Logger } from '../src/internal/logger'
+import { ConfiguredCustomResolver } from '../src/internal/resolver'
+
+describe('Driver', () => {
+  let driver: Driver | null
+  let connectionProvider: ConnectionProvider
+  const META_INFO = {
+    routing: false,
+    typename: '',
+    address: 'localhost'
+  }
+  const CONFIG = {}
+
+  beforeEach(() => {
+    connectionProvider = new ConnectionProvider()
+    connectionProvider.close = jest.fn(() => Promise.resolve())
+    driver = new Driver(
+      META_INFO,
+      CONFIG,
+      mockCreateConnectonProvider(connectionProvider)
+    )
+  })
+
+  afterEach(async () => {
+    if (driver) {
+      await driver.close()
+      driver = null
+    }
+  })
+
+  it.each([
+    ['Promise.resolve(true)', Promise.resolve(true)],
+    ['Promise.resolve(false)', Promise.resolve(false)],
+    [
+      "Promise.reject(newError('something went wrong'))",
+      Promise.reject(newError('something went wrong'))
+    ]
+  ])('.supportsMultiDb() => %s', (_, expectedPromise) => {
+    connectionProvider.supportsMultiDb = jest.fn(() => expectedPromise)
+
+    const promise: Promise<boolean> = driver!.supportsMultiDb()
+
+    expect(promise).toBe(expectedPromise)
+
+    promise.catch(_ => 'Do nothing').finally(() => {})
+  })
+
+  it.each([
+    ['Promise.resolve(true)', Promise.resolve(true)],
+    ['Promise.resolve(false)', Promise.resolve(false)],
+    [
+      "Promise.reject(newError('something went wrong'))",
+      Promise.reject(newError('something went wrong'))
+    ]
+  ])('.supportsTransactionConfig() => %s', (_, expectedPromise) => {
+    connectionProvider.supportsTransactionConfig = jest.fn(
+      () => expectedPromise
+    )
+
+    const promise: Promise<boolean> = driver!.supportsTransactionConfig()
+
+    expect(promise).toBe(expectedPromise)
+
+    promise.catch(_ => 'Do nothing').finally(() => {})
+  })
+
+  function mockCreateConnectonProvider(connectionProvider: ConnectionProvider) {
+    return (
+      id: number,
+      config: Object,
+      log: Logger,
+      hostNameResolver: ConfiguredCustomResolver
+    ) => connectionProvider
+  }
+})