RustBrock/minigrep/src/lib.rs

use std::fs;
use std::error::Error;
use std::env;

// refactor 9
pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool,
}

impl Config {
    // refactor 14
    // pub fn build(args: &[String]) -> Result<Config, &'static str> {
    //     if args.len() < 3 {
    //         return Err("not enough arguments");
    //     }

    //     let query = args[1].clone();
    //     let file_path = args[2].clone();

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

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

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

        // skip first value in iterator, value inside is name of program
        args.next();

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

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

        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)?;

    // refactor 10
    // println!("With text:\n{contents}")
    // refactor 12
    let results = if config.ignore_case {
        search_case_insensitive(&config.query, &contents)
    } else {
        search(&config.query, &contents)
    };

    // refactor 12
    // for line in search(&config.query, &contents) {
    //     println!("{line}");
    // }

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

    Ok(())
}

pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    // refacotr 15
    // // original that only can fail
    // // vec![]
    // let mut results = Vec::new();

    // for line in contents.lines() {
    //     if line.contains(query) {
    //         // do something with line
    //         results.push(line);
    //     }
    // }
    // results

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

pub fn search_case_insensitive<'a>(
    query: &str, 
    contents: &'a str
) -> Vec<&'a str> {
    // orignal that only fails
    // vec![]

    let query = query.to_lowercase();
    let mut results = Vec::new();

    for line in contents.lines() {
        if line.to_lowercase().contains(&query) {
            results.push(line);
        }
    }
    results
}

#[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.
Trust me.";

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