Class chain query error on dollar sign

Issues/Bugs
1

Hi team, I am doing Class Chain query including expression for descendants, it fails on dollar sign. But according to Class Chain Queries Construction Rules the dollar $ sign is used to query descendants.

Appium Version: 1.7.1

The request:

{“using”:“class chain”,“value”:“**/XCUIElementTypeCell[`visible == 1`][$type == ‘XCUIElementTypeStaticText’ AND name == ‘From’$]/XCUIElementTypeTextField”}

The result:
{
“value”: “Cannot parse class chain query ‘**/XCUIElementTypeCell[`visible == 1`][$type == ‘XCUIElementTypeStaticText’ AND name == ‘From’$]/XCUIElementTypeTextField’.
Unexpected character detected at position 40:\n**/XCUIElementTypeCell[`visible == 1`][$ <----\n\n(\n\t0 CoreFoundation 0x000000010bb1b1ab __exceptionPreprocess + 171\n\t1 libobjc.A.dylib 0x000000010b1b0f41 objc_exception_throw + 48\n\t2 WebDriverAgentLib 0x0000000121c88938 -[XCUIElement(FBClassChain) fb_descendantsMatchingClassChain:shouldReturnAfterFirstMatch:] + 376\n\t3 WebDriverAgentLib 0x0000000121ca3341 +[FBFindElementCommands elementsUsing:withValue:under:shouldReturnAfterFirstMatch:] + 897\n\t4 WebDriverAgentLib 0x0000000121ca242c +[FBFindElementCommands handleFindElements:] + 300\n\t5 WebDriverAgentLib 0x0000000121c90053 -[FBRoute_TargetAction mountRequest:intoResponse:] + 179\n\t6 WebDriverAgentLib 0x0000000121c87794 __37-[FBWebServer registerRouteHandlers:]_block_invoke + 548\n\t7 RoutingHTTPServer 0x0000000121d33c18 -[RoutingHTTPServer handleRoute:withRequest:response:] + 136\n\t8 RoutingHTTPServer 0x0000000121d344fa __72-[RoutingHTTPServer routeMethod:withPath:parameters:request:connection:]_block_invoke + 47\n\t9 libdispatch.dylib 0x000000011039f2b5 _dispatch_client_callout + 8\n\t10 libdispatch.dylib 0x00000001103aa999 _dispatch_sync_thread_bound_invoke + 108\n\t11 libdispatch.dylib 0x000000011039f2b5 _dispatch_client_callout + 8\n\t12 libdispatch.dylib 0x00000001103a9496 _dispatch_main_queue_callback_4CF + 1260\n\t13 CoreFoundation 0x000000010baddee9 CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE + 9\n\t14 CoreFoundation 0x000000010baa2592 _CFRunLoopRun + 2402\n\t15 CoreFoundation 0x000000010baa19b9 CFRunLoopRunSpecific + 409\n\t16 Foundation 0x000000010abace5e -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 274\n\t17 WebDriverAgentLib 0x0000000121c8666a -[FBWebServer startServing] + 346\n\t18 WebDriverAgentRunner 0x0000000120e92fbe -[UITestingUITests testRunner] + 126\n\t19 CoreFoundation 0x000000010ba9f49c invoking + 140\n\t20 CoreFoundation 0x000000010ba9f370 -[NSInvocation invoke] + 320\n\t21 XCTest 0x000000010aa68125 __24-[XCTestCase invokeTest]_block_invoke + 591\n\t22 XCTest 0x000000010aab0a52 -[XCUITestContext performInScope:] + 183\n\t23 XCTest 0x000000010aa67ecb -[XCTestCase invokeTest] + 141\n\t24 XCTest 0x000000010aa68e8c __26-[XCTestCase performTest:]_block_invoke.369 + 42\n\t25 XCTest 0x000000010aab57f9 +[XCTContext runInContextForTestCase:block:] + 163\n\t26 XCTest 0x000000010aa68828 -[XCTestCase performTest:] + 608\n\t27 XCTest 0x000000010aa6482e __27-[XCTestSuite performTest:]_block_invoke + 363\n\t28 XCTest 0x000000010aa64195 -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26\n\t29 XCTest 0x000000010aa64392 -[XCTestSuite performTest:] + 239\n\t30 XCTest 0x000000010aa6482e __27-[XCTestSuite performTest:]_block_invoke + 363\n\t31 XCTest 0x000000010aa64195 -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26\n\t32 XCTest 0x000000010aa64392 -[XCTestSuite performTest:] + 239\n\t33 XCTest 0x000000010aa6482e __27-[XCTestSuite performTest:]_block_invoke + 363\n\t34 XCTest 0x000000010aa64195 -[XCTestSuite _performProtectedSectionForTest:testSection:] + 26\n\t35 XCTest 0x000000010aa64392 -[XCTestSuite performTest:] + 239\n\t36 XCTest 0x000000010aabcf23 __44-[XCTTestRunSession runTestsAndReturnError:]_block_invoke + 40\n\t37 XCTest 0x000000010aa77a0e -[XCTestObservationCenter _observeTestExecutionForBlock:] + 475\n\t38 XCTest 0x000000010aabcdc2 -[XCTTestRunSession runTestsAndReturnError:] + 281\n\t39 XCTest 0x000000010aa53e87 -[XCTestDriver runTestsAndReturnError:] + 314\n\t40 XCTest 0x000000010aab4a64 _XCTestMain + 619\n\t41 CoreFoundation 0x000000010babe18c CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK + 12\n\t42 CoreFoundation 0x000000010baa296b __CFRunLoopDoBlocks + 203\n\t43 CoreFoundation 0x000000010baa2144 __CFRunLoopRun + 1300\n\t44 CoreFoundation 0x000000010baa19b9 CFRunLoopRunSpecific + 409\n\t45 GraphicsServices 0x000000010ee189c6 GSEventRunModal + 62\n\t46 UIKit 0x000000010bf96948 UIApplicationMain + 159\n\t47 WebDriverAgentRunner-Runner 0x000000010a7ce838 WebDriverAgentRunner-Runner + 6200\n\t48 libdyld.dylib 0x0000000110413d81 start + 1\n\t49 ??? 0x0000000000000005 0x0 + 5\n)”,
“sessionId”: “32D1C9B2-5632-4DC5-881A-2DDE67614576”,
“status”: 13
}

Query expression:
**/XCUIElementTypeCell[`visible == 1`][$type == ‘XCUIElementTypeStaticText’ AND name == ‘From’$]/XCUIElementTypeTextField

2

From the link you provided:

Use `` or $$ to escape a single ` or $ character inside predicate expression.

Could you try that?

3

The request with $$ looks like this

{“using”:“class chain”,“value”:“**/XCUIElementTypeCell[`visible == 1`][$$type == ‘XCUIElementTypeStaticText’ AND name == ‘From’$$]/XCUIElementTypeTextField”}

Which response is

{
“value”: "Cannot parse class chain query ‘**/XCUIElementTypeCell[`visible == 1`][$$type == ‘XCUIElementTypeStaticText’ AND name == ‘From’$$]/XCUIElementTypeTextField’.
Unexpected character detected at position 40:\n**/XCUIElementTypeCell[`visible == 1`][$ <----\n\n(\n\t0 CoreFoundation 0x000000010bb1b1ab __exceptionPreprocess + 171\n\t1 …

4

When I read the example expressions from the link you provided, all of them use backticks on the visible property, such as:

[`visible == 1`]

But your expression does not seem to do that. Is it a problem with the formatting on this board, or did you leave that out (and can you add it if so?).

5

Yes, it was formatting issue on this page, all examples are having the " ` " for “visible” attribute expression (thank you @wreed for noticing that, all examples are corrected now to show backticks). My expressions are based on documentation example.

6

Never mind! It was published with [email protected] within the WDA#707 commit. Mine was older.

7

@Murdoc how did you solve this problem?
I also get the error message that the dollar sign could not be parsed. I also tried to escape the dollar sign with backslashes but i didn’t work.

Edit: An update of the appium server from 1.7.1 to the newest version (1.8.1-beta3) worked for me