Runic.CommandLine.Testing 0.7.0-preview.2

Runic.CommandLine.Testing

Use this package in tests for deterministic command invocation fixtures. It provides an in-memory console, a simple scope factory, parsed invocations, captured parse settings, an already-cancelled token, and JSON envelope parsing without reading or mutating process-global state.

Test the whole application

var tester = new CommandAppTester(console => new CommandApp(catalog)
{
    Console = console,
    ParseSettings = ParseSettings.Default,
    HandleCancelKeyPress = false,
});
var result = await tester.RunAsync(["greet", "Ada", "--output=json"]);
using var frame = CommandTestEnvelope.Parse(result.StandardOutput);

For prompt tests, construct TestCommandConsole with explicit capability flags and call QueueInput. Each tester run gets fresh output buffers.

Test a continuation

Run is the synchronous counterpart of RunAsync. It runs the application with CommandApp.Run, so a command that hands a continuation back with CommandExecutionContext.ContinueOnCallingThread has it run on the thread that calls Run:

CommandAppTestResult result = tester.Run(["ui", "--no-open"]);

ExitCode is the continuation's result, or the invocation's exit code when it failed or handed nothing back. StandardOutput and StandardError are captured after the continuation returned. Call it from a test that does not hold a SynchronizationContext the handler depends on; the invocation itself runs without one.

Script prompt answers

CommandPrompts reads one line per prompt from an interactive TestCommandConsole. Supply the console through CreateConsole:

var tester = new CommandAppTester(console => new CommandApp(catalog) { Console = console, ParseSettings = ParseSettings.Default })
{
    CreateConsole = () =>
    {
        var console = new TestCommandConsole { IsInteractive = true };
        console.QueueInput("2");      // the second choice of a select, or its label
        console.QueueInput("y");      // a confirm
        return console;
    },
};

A queued null is the end of input, which cancels the command (exit code 4). The default noninteractive console never asks: prompts return their defaults or fail with RCLI4001. To drive the redrawn terminal prompts, set SupportsAnsi = true (with SupportsUnicode and Width as needed) and queue keys with QueueKey(ConsoleKey.DownArrow), QueueKey(ConsoleKey.Enter) or QueueText("name\n"). Their frames, ANSI sequences included, are captured in StandardError. ReadKeyAsync waits until a key is queued or the token is cancelled, which lets a test cancel a waiting prompt. Keep a reference to the console you create and check PendingInputCount and PendingKeyCount to make sure every queued answer was used.