Merge pull request #528 from jharris4/supports-transaction-config

Add driver.supportsTransactionConfig

Author: zhenlineo

src/driver.js

@@ -123,6 +123,19 @@ class Driver {
     return connectionProvider.supportsMultiDb()
   }
 
+  /**
+   * Returns whether the server supports transaction config capabilities based on the protocol
+   * version negotiated via handshake.
+   *
+   * Note that this function call _always_ causes a round-trip to the server.
+   *
+   * @returns {Promise<boolean>} promise resolved with a boolean or rejected with error.
+   */
+  supportsTransactionConfig () {
+    const connectionProvider = this._getOrCreateConnectionProvider()
+    return connectionProvider.supportsTransactionConfig()
+  }
+
   /**
    * Acquire a session to communicate with the database. The session will
    * borrow connections from the underlying connection pool as required and

src/internal/connection-provider-direct.js

@@ -20,7 +20,7 @@
 import PooledConnectionProvider from './connection-provider-pooled'
 import DelegateConnection from './connection-delegate'
 import ChannelConnection from './connection-channel'
-import { BOLT_PROTOCOL_V4 } from './constants'
+import { BOLT_PROTOCOL_V4, BOLT_PROTOCOL_V3 } from './constants'
 
 export default class DirectConnectionProvider extends PooledConnectionProvider {
   constructor ({ id, config, log, address, userAgent, authToken }) {
@@ -39,7 +39,7 @@ export default class DirectConnectionProvider extends PooledConnectionProvider {
       .then(connection => new DelegateConnection(connection, null))
   }
 
-  async supportsMultiDb () {
+  async _hasProtocolVersion (versionPredicate) {
     const connection = ChannelConnection.create(
       this._address,
       this._config,
@@ -52,12 +52,24 @@ export default class DirectConnectionProvider extends PooledConnectionProvider {
 
       const protocol = connection.protocol()
       if (protocol) {
-        return protocol.version >= BOLT_PROTOCOL_V4
+        return versionPredicate(protocol.version)
       }
 
       return false
     } finally {
       await connection.close()
     }
   }
+
+  async supportsMultiDb () {
+    return await this._hasProtocolVersion(
+      version => version >= BOLT_PROTOCOL_V4
+    )
+  }
+
+  async supportsTransactionConfig () {
+    return await this._hasProtocolVersion(
+      version => version >= BOLT_PROTOCOL_V3
+    )
+  }
 }

src/internal/connection-provider-routing.js

@@ -33,7 +33,7 @@ import LeastConnectedLoadBalancingStrategy from './least-connected-load-balancin
 import Bookmark from './bookmark'
 import ChannelConnection from './connection-channel'
 import { int } from '../integer'
-import { BOLT_PROTOCOL_V4 } from './constants'
+import { BOLT_PROTOCOL_V4, BOLT_PROTOCOL_V3 } from './constants'
 
 const UNAUTHORIZED_ERROR_CODE = 'Neo.ClientError.Security.Unauthorized'
 const DATABASE_NOT_FOUND_ERROR_CODE =
@@ -152,7 +152,7 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
     }
   }
 
-  async supportsMultiDb () {
+  async _hasProtocolVersion (versionPredicate) {
     const addresses = await this._resolveSeedRouter(this._seedRouter)
 
     let lastError
@@ -169,7 +169,7 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
 
         const protocol = connection.protocol()
         if (protocol) {
-          return protocol.version >= BOLT_PROTOCOL_V4
+          return versionPredicate(protocol.version)
         }
 
         return false
@@ -187,6 +187,18 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
     return false
   }
 
+  async supportsMultiDb () {
+    return await this._hasProtocolVersion(
+      version => version >= BOLT_PROTOCOL_V4
+    )
+  }
+
+  async supportsTransactionConfig () {
+    return await this._hasProtocolVersion(
+      version => version >= BOLT_PROTOCOL_V3
+    )
+  }
+
   forget (address, database) {
     if (database || database === '') {
       this._routingTables[database].forget(address)

src/internal/connection-provider.js

@@ -48,6 +48,16 @@ export default class ConnectionProvider {
     throw new Error('not implemented')
   }
 
+  /**
+   * This method checks whether the backend database supports transaction config functionality
+   * by checking protocol handshake result.
+   *
+   * @returns {Promise<boolean>}
+   */
+  supportsTransactionConfig () {
+    throw new Error('not implemented')
+  }
+
   /**
    * Closes this connection provider along with its internals (connections, pools, etc.)
    *

test/internal/node/direct.driver.boltkit.test.js

@@ -418,7 +418,7 @@ describe('#stub-direct direct driver with stub server', () => {
       }
 
       const server = await boltStub.start(
-        `./test/resources/boltstub/${version}/supports_multi_db.script`,
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
         9001
       )
 
@@ -447,6 +447,44 @@ describe('#stub-direct direct driver with stub server', () => {
     })
   })
 
+  describe('should report whether transaction config is supported', () => {
+    async function verifySupportsTransactionConfig (version, expected) {
+      if (!boltStub.supported) {
+        return
+      }
+
+      const server = await boltStub.start(
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
+        9001
+      )
+
+      const driver = boltStub.newDriver('bolt://127.0.0.1:9001')
+
+      await expectAsync(driver.supportsTransactionConfig()).toBeResolvedTo(
+        expected
+      )
+
+      await driver.close()
+      await server.exit()
+    }
+
+    it('v1', () => verifySupportsTransactionConfig('v1', false))
+    it('v2', () => verifySupportsTransactionConfig('v2', false))
+    it('v3', () => verifySupportsTransactionConfig('v3', true))
+    it('v4', () => verifySupportsTransactionConfig('v4', true))
+    it('on error', async () => {
+      const driver = boltStub.newDriver('bolt://127.0.0.1:9001')
+
+      await expectAsync(driver.supportsTransactionConfig()).toBeRejectedWith(
+        jasmine.objectContaining({
+          code: SERVICE_UNAVAILABLE
+        })
+      )
+
+      await driver.close()
+    })
+  })
+
   describe('should allow to change fetch size', () => {
     async function verifyFailureOnCommit (version) {
       if (!boltStub.supported) {

test/internal/node/routing.driver.boltkit.test.js

@@ -2339,7 +2339,7 @@ describe('#stub-routing routing driver with stub server', () => {
       }
 
       const server = await boltStub.start(
-        `./test/resources/boltstub/${version}/supports_multi_db.script`,
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
         9001
       )
 
@@ -2357,7 +2357,7 @@ describe('#stub-routing routing driver with stub server', () => {
       }
 
       const server = await boltStub.start(
-        `./test/resources/boltstub/${version}/supports_multi_db.script`,
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
         9001
       )
 
@@ -2396,6 +2396,81 @@ describe('#stub-routing routing driver with stub server', () => {
     })
   })
 
+  describe('should report whether transaction config is supported', () => {
+    async function verifySupportsTransactionConfig (version, expected) {
+      if (!boltStub.supported) {
+        return
+      }
+
+      const server = await boltStub.start(
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
+        9001
+      )
+
+      const driver = boltStub.newDriver('neo4j://127.0.0.1:9001')
+
+      await expectAsync(driver.supportsTransactionConfig()).toBeResolvedTo(
+        expected
+      )
+
+      await driver.close()
+      await server.exit()
+    }
+
+    async function verifySupportsTransactionConfigWithResolver (
+      version,
+      expected
+    ) {
+      if (!boltStub.supported) {
+        return
+      }
+
+      const server = await boltStub.start(
+        `./test/resources/boltstub/${version}/supports_protocol_version.script`,
+        9001
+      )
+
+      const driver = boltStub.newDriver('neo4j://127.0.0.1:8000', {
+        resolver: address => [
+          'neo4j://127.0.0.1:9010',
+          'neo4j://127.0.0.1:9005',
+          'neo4j://127.0.0.1:9001'
+        ]
+      })
+
+      await expectAsync(driver.supportsTransactionConfig()).toBeResolvedTo(
+        expected
+      )
+
+      await driver.close()
+      await server.exit()
+    }
+
+    it('v1', () => verifySupportsTransactionConfig('v1', false))
+    it('v2', () => verifySupportsTransactionConfig('v2', false))
+    it('v3', () => verifySupportsTransactionConfig('v3', true))
+    it('v4', () => verifySupportsTransactionConfig('v4', true))
+    it('v1 with resolver', () =>
+      verifySupportsTransactionConfigWithResolver('v1', false))
+    it('v2 with resolver', () =>
+      verifySupportsTransactionConfigWithResolver('v2', false))
+    it('v3 with resolver', () =>
+      verifySupportsTransactionConfigWithResolver('v3', true))
+    it('v4 with resolver', () =>
+      verifySupportsTransactionConfigWithResolver('v4', true))
+    it('on error', async () => {
+      const driver = boltStub.newDriver('neo4j://127.0.0.1:9001')
+
+      await expectAsync(driver.supportsTransactionConfig()).toBeRejectedWith(
+        jasmine.objectContaining({
+          code: SESSION_EXPIRED
+        })
+      )
+
+      await driver.close()
+    })
+  })
+
   async function testAddressPurgeOnDatabaseError (script, query, accessMode) {
     if (!boltStub.supported) {
       return