use assert_cmd::prelude::*; // Add methods on commands
use predicates::prelude::*; // Used for writing assertions
use std::process::Command; // Run programs
use assert_fs::prelude::*;
use rust_demo_rgrep::{answer, find_matches};

#[test]
fn check_answer_validity() {
    assert_eq!(answer(), 42);
}

#[test]
fn find_a_match() {
    let mut result = Vec::new();
    find_matches("lorem ipsum\ndolor sit amet", "lorem", &mut result);
    assert_eq!(result, b"lorem ipsum\n");
}

#[test]
fn file_doesnt_exist() -> Result<(), Box<dyn std::error::Error>> {
    let mut cmd = Command::cargo_bin("rust-demo-rgrep")?;

    cmd.arg("main").arg("src/main.rs");
    cmd.assert()
        .failure()
        .stderr(predicate::str::contains("could not read file"));

    Ok(())
}

#[test]
fn find_content_in_file() -> Result<(), Box<dyn std::error::Error>> {
    let file = assert_fs::NamedTempFile::new("sample.txt")?;
    file.write_str("A test\nActual content\nMore content\nAnother test")?;

    let mut cmd = Command::cargo_bin("rust-demo-rgrep")?;
    cmd.arg("test").arg(file.path());
    cmd.assert()
        .success()
        .stdout(predicate::str::contains("A test\nAnother test"));

    Ok(())
}