rs-assert-cmd

Ergonomic CLI binary integration testing with fluent assertions on stdout, stderr, and exit code

Installation

[dependencies]
philiprehberger-assert-cmd = "0.1.3"

Usage

use philiprehberger_assert_cmd::cmd;

// Basic command assertion
cmd("echo")
    .arg("hello world")
    .run()
    .unwrap()
    .assert_success()
    .assert_stdout_contains("hello");

// Chain multiple assertions
cmd("rustc")
    .arg("--version")
    .run()
    .unwrap()
    .assert_success()
    .assert_exit_code(0)
    .assert_stdout_contains("rustc")
    .assert_stderr_is_empty();

// Environment variables and stdin
cmd("cat")
    .stdin("input data\n")
    .run()
    .unwrap()
    .assert_success()
    .assert_stdout_equals("input data\n");

// Glob pattern matching
cmd("echo")
    .arg("version 1.2.3")
    .run()
    .unwrap()
    .assert_stdout_matches("version *");

API

Builder

Method	Description
`cmd(program)`	Create a new command builder
`Cmd::new(program)`	Create a new command builder
`.arg(arg)`	Append a single argument
`.args(&[args])`	Append multiple arguments
`.env(key, value)`	Set an environment variable
`.stdin(data)`	Pipe data to stdin
`.current_dir(dir)`	Set the working directory
`.timeout(duration)`	Set a timeout for execution
`.run()`	Execute and return `Result<CmdOutput, CmdError>`

Assertions

Method	Description
`.assert_success()`	Exit code is 0
`.assert_failure()`	Exit code is non-zero
`.assert_exit_code(code)`	Exit code matches exactly
`.assert_stdout_contains(s)`	Stdout contains substring
`.assert_stdout_equals(s)`	Stdout equals exactly
`.assert_stdout_is_empty()`	Stdout is empty
`.assert_stdout_line_count(n)`	Stdout has n lines
`.assert_stdout_matches(pat)`	Stdout matches glob pattern (`*`, `?`)
`.assert_stderr_contains(s)`	Stderr contains substring
`.assert_stderr_equals(s)`	Stderr equals exactly
`.assert_stderr_is_empty()`	Stderr is empty
`.stdout_lines()`	Split stdout into `Vec<&str>`

Development

cargo test
cargo clippy -- -D warnings

Support

If you find this package useful, consider giving it a star on GitHub — it helps motivate continued maintenance and development.

License

MIT

philiprehberger-assert-cmd 0.1.3