feat(dotnet11): add process-api-net11 skill for new process APIs

plugins/dotnet11/README.md

@@ -4,4 +4,5 @@ Skills focused on new APIs and language features introduced in .NET 11.
 
 ## Skills
 
+- process-api-net11
 - system-text-json-net11

plugins/dotnet11/skills/process-api-net11/SKILL.md

@@ -0,0 +1,215 @@
+---
+name: process-api-net11
+description: >
+  Provides guidance on the new System.Diagnostics.Process APIs introduced in .NET 11.
+  It covers high-level convenience methods (Process.Run, Process.RunAndCaptureText, Process.StartAndForget),
+  reliable deadlock-free output reading (Process.ReadAllText/Bytes/Lines), and lifecycle/handle management
+  (KillOnParentExit, InheritedHandles, StartDetached).
+  Use when starting, orchestrating, or capturing output from external processes in .NET 11 applications.
+license: MIT
+---
+
+# Process API Improvements — .NET 11
+
+New APIs added to `System.Diagnostics.Process` in .NET 11 simplify process management, eliminate boilerplate, and prevent common deadlock patterns when capturing output.
+
+## When to Use
+
+- Running or orchestrating external processes in a .NET 11 (or later) project.
+- Needing to start a process, wait for it to exit, and capture its output/error streams without risking deadlocks (`Process.RunAndCaptureText[Async]`).
+- Wanting to ensure child processes are automatically terminated when the parent process exits (`KillOnParentExit`).
+- Requiring lightweight, low-overhead process creation via `SafeProcessHandle` for better performance characteristics across all form-factors and runtimes.
+- Requiring fine-grained control over handle inheritance (`InheritedHandles`) or starting detached processes (`StartDetached`).
+
+## When Not to Use
+
+- The project targets .NET 10 or earlier — these APIs are not available before .NET 11.
+- The default `Process.Start()` is sufficient and does not require output capturing or advanced lifecycle rules.
+
+## Target Framework
+
+```xml
+<TargetFramework>net11.0</TargetFramework>
+```
+
+## New APIs
+
+### Types
+
+Before using the new convenience methods, note the following return and record structures:
+
+- **`ProcessExitStatus`**: Represents the outcome of a completed process.
+  ```csharp
+  public readonly record struct ProcessExitStatus(int ExitCode)
+  {
+      public bool Success => ExitCode == 0;
+  }
+  ```
+- **`ProcessTextOutput`**: Contains the exit status along with all captured standard output and standard error text.
+  ```csharp
+  public readonly record struct ProcessTextOutput(ProcessExitStatus ExitStatus, string StandardOutput, string StandardError);
+  ```
+- **`ProcessOutputLine`**: Represents a single output line tagged with its stream source.
+  ```csharp
+  public readonly struct ProcessOutputLine
+  {
+      public string Content { get; }
+      public bool StandardError { get; }
+  }
+  ```
+
+### High-Level Convenience APIs
+
+#### Static Methods
+
+##### `Process.Run` / `Process.RunAsync`
+Starts a process and waits for it to exit, returning the exit status. Does not capture standard output or error. Passing `silent: true` discards standard output and error by internally redirecting standard handles to the `NUL` device.
+```csharp
+public static ProcessExitStatus Run(string fileName, IEnumerable<string>? arguments = null, bool silent = false, TimeSpan? timeout = null)
+public static Task<ProcessExitStatus> RunAsync(string fileName, IEnumerable<string>? arguments = null, bool silent = false, CancellationToken cancellationToken = default)
+public static ProcessExitStatus Run(ProcessStartInfo startInfo, TimeSpan? timeout = null)
+public static Task<ProcessExitStatus> RunAsync(ProcessStartInfo startInfo, CancellationToken cancellationToken = default)
+```
+
+##### `Process.RunAndCaptureText` / `Process.RunAndCaptureTextAsync`
+Starts a process, captures both standard output and error, and waits for it to exit. Extremely useful for avoiding deadlocks on stream redirection.
+```csharp
+public static ProcessTextOutput RunAndCaptureText(string fileName, IEnumerable<string>? arguments = null, TimeSpan? timeout = null)
+public static Task<ProcessTextOutput> RunAndCaptureTextAsync(string fileName, IEnumerable<string>? arguments = null, CancellationToken cancellationToken = default)
+public static ProcessTextOutput RunAndCaptureText(ProcessStartInfo startInfo, TimeSpan? timeout = null)
+public static Task<ProcessTextOutput> RunAndCaptureTextAsync(ProcessStartInfo startInfo, CancellationToken cancellationToken = default)
+```
+
+##### `Process.StartAndForget`
+There is a common misconception that when a process is disposed, it's also being killed. This is not the case, as `Process.Dispose` only releases the resources associated with the process, but does not kill it.
+
+To make it easier to start a process without the need to worry about disposing it, `Process.StartAndForget` was introduced. The method starts a process, returns its ID, and immediately releases all handle resources associated with it.
+```csharp
+public static int StartAndForget(string fileName, IEnumerable<string>? arguments = null)
+public static int StartAndForget(ProcessStartInfo startInfo)
+```
+
+#### Instance Methods
+These methods are called on a `Process` instance to directly read stdout and stderr, guaranteeing no OS pipe buffer overflow deadlocks.
+
+```csharp
+public (string StandardOutput, string StandardError) ReadAllText(TimeSpan? timeout = null)
+public Task<(string StandardOutput, string StandardError)> ReadAllTextAsync(CancellationToken cancellationToken = default)
+public (byte[] StandardOutput, byte[] StandardError) ReadAllBytes(TimeSpan? timeout = null)
+public Task<(byte[] StandardOutput, byte[] StandardError)> ReadAllBytesAsync(CancellationToken cancellationToken = default)
+public IEnumerable<ProcessOutputLine> ReadAllLines(TimeSpan? timeout = null)
+public IAsyncEnumerable<ProcessOutputLine> ReadAllLinesAsync(CancellationToken cancellationToken = default)
+```
+
+### ProcessStartInfo Properties
+
+#### `KillOnParentExit`
+Ensures that the spawned child process is terminated when the current (parent) process exits. Works across Windows, Linux, and Android.
+```csharp
+public bool KillOnParentExit { get; set; }
+```
+
+#### `InheritedHandles`
+Provides precise control over which file/kernel handles are inherited by the child process, preventing accidental resource leaks.
+- Standard handles (`stdin`, `stdout`, `stderr`) are always included (no need to add them to the list).
+- Setting the list to an empty list means only standard handles get inherited.
+- Only `SafeFileHandle` and `SafePipeHandle` instances are allowed as of today.
+- No global lock is used when spawning new processes on Windows (important for tuning projects that spawn multiple processes in parallel).
+```csharp
+public IList<SafeHandle>? InheritedHandles { get; set; }
+```
+
+#### `Silent`
+When set to `true`, the standard handles are by default redirected to the `NUL` device, ensuring the child process does not keep parent console or terminal resources alive.
+```csharp
+public bool Silent { get; set; }
+```
+
+#### `StartDetached`
+Starts the process detached from the parent's terminal or job session, ensuring it survives the parent's exit.
+```csharp
+public bool StartDetached { get; set; }
+```
+
+---
+
+## Examples
+
+### 1. One-Line Run and Capture Output
+
+Run a process and safely read all output text without stream deadlock risks. For simple CLI operations that don't need cancellation or async scalability, prefer the synchronous overload:
+
+```csharp
+using System;
+using System.Diagnostics;
+
+// Run 'git status' and capture output
+ProcessTextOutput result = Process.RunAndCaptureText("git", ["status"]);
+
+if (result.ExitStatus.ExitCode == 0)
+{
+    Console.WriteLine($"Git Output: {result.StandardOutput}");
+}
+else
+{
+    Console.WriteLine($"Failed with exit code: {result.ExitStatus.ExitCode}");
+    Console.WriteLine($"Error: {result.StandardError}");
+}
+```
+
+### 2. Auto-Killing Child Processes on Parent Exit
+
+Ensure a long-running background worker process is killed when the main application terminates:
+
+```csharp
+using System;
+using System.Diagnostics;
+
+ProcessStartInfo startInfo = new("dotnet", ["run", "--project", "BackgroundWorker.csproj"])
+{
+    KillOnParentExit = OperatingSystem.IsWindows() || OperatingSystem.IsLinux() // Auto-teardown when this parent process exits
+};
+
+using Process? process = Process.Start(startInfo);
+// The background worker is now tied to this process's lifecycle
+```
+
+### 3. Read All Lines From Output
+
+Start a process and read its output lines safely:
+
+```csharp
+using System;
+using System.Diagnostics;
+using System.Threading.Tasks;
+
+ProcessStartInfo startInfo = new("ping", ["127.0.0.1"])
+{
+    RedirectStandardOutput = true,
+    RedirectStandardError = true
+};
+
+using Process? process = Process.Start(startInfo);
+if (process != null)
+{
+    // Read all output lines safely and asynchronously
+    await foreach (ProcessOutputLine line in process.ReadAllLinesAsync())
+    {
+        string prefix = line.StandardError ? "[Err]" : "[Out]";
+        Console.WriteLine($"{prefix} > {line.Content}");
+    }
+}
+```
+
+### 4. Start and Forget (Fire & Forget)
+
+Launch a helper tool or browser without holding onto system handle structures:
+
+```csharp
+using System;
+using System.Diagnostics;
+
+// Fire and forget, getting back only the process ID
+int pid = Process.StartAndForget("notepad.exe");
+Console.WriteLine($"Notepad started with PID: {pid}");
+```

tests/dotnet11/process-api-net11/eval.yaml

@@ -0,0 +1,140 @@
+scenarios:
+  # --- Scenario 1: Run and capture output in .NET 11 ---
+  - name: "Run and capture process output in .NET 11"
+    prompt: |
+      I'm writing a .NET 11 command-line tool that needs to run an external CLI (e.g. 'git status') and capture both stdout and stderr.
+      I want to make sure I don't run into any OS pipe deadlock issues, and I want to write it in the cleanest way possible using new .NET 11 features.
+      Show me the C# program and the `.csproj` XML targeting `net11.0` for this tool. Print both in your response.
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "Process\\.RunAndCaptureText(Async)?"
+      - type: "output_matches"
+        pattern: "net11\\.0"
+      # The prompt asks for BOTH stdout AND stderr — require both members.
+      - type: "output_matches"
+        pattern: "\\.StandardOutput\\b"
+      - type: "output_matches"
+        pattern: "\\.StandardError\\b"
+      - type: "output_not_matches"
+        pattern: "RedirectStandardOutput\\s*=\\s*true"
+      - type: "output_not_matches"
+        pattern: "BeginOutputReadLine|OutputDataReceived"
+    rubric:
+      - "Uses the new built-in Process.RunAndCaptureText or Process.RunAndCaptureTextAsync static method"
+      - "Targets net11.0 in the project file"
+      - "Avoids manual redirection setup boilerplate (like RedirectStandardOutput = true, BeginOutputReadLine, etc.)"
+    timeout: 180
+
+  # --- Scenario 2: Auto-teardown child processes on parent exit ---
+  - name: "Auto-teardown child processes on parent exit in .NET 11"
+    prompt: |
+      In a .NET 11 application, I need to spawn a background daemon process.
+      To prevent orphan processes, I want to ensure that this daemon process is automatically killed by the operating system if my main parent process crashes or exits.
+      How do I configure this in .NET 11 using ProcessStartInfo? Show me a minimal example, and show the `.csproj` XML targeting `net11.0` in your response.
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "KillOnParentExit\\s*=\\s*true"
+      - type: "output_matches"
+        pattern: "net11\\.0"
+    rubric:
+      - "Uses the new KillOnParentExit property on ProcessStartInfo set to true"
+      - "Targets net11.0"
+    timeout: 180
+
+  # --- Scenario 3: deadlock-free full read via instance ReadAllText (tuple return) ---
+  - name: "Deadlock-free full-output read via instance ReadAllText in .NET 11"
+    prompt: |
+      In a .NET 11 app I start a child process myself with `Process.Start(...)` because I
+      need to configure `ProcessStartInfo` first. After it starts I want to read its ENTIRE
+      standard output AND standard error to completion, without the classic deadlock where
+      one buffer fills while I'm draining the other. Give me the simplest first-party .NET 11
+      way to get both back at once. Show a minimal program and the `net11.0` `.csproj`.
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "net11\\.0"
+      - type: "output_matches"
+        pattern: "ReadAllText(Async)?\\s*\\("
+      # Correct: destructure the (StandardOutput, StandardError) tuple (sync or async form).
+      - type: "output_matches"
+        pattern: "\\)\\s*=\\s*(await\\s+)?\\w+\\.ReadAllText(Async)?\\s*\\("
+      # Wrong: assigning the tuple-returning call to a single string.
+      - type: "output_not_matches"
+        pattern: "string\\s+\\w+\\s*=\\s*(await\\s+)?\\w+\\.ReadAllText(Async)?\\s*\\("
+    rubric:
+      - "Uses the new instance method Process.ReadAllText/ReadAllTextAsync"
+      - "Destructures the (string StandardOutput, string StandardError) tuple — not a single string"
+      - "Does not fall back to manual StandardOutput.ReadToEndAsync() as the primary mechanism"
+      - "Targets net11.0"
+    timeout: 180
+
+  # --- Scenario 4: stream tagged output lines via ReadAllLinesAsync ---
+  - name: "Stream tagged process output lines in .NET 11"
+    prompt: |
+      I have a long-running child process in a .NET 11 app. As it runs I want to handle each
+      output line the moment it is produced — not buffer everything to the end — and for each
+      line I need to know whether it came from stdout or stderr. I want the cleanest first-party
+      .NET 11 approach, with no event-callback plumbing and no deadlock risk. Show a minimal
+      program and the `net11.0` `.csproj`.
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "net11\\.0"
+      - type: "output_matches"
+        pattern: "ReadAllLines(Async)?\\s*\\("
+      - type: "output_matches"
+        pattern: "await\\s+foreach"
+      - type: "output_matches"
+        pattern: "\\.Content\\b|ProcessOutputLine"
+      - type: "output_matches"
+        pattern: "\\.StandardError\\b"
+      - type: "output_not_matches"
+        pattern: "OutputDataReceived|BeginOutputReadLine"
+    rubric:
+      - "Uses Process.ReadAllLinesAsync consumed with `await foreach` over IAsyncEnumerable<ProcessOutputLine>"
+      - "Reads ProcessOutputLine.Content and distinguishes stdout vs stderr via .StandardError"
+      - "Does NOT use the old OutputDataReceived/BeginOutputReadLine event model; targets net11.0"
+    timeout: 180
+
+  # --- Scenario 5: Negative — skill should NOT activate on .NET 8 ---
+  - name: "Non-activation: Running a process on .NET 8"
+    prompt: |
+      I have a .NET 8 console app and I need to start a process 'notepad.exe'.
+      Show me a minimal C# program and the `.csproj` XML targeting `net8.0` that starts this process using the traditional Process.Start. Print both in your response.
+    expect_activation: false
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "net8\\.0"
+      - type: "output_matches"
+        pattern: "Process\\.Start\\("
+      - type: "output_not_matches"
+        pattern: "RunAndCaptureText|ReadAllTextAsync|ReadAllLinesAsync|KillOnParentExit"
+    rubric:
+      - "Solves the task using standard pre-.NET 11 APIs (Process.Start)"
+      - "Does NOT load or reference the process-api-net11 skill"
+      - "Targets net8.0"
+    timeout: 180
+
+  # --- Scenario 6: subtle non-activation — capture output on .NET 10 (APIs are net11-only) ---
+  - name: "Non-activation: capture process output on .NET 10"
+    prompt: |
+      I'm on a `.NET 10` project (`net10.0`). I need to run `git` with the argument `status`
+      and capture its standard output into a string. Show a minimal C# program and the
+      `.csproj` XML targeting `net10.0`, and print both.
+    expect_activation: false
+    assertions:
+      - type: "exit_success"
+      - type: "output_matches"
+        pattern: "net10\\.0"
+      - type: "output_not_matches"
+        pattern: "RunAndCaptureText|ReadAllTextAsync|ReadAllLinesAsync"
+      - type: "output_matches"
+        pattern: "RedirectStandardOutput|ReadToEnd"
+    rubric:
+      - "Solves the task with pre-.NET 11 APIs (RedirectStandardOutput + ReadToEnd/ReadToEndAsync)"
+      - "Recognizes the new .NET 11 Process convenience APIs are unavailable on net10.0 and does not use them"
+      - "Does NOT load the process-api-net11 skill; targets net10.0"
+    timeout: 180