appium: Unable to switch to WebView context on iOS 12.2

The problem

Since the update to iOS 12.2, I am no longer able to switch into the web-view contexts on iOS Simulators.

Environment

• Appium version (or git revision) that exhibits the issue: 1.13.0
• Desktop OS/version used to run Appium: Mac OSX 10.14.4
• Mobile platform/version under test: iOS 12.2
• Real device or emulator/simulator: Simulator

Details

By using the same app, same appium version, same version of all the appium dependencies but by using iOS 12.1, the issue disappears and I’m able to correctly switch to web-views. By comparing the appium console log of the two executions (the correct one on iOS 12.1 and the failing one on iOS 12.2), it seems like there is a problem on the contexts returned by the AppiumDriver.getContexts() GET method. In particular, it seems like the webview attributes (title, url) are mapped to the native context PID. As a result, the GET method, as you can see in the attached appium log, returns an array composed of the NATIVE_APP context and a WEBVIEW context which actually maps the native context (please notice that the webview name is WEBVIEW_PID_OF_NATIVE_CONTEXT.2, where .2 indicates the second page of a context. As far as I’ve seen so far, in all successful executions the webview contexts end with a .1 suffix). When trying to switch to the returned WEBVIEW, an exception occurs.

Excerpt of the log of the failing execution:

[HTTP] --> GET /wd/hub/session/1db198fa-6984-4550-b09b-326ceb44357b/contexts
[HTTP] {}
[debug] [W3C (1db198fa)] Calling AppiumDriver.getContexts() with args: ["1db198fa-6984-4550-b09b-326ceb44357b"]
[debug] [XCUITest] Executing command 'getContexts'
[debug] [iOS] Getting list of available contexts
[debug] [iOS] Retrieving contexts and views
[debug] [iOS] Selecting by url: false
[debug] [RemoteDebugger] Selecting application
[debug] [RemoteDebugger] Current applications available:
[debug] [RemoteDebugger]     Application: 'PID:57976'
[debug] [RemoteDebugger]         id: "PID:57976"
[debug] [RemoteDebugger]         isProxy: false
[debug] [RemoteDebugger]         name: "myApp"
[debug] [RemoteDebugger]         bundleId: "myAppBundleID"
[debug] [RemoteDebugger]         hostId: undefined
[debug] [RemoteDebugger]         isActive: 2
[debug] [RemoteDebugger]         isAutomationEnabled: false
[debug] [RemoteDebugger]         pageArray:
[debug] [RemoteDebugger]           - id: 2
[debug] [RemoteDebugger]             title: "myTitle" <--- such attributes are mapped on the native context (PID:57976)
[debug] [RemoteDebugger]             url: "myUrl"
[debug] [RemoteDebugger]             isKey: true
[debug] [RemoteDebugger]     Application: 'PID:58003'
[debug] [RemoteDebugger]         id: "PID:58003"
[debug] [RemoteDebugger]         isProxy: true
[debug] [RemoteDebugger]         name: "com.apple.WebKit.WebContent"
[debug] [RemoteDebugger]         bundleId: "com.apple.WebKit.WebContent"
[debug] [RemoteDebugger]         hostId: "PID:57976"
[debug] [RemoteDebugger]         isActive: 1
[debug] [RemoteDebugger]         isAutomationEnabled: false
[debug] [RemoteDebugger]         pageArray: []
[debug] [RemoteDebugger] Found app id key 'PID:57976' for bundle 'myAppBundleID'
[debug] [RemoteDebugger] Found separate bundleId 'com.apple.WebKit.WebContent' acting as proxy for 'myAppBundleID', with app id 'PID:58003'
[debug] [RemoteDebugger] Trying out the possible app ids: PID:57976, PID:58003
[debug] [RemoteDebugger] Selecting app PID:57976 (try #1 of 20)
[debug] [RemoteDebugger] Sending '_rpc_forwardGetListing:' message to remote debugger (id: 71)
[debug] [RemoteDebugger] Received response from socket send: '["PID:57976",{"1":{"WIRPageIdentifierKey":1,"WI...'
[debug] [RemoteDebugger] Received page change notice for app 'PID:57976' but the listing has not changed. Ignoring.
[debug] [RemoteDebugger] Finally selecting app PID:57976: [{"id":2,"title":"myTitle","url":"myUrl","isKey":true}]
[debug] [W3C (1db198fa)] Responding to client with driver.getContexts() result: ["NATIVE_APP","WEBVIEW_57976.2"] <-- the webview points to PID 57976, which is the native context. The suffix .2 is weird
[HTTP] <-- GET /wd/hub/session/1db198fa-6984-4550-b09b-326ceb44357b/contexts 200 7 ms - 42
....
....
....
[HTTP] --> POST /wd/hub/session/1db198fa-6984-4550-b09b-326ceb44357b/context
[HTTP] {"name":"WEBVIEW_57976.2"}
[debug] [W3C (1db198fa)] Calling AppiumDriver.setContext() with args: ["WEBVIEW_57976.2","1db198fa-6984-4550-b09b-326ceb44357b"]
[debug] [XCUITest] Executing command 'setContext'
[debug] [iOS] Attempting to set context to 'WEBVIEW_57976.2'
[debug] [RemoteDebugger] Selecting page '2' on app 'PID:57976' and forwarding socket setup
[debug] [RemoteDebugger] Sending '_rpc_forwardSocketSetup:' message to remote debugger (id: 72)
[debug] [RemoteDebugger] Sender key set
[debug] [RemoteDebugger] Sending '_rpc_forwardSocketData:' message to remote debugger (id: 73)
[debug] [W3C (1db198fa)] Encountered internal error running command: Error: Remote debugger error with code '-32000': Target not found.
[debug] [W3C (1db198fa)]     at Object.errorHandler (/usr/local/lib/node_modules/appium/node_modules/appium-remote-debugger/lib/remote-debugger-rpc-client.js:246:18)
[debug] [W3C (1db198fa)]     at RpcMessageHandler.handleDataMessage (/usr/local/lib/node_modules/appium/node_modules/appium-remote-debugger/lib/remote-debugger-message-handler.js:194:9)
[debug] [W3C (1db198fa)]     at RpcMessageHandler.handleMessage (/usr/local/lib/node_modules/appium/node_modules/appium-remote-debugger/lib/remote-debugger-message-handler.js:77:13)
[debug] [W3C (1db198fa)]     at RemoteDebuggerRpcClient.handleMessage [as receive] (/usr/local/lib/node_modules/appium/node_modules/appium-remote-debugger/lib/remote-debugger-rpc-client.js:394:35)
[debug] [W3C (1db198fa)]     at Socket.emit (events.js:196:13)
[debug] [W3C (1db198fa)]     at addChunk (_stream_readable.js:290:12)
[debug] [W3C (1db198fa)]     at readableAddChunk (_stream_readable.js:271:11)
[debug] [W3C (1db198fa)]     at Socket.Readable.push (_stream_readable.js:226:10)
[debug] [W3C (1db198fa)]     at Pipe.onStreamRead (internal/stream_base_commons.js:166:17)
[HTTP] <-- POST /wd/hub/session/1db198fa-6984-4550-b09b-326ceb44357b/context 500 8

Result of the getContext method of a successful execution:

[HTTP] --> GET /wd/hub/session/156afb3b-5d7a-42dd-8472-09e6cce7d6a9/contexts
[HTTP] {}
[debug] [W3C (156afb3b)] Calling AppiumDriver.getContexts() with args: ["156afb3b-5d7a-42dd-8472-09e6cce7d6a9"]
[debug] [XCUITest] Executing command 'getContexts'
[debug] [iOS] Getting list of available contexts
[debug] [iOS] Retrieving contexts and views
[debug] [iOS] Selecting by url: false
[debug] [RemoteDebugger] Selecting application
[debug] [RemoteDebugger] Current applications available:
[debug] [RemoteDebugger]     Application: 'PID:58876'
[debug] [RemoteDebugger]         id: "PID:58876"
[debug] [RemoteDebugger]         isProxy: false
[debug] [RemoteDebugger]         name: "myApp"
[debug] [RemoteDebugger]         bundleId: "myAppBundleId"
[debug] [RemoteDebugger]         hostId: undefined
[debug] [RemoteDebugger]         isActive: 2
[debug] [RemoteDebugger]         isAutomationEnabled: false
[debug] [RemoteDebugger]         pageArray: []
[debug] [RemoteDebugger]     Application: 'PID:58899'
[debug] [RemoteDebugger]         id: "PID:58899"
[debug] [RemoteDebugger]         isProxy: true
[debug] [RemoteDebugger]         name: "com.apple.WebKit.WebContent"
[debug] [RemoteDebugger]         bundleId: "com.apple.WebKit.WebContent"
[debug] [RemoteDebugger]         hostId: "PID:58876"
[debug] [RemoteDebugger]         isActive: 1
[debug] [RemoteDebugger]         isAutomationEnabled: false
[debug] [RemoteDebugger]         pageArray:
[debug] [RemoteDebugger]           - id: 1
[debug] [RemoteDebugger]             title: "myTitle" <-- here the webview attributes are mapped to the Webcontent process
[debug] [RemoteDebugger]             url: "myUrl"
[debug] [RemoteDebugger]             isKey: false
[debug] [RemoteDebugger] Found app id key 'PID:58876' for bundle 'myAppBundleID'
[debug] [RemoteDebugger] Found separate bundleId 'com.apple.WebKit.WebContent' acting as proxy for 'myAppBundleID', with app id 'PID:58899'
[debug] [RemoteDebugger] Trying out the possible app ids: PID:58876, PID:58899
[debug] [RemoteDebugger] Selecting app PID:58876 (try #1 of 20)
[debug] [RemoteDebugger] Sending '_rpc_forwardGetListing:' message to remote debugger (id: 101)
[debug] [RemoteDebugger] Received response from socket send: '["PID:58876",{"1":{"WIRPageIdentifierKey":1,"WI...'
[debug] [RemoteDebugger] Received page change notice for app 'PID:58876' but the listing has not changed. Ignoring.
[debug] [RemoteDebugger] Received altered app id, updating from 'PID:58876' to 'PID:58899'
[debug] [RemoteDebugger] Finally selecting app PID:58899: [{"id":1,"title":"myTitle","url":"myUrl","isKey":false}]
[debug] [W3C (156afb3b)] Responding to client with driver.getContexts() result: ["NATIVE_APP","WEBVIEW_58899.1"] <-- here the returned webview maps the second process, i.e., the WebContent process
[HTTP] <-- GET /wd/hub/session/156afb3b-5d7a-42dd-8472-09e6cce7d6a9/contexts 200