az_minigrep 0.1.0

//! This crate provides two search functions `search` and `search_case_insensitive`
//! to query a string from another multi-line string.
pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    contents
        .lines()
        .filter(|line| line.contains(&query))
        .collect()
}

pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    let query = query.to_lowercase();

    contents
        .lines()
        .filter(|line| line.to_lowercase().contains(&query))
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn case_sensitive() {
        let query = "duct";
        let contents = "\
Rust:
safe, fast, productive.
Pick threee.
Duct Tape";

        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
    }

    #[test]
    fn case_insensitive() {
        let query = "rUsT";
        let contents = "\
Rust:
safe, fast, productive.
Pick threee.
Trust me!";

        assert_eq!(
            vec!["Rust:", "Trust me!"],
            search_case_insensitive(query, contents)
        );
    }

    #[test]
    fn match_nothing() {
        let query = "nonexist";
        let contents = "\
To all of you,
I love Rust.
It's so good for the system programming.";
        assert_eq!(0, search(query, contents).len());
    }
}