How to debug dotnet test in VS Code?

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.