How to debug dotnet test in VS Code? - unit-testing

Question

This article describes setting the VS Code settings to point the debugging target at the build output of the unit test project. I have therefore set mine like this:
{
"explorer.confirmDragAndDrop": false,
"git.allowForcePush": true,
"git.autofetch": true,
"window.zoomLevel": 0,
"csharp.unitTestDebuggingOptions": {
"sourceFileMap": {
"C:\\git\\MsTester\\bin\\Debug\\netcoreapp2.1": "C:\\git\\MsTester\\bin\\Debug\\netcoreapp2.1"
}
},
"files.autoSave": "afterDelay",
"files.exclude": {
"**/bin": true,
"**/node_modules": true,
"**/obj": true
},
"csharpfixformat.style.spaces.insideEmptyBraces": false,
"csharpfixformat.style.braces.allowInlines": false,
"csharpfixformat.style.spaces.beforeParenthesis": false,
"csharpfixformat.style.spaces.afterParenthesis": false,
"csharp.format.enable": false,
"extensions.ignoreRecommendations": true
}
However, I am not sure how to setup the launch.json to kick off the dotnet test so that it can attach the debugger.
This is what I've got currently:
{
"version": "0.2.0",
"configurations": [
{
"name": "MsTester",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build",
"program": "${workspaceFolder}/MsTester/bin/Debug/netcoreapp2.1/MsTester.dll",
"windows": {
"args": [
"--filter",
"TestCategory=lbshell",
"--logger",
"trx",
"--results-directory",
".\\TestResults",
"--settings",
".\\Features\\runsettings.xml"
],
},
"cwd": "${workspaceFolder}/MsTester",
"console": "internalConsole",
"stopAtEntry": false,
"internalConsoleOptions": "openOnSessionStart"
},
]
}
Is there an option to tell VS Code that it needs to execute dotnet test instead of dotnet run?
I was hoping this page would indicate how to do that, but it does not.

Answer 1

All credit is due to #Lance U. Matthews as he posted this as a comment to an answer to the question: How does one debug an MSTest in VSCode? . I am reposting this as a proper answer because he hasn't done so in a year.
The following answer has been tested on VSCode v1.62.3 and dotnet tools v5.0.403.
Assuming you have a .NET solution with a structure like this:
mysolution.sln
tests\
|---> tests.csproj
|---> UnitTest1.cs
.vscode\
|---> launch.json
|---> tasks.json
Copy the following into the tasks.json file:
{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"label": ".NET Core Test with debugger",
"type": "process",
"isBackground": true,
"command": "dotnet",
"args": [ "test" ],
"options":
{
"cwd": "${workspaceFolder}/tests",
"env":
{
"VSTEST_HOST_DEBUG": "1"
},
},
"group": "test", "presentation":
{
"echo": true,
"reveal": "always",
"focus": false,
"panel": "shared"
},
"problemMatcher": []
},
]
}
And this into the launch.json file:
{
"version": "0.2.0",
"configurations": [
{
"name": ".NET Core Attach",
"type": "coreclr",
"request": "attach"
}
]
}
Now set a breakpoint anywhere in your UnitTest1.cs file and run .NET Core Test with debugger task (Terminal->Run task...).
The Test Execution Command Line Tool should launch and at the bottom of your terminal should be something like:
Your Process Id will certainly be different but that is expected behavior.
Now you need to switch to "Run and Debug" tab (ctrl+shift+d) and select ".NET Core Attach" (it should be in the upper left part of the VSCode).
Provide the process id that appeared previously in the terminal:
Now click F5 once and you should reach one of your breakpoints.

Answer 2

This may not answer solve your problem of passing the arguments entirely, but may solve the problem of passing runsettings parameters to the code being debugged. Using this method, I was able to pass the contents of runsettings to my code when running the debugger (i.e. when I click "Debug Test" above the method):
What I ended up doing is this:
First, I wrote a bit of code that will read from the settings file (via TestContext) OR from the user environment if the key was not available in the settings file, i.e.:
[ClassInitialize]
public static void TestClassInitialize(TestContext context)
{
v = Settings.GetSettingValueFromContextOrEnvironment("v", context);
}
Here is the implementation of GetSettingValueFromContextOrEnvironment:
/// <summary>
/// Attempts to read a setting value from the context (populated through runsettings). If the
/// key is not present in the context, the value will be read from the user environment variable
/// instead.
///
/// This allows running the unit test code in VSCode debugger that currently doesn't seem to allow
/// passing runsettings file to the DLL.
/// </summary>
/// <param name="name"></param>
/// <param name="context"></param>
/// <returns></returns>
public static String GetSettingValueFromContextOrEnvironment(string name, TestContext context){
if (context.Properties.ContainsKey(name)){
return context.Properties[name].ToString();
} else {
String envVar = Environment.GetEnvironmentVariable(name, System.EnvironmentVariableTarget.User);
if (envVar == null){
throw new Exception(String.Format("Environment variable '{0}' was not available neither in the context file nor in the environment.", name));
} else {
return envVar;
}
}
}
I then wrote a Powershell that will read my settings file to parse parameters and set them as user environment variables, like this:
<# This script updates user environment variables with parameters stored in *.runsettings file that is provided to it as the only argument on the command line.
Example usage:
.\set_settings_env.ps1 local.runsettings
#>
param (
[Parameter(Mandatory=$true)][string]$settings_file
)
[xml]$xml = Get-Content $settings_file
foreach( $parameter in $xml.RunSettings.TestRunParameters.Parameter)
{
write-host("Setting environment variable: " + $parameter.name)
[Environment]::SetEnvironmentVariable($parameter.name, $parameter.value, "User")
}
So now I am able to both run the code from command line with a specific runsettings file and debug by running the script to set my environment variables.

Answer 3

Perhaps this is more what you are looking for:
How does one debug an MSTest in VSCode?
(also check the comment).
So by using "VSTEST_HOST_DEBUG": "1" you should be able to attach a debug process, similar to how one can do it in Java.