shaygrep 0.1.0

Minigrep from the Rust Book, for my practice
Documentation
use std::error::Error;
use std::fs;
use std::env;

pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool,
}

impl Config {
    pub fn build(mut args: impl Iterator<Item = String>) -> Result<Config, &'static str> {

        args.next();

        let query= match args.next() {
            Some(arg) => arg,
            None => return Err("Didn't get query"),
        };

        let file_path = match args.next() {
            Some(arg) => arg,
            None => return Err("Didn't get filename"),
        };

        let ignore_case = env::var("IGNORE_CASE").is_ok();

        Ok(Config { 
            query, 
            file_path,
            ignore_case })
    }
}

pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents =
        fs::read_to_string(config.file_path)?;


    let results;
    if config.ignore_case {
        results = search_case_insensitive(&config.query, &contents);
    } else {
        results = search(&config.query, &contents);
    }

    for line in results {
        println!("{line}");
    }

    Ok(())
}

pub fn search<'a> (query: &str, contents: &'a str) -> Vec<&'a str> {
    // for line in contents.lines() {
    //     if line.contains(query) {
    //         results.push(line);
    //     }
    // }
    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 three.
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 three.
Duct tape.
Trust me.";
        assert_eq!(vec!["Rust:", "Trust me."], search_case_insensitive(query, contents))
    }
}