`System.NullReferenceException: Object reference not set to an instance of an object.` error with Combo Box

[m-saikiran]

• [x] Please attach the test suite YAML & .msapp which demonstrates the issue you are experiencing and any logs written to the specified outputDirectory. (Please do not attach any file which may contain sensitive personal or company data.)

App: SampleAppforTestEngine_20221026141239.zip

Test Suite:

testSuite:
  testSuiteName: SampleTestSuite
  testSuiteDescription: Verify the functionality of ComboBox in Canvas App
  persona: User1
  appLogicalName: <REDACTED>

  testCases:
    - testCaseName: NavigateToSecondScreen
      testSteps: |
        = Select('Button1');
          SetProperty('ComboBox1'.SelectedItems, Table({'Name':"Record 1"}));          
testSettings:
  recordVideo: true
  browserConfigurations:
    - browser: Chromium

environmentVariables:
  users:
    - personaName: User1
      emailKey: user1Email
      passwordKey: user1Password

Describe the bug

Test Engine throws System.NullReferenceException: Object reference not set to an instance of an object. error when setting a value to Combo box control in Power Apps Canvas App. Here, SetProperty() function is used to set the value.

To Reproduce

Steps to reproduce the behavior:

1. Insert a Combo Box control in Power Apps Canvas App.
2. Use a Dataverse table or a collection as a datasource for the above created Combo Box control. The column name of the table should be anything other than Value.
3. Write a test case that sets the value of Combo Box as below:

   SetProperty('ComboBox1'.SelectedItems, Table({'Name':"Sample App"}));

Expected Behavior:

Test Engine should set the value of Combo Box as defined in the SetProperty() function.

Actual Behavior:

The test has failed with the below errors:

PS /<REDACTED>/PowerApps-TestEngine/src/PowerAppsTestEngine> dotnet run
Test results will be stored in: TestOutput/2fed15

---------------------------------------------------------------------------
RUNNING TEST SUITE: SampleTestSuite
---------------------------------------------------------------------------

Browser configuration: {"Browser":"Chromium","Device":null,"ScreenWidth":null,"ScreenHeight":null,"ConfigName":null}

Browser setup finished

Browser context created

Test infrastructure setup finished

Successfully navigate page to target URL.

---------------------------------------------------------------------------
RUNNING TEST CASE: NavigateToSecondScreen
---------------------------------------------------------------------------

[Warning]: Syntax check failed. Now attempting to execute lines step by step

------------------------------

Executing SetProperty function.

[Error]: System.AggregateException: One or more errors occurred. (Exception has been thrown by the target of an invocation.)
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.AggregateException: One or more errors occurred. (Object reference not set to an instance of an object.)
 ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.PowerApps.TestEngine.PowerApps.PowerAppFunctions.SetPropertyTableAsync(ItemPath itemPath, TableValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerApps/PowerAppFunctions.cs:line 239
   at Microsoft.PowerApps.TestEngine.PowerApps.PowerAppFunctions.SetPropertyAsync(ItemPath itemPath, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerApps/PowerAppFunctions.cs:line 186
   at Microsoft.PowerApps.TestEngine.PowerFx.Functions.SetPropertyFunction.SetProperty(RecordValue obj, StringValue propName, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/Functions/SetPropertyFunction.cs:line 44
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.Wait()
   at Microsoft.PowerApps.TestEngine.PowerFx.Functions.SetPropertyFunction.Execute(RecordValue obj, StringValue propName, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/Functions/SetPropertyFunction.cs:line 32
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Span`1& arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.PowerFx.ReflectionFunction.Invoke(FormulaValue[] args)
   at Microsoft.PowerFx.ReflectionFunction.<GetTexlFunction>b__7_0(FormulaValue[] args)
   at Microsoft.PowerFx.CustomSetPropertyFunction.InvokeAsync(FormulaValue[] args, CancellationToken cancellation)
   at Microsoft.PowerFx.EvalVisitor.TryHandleSetProperty(CallNode node, EvalVisitorContext context)
   at Microsoft.PowerFx.EvalVisitor.Visit(CallNode node, EvalVisitorContext context)
   at Microsoft.PowerFx.ParsedExpression.EvalAsync(RecordValue parameters, CancellationToken cancel)
   at Microsoft.PowerFx.RecalcEngine.EvalAsync(String expressionText, CancellationToken cancel, RecordValue parameters, ParserOptions options)
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1.get_Result()
   at Microsoft.PowerFx.RecalcEngine.Eval(String expressionText, RecordValue parameters, ParserOptions options)
   at Microsoft.PowerApps.TestEngine.PowerFx.PowerFxEngine.Execute(String testSteps) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/PowerFxEngine.cs:line 123
   at Microsoft.PowerApps.TestEngine.PowerFx.PowerFxEngine.ExecuteWithRetryAsync(String testSteps) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/PowerFxEngine.cs:line 70
   at Microsoft.PowerApps.TestEngine.SingleTestRunner.RunTestAsync(String testRunId, String testRunDirectory, TestSuiteDefinition testSuiteDefinition, BrowserConfiguration browserConfig, String queryParams) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/SingleTestRunner.cs:line 142

---------------------------------------------------------------------------
SampleTestSuite TEST SUMMARY
---------------------------------------------------------------------------

Total cases: 1

Cases passed: 0

Cases skipped: 0

Cases failed: 1

Test results can be found here: TestOutput/2fed15/Results_2fed15dd-f34b-4247-9fe5-7f71a62c55d6.trx

Additional context

I believe that the source code is expecting the column name of table to be Value. The tests ran successfully when we made the below changes:

1. Updated the column name in the table to Value
2. Updated the SetProperty as follows SetProperty('ComboBox1'.SelectedItems, Table({'Value':"Record 1"}));

Additionally, if the column name is set to Value in SetProperty() function, without changing it in the Datasource (Dataverse), below error is thrown:

[Error]: System.AggregateException: One or more errors occurred. (Exception has been thrown by the target of an invocation.)
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.AggregateException: One or more errors occurred. (Error: Contract failure: Unspecified.
    at Z (https://content.powerapps.com/resource/app/5ov1l0job96ha/publish/js/pa.core.bundle3.js:62:78486)
    at Object.u [as checkValue] (https://content.powerapps.com/resource/app/5ov1l0job96ha/publish/js/pa.core.bundle3.js:62:76240)
    at ControlWidget.interactWithControlAsync (https://content.powerapps.com/resource/app/2lc91ftsgjsce/publish/js/pa.common.bundle1.js:4:146461)
    at interactWithControl (/<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/JS/PublishedAppTesting.js:186:146)
    at eval (eval at onMessage (https://pa-static-ms.azureedge.net/resource/webplayerdynamic/publishedapp/preloadindex?preloadIndexPath=https%3A%2F%2Fcontent.powerapps.com%2Fresource%2Fapp%2Fmu7r2b8lrlh44%2Fpreloadindex.web.html&PowerAppsLanguage=en-US&loader=inline&lv=d5r9l51q3u44d&serviceWorkerUrl=https%3A%2F%2Fpa-static-ms.azureedge.net%2Fresource%2Fwebplayer%2Fhashedresources%2Fp681v2nkcinh5%2Fjs%2FPowerAppsServiceWorker.PublishedApp.js&unregisterServiceWorkersHash=61al1u62ufj72&piv=48DEC944&featureGates={%22publishedAppServiceWorker%22:false}:1:10728), <anonymous>:3:26)
    at onMessage (https://pa-static-ms.azureedge.net/resource/webplayerdynamic/publishedapp/preloadindex?preloadIndexPath=https%3A%2F%2Fcontent.powerapps.com%2Fresource%2Fapp%2Fmu7r2b8lrlh44%2Fpreloadindex.web.html&PowerAppsLanguage=en-US&loader=inline&lv=d5r9l51q3u44d&serviceWorkerUrl=https%3A%2F%2Fpa-static-ms.azureedge.net%2Fresource%2Fwebplayer%2Fhashedresources%2Fp681v2nkcinh5%2Fjs%2FPowerAppsServiceWorker.PublishedApp.js&unregisterServiceWorkersHash=61al1u62ufj72&piv=48DEC944&featureGates={%22publishedAppServiceWorker%22:false}:255:10759))
 ---> Microsoft.Playwright.PlaywrightException: Error: Contract failure: Unspecified.
    at Z (https://content.powerapps.com/resource/app/5ov1l0job96ha/publish/js/pa.core.bundle3.js:62:78486)
    at Object.u [as checkValue] (https://content.powerapps.com/resource/app/5ov1l0job96ha/publish/js/pa.core.bundle3.js:62:76240)
    at ControlWidget.interactWithControlAsync (https://content.powerapps.com/resource/app/2lc91ftsgjsce/publish/js/pa.common.bundle1.js:4:146461)
    at interactWithControl (/<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/JS/PublishedAppTesting.js:186:146)
    at eval (eval at onMessage (https://pa-static-ms.azureedge.net/resource/webplayerdynamic/publishedapp/preloadindex?preloadIndexPath=https%3A%2F%2Fcontent.powerapps.com%2Fresource%2Fapp%2Fmu7r2b8lrlh44%2Fpreloadindex.web.html&PowerAppsLanguage=en-US&loader=inline&lv=d5r9l51q3u44d&serviceWorkerUrl=https%3A%2F%2Fpa-static-ms.azureedge.net%2Fresource%2Fwebplayer%2Fhashedresources%2Fp681v2nkcinh5%2Fjs%2FPowerAppsServiceWorker.PublishedApp.js&unregisterServiceWorkersHash=61al1u62ufj72&piv=48DEC944&featureGates={%22publishedAppServiceWorker%22:false}:1:10728), <anonymous>:3:26)
    at onMessage (https://pa-static-ms.azureedge.net/resource/webplayerdynamic/publishedapp/preloadindex?preloadIndexPath=https%3A%2F%2Fcontent.powerapps.com%2Fresource%2Fapp%2Fmu7r2b8lrlh44%2Fpreloadindex.web.html&PowerAppsLanguage=en-US&loader=inline&lv=d5r9l51q3u44d&serviceWorkerUrl=https%3A%2F%2Fpa-static-ms.azureedge.net%2Fresource%2Fwebplayer%2Fhashedresources%2Fp681v2nkcinh5%2Fjs%2FPowerAppsServiceWorker.PublishedApp.js&unregisterServiceWorkersHash=61al1u62ufj72&piv=48DEC944&featureGates={%22publishedAppServiceWorker%22:false}:255:10759)
   at Microsoft.Playwright.Transport.Connection.InnerSendMessageToServerAsync[T](String guid, String method, Object args) in /_/src/Playwright/Transport/Connection.cs:line 164
   at Microsoft.Playwright.Transport.Connection.WrapApiCallAsync[T](Func`1 action, Boolean isInternal) in /_/src/Playwright/Transport/Connection.cs:line 479
   at Microsoft.Playwright.Core.Frame.EvaluateAsync[T](String script, Object arg) in /_/src/Playwright/Core/Frame.cs:line 496
   at Microsoft.PowerApps.TestEngine.TestInfra.PlaywrightTestInfraFunctions.RunJavascriptAsync[T](String jsExpression) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/TestInfra/PlaywrightTestInfraFunctions.cs:line 278
   at Microsoft.PowerApps.TestEngine.PowerApps.PowerAppFunctions.SetPropertyTableAsync(ItemPath itemPath, TableValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerApps/PowerAppFunctions.cs:line 249
   at Microsoft.PowerApps.TestEngine.PowerApps.PowerAppFunctions.SetPropertyAsync(ItemPath itemPath, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerApps/PowerAppFunctions.cs:line 186
   at Microsoft.PowerApps.TestEngine.PowerFx.Functions.SetPropertyFunction.SetProperty(RecordValue obj, StringValue propName, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/Functions/SetPropertyFunction.cs:line 44
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.Wait()
   at Microsoft.PowerApps.TestEngine.PowerFx.Functions.SetPropertyFunction.Execute(RecordValue obj, StringValue propName, FormulaValue value) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/Functions/SetPropertyFunction.cs:line 32
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Span`1& arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.PowerFx.ReflectionFunction.Invoke(FormulaValue[] args)
   at Microsoft.PowerFx.ReflectionFunction.<GetTexlFunction>b__7_0(FormulaValue[] args)
   at Microsoft.PowerFx.CustomSetPropertyFunction.InvokeAsync(FormulaValue[] args, CancellationToken cancellation)
   at Microsoft.PowerFx.EvalVisitor.TryHandleSetProperty(CallNode node, EvalVisitorContext context)
   at Microsoft.PowerFx.EvalVisitor.Visit(CallNode node, EvalVisitorContext context)
   at Microsoft.PowerFx.ParsedExpression.EvalAsync(RecordValue parameters, CancellationToken cancel)
   at Microsoft.PowerFx.RecalcEngine.EvalAsync(String expressionText, CancellationToken cancel, RecordValue parameters, ParserOptions options)
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1.get_Result()
   at Microsoft.PowerFx.RecalcEngine.Eval(String expressionText, RecordValue parameters, ParserOptions options)
   at Microsoft.PowerApps.TestEngine.PowerFx.PowerFxEngine.Execute(String testSteps) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/PowerFxEngine.cs:line 130
   at Microsoft.PowerApps.TestEngine.PowerFx.PowerFxEngine.ExecuteWithRetryAsync(String testSteps) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/PowerFx/PowerFxEngine.cs:line 70
   at Microsoft.PowerApps.TestEngine.SingleTestRunner.RunTestAsync(String testRunId, String testRunDirectory, TestSuiteDefinition testSuiteDefinition, BrowserConfiguration browserConfig, String queryParams) in /<REDACTED>/PowerApps-TestEngine/src/Microsoft.PowerApps.TestEngine/SingleTestRunner.cs:line 142

Note: These test cases work fine without any issues in Test Studio.

Due to this issue, I couldn't proceed further on testing.

[clairewu0218]

Hi,

Could you send us the app file again? Not sure why I cannot download the attached app.

Thanks, Claire

[m-saikiran]

Hi @clairewu0218,

Here is the app file: SampleAppforTestEngine_20221026141239.zip

Let me know if you still can't download it.

[clairewu0218]

Hi @m-saikiran,

I modified the syntax to be SetProperty('ComboBox1'.SelectedItems, Table({Value:"Record 1"})); and it worked on my end. Feel free to let me know if it doesn't work for you.

Now test engine throws error if a Table input is not in the format of Table({Value:"some value"}), which is a bug. I'm working on fixing it and thanks for your help in identifying this.

[clairewu0218]

Hi @m-saikiran,

The bug was fixed. Feel free to let us know if you have further questions. Thanks!