VS Code Javac & JUnit tasks.json

tasks.json

/*
    Example for quick Java compilation and unit tests in VS Code.
    Works well with simple BlueJ projects.
    Hit Ctrl+Shift+B to compile currently open file with javac.
    Hit Ctrl+Shift+T to test currently open test class.
    See red wiggles for compilation errors / failed assertions or click exclamation mark in the status bar.
    Uses a few workarounds for individual commands per task and filename without extension.
    This is written for Windows but it should be easy to adopt for Linux and Mac.
*/
{
    "version": "0.1.0",
    "isShellCommand": true,
    "suppressTaskName": true,
    "showOutput": "silent",
    "windows": {
        "command": "powershell",
        "args": ["-Command"],
        "tasks": [
            {
                // tests the currently open test class. java has to be in %PATH% and the jUnit-jar in %CLASSPATH%.
                "taskName": "junit",
                "args": ["$env:CLASSPATH += ';${fileDirname}'; $class = [System.IO.Path]::GetFileNameWithoutExtension('${fileBasename}'); java org.junit.runner.JUnitCore $class | Select-String -NotMatch -Pattern 'at (?!.+${fileBasename})'"],
                "isTestCommand": true,
                "problemMatcher": {
                    "owner": "java",
                    "fileLocation": ["relative", "${fileDirname}"],
                    "pattern": [
                        {
                            "regexp": "^(.*)$",
                            "message": 1
                        },
                        {
                            "regexp": "^\\s*at .+\\((.+):([0-9]+)\\)$",
                            "file": 1,
                            "line": 2
                        }
                    ]
                }
            },
            {
                // compiles the currently open file. javac has to be in %PATH%
                "taskName": "javac",
                "args": ["$env:CLASSPATH += ';${fileDirname}'; javac ${file} -Xlint"],
                "isBuildCommand": true,
                "problemMatcher": {
                    "owner": "java",
                    "fileLocation": "absolute",
                    "pattern": {
                        "regexp": "^(.*):([0-9]+): (error|warning): (.*)$",
                        "file": 1,
                        "line": 2,
                        "severity": 3,
                        "message": 4
                    }
                }
            },
            {
                // compiles all files in the folder of the currently opened file
                "taskName": "javac all",
                "args": ["$env:CLASSPATH += ';${fileDirname}'; javac ${fileDirname}\\*.java -Xlint"],
                "showOutput": "silent",
                "problemMatcher": {
                    "owner": "java",
                    "fileLocation": "absolute",
                    "pattern": {
                        "regexp": "^(.*):([0-9]+): (error|warning): (.*)$",
                        "file": 1,
                        "line": 2,
                        "severity": 3,
                        "message": 4
                    }
                }
            }
        ]
    }
}