lib.rs

use std::fs;
use std::env;
use std::error::Error;
 
pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.file_path)?;
 
    let results = if config.ignore_case {
        search_case_insensitive(&config.query, &contents)
    } else {
        search(&config.query, &contents)
    };
 
    for line in results {
        println!("{line}");
    }
    
    Ok(())
}
 
pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    // let mut results = Vec::new();
 
    // for line in contents.lines() {
    //     if line.contains(query) {
    //         results.push(line);
    //     }
    // }
 
    // results
 
    contents.lines().filter(|line| line.contains(query)).collect()
}
 
pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool,
}
 
pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    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
}
 
impl Config {
    pub fn build(mut args: impl Iterator<Item = String>,) -> Result<Config, &'static str> {
        // First arg is the binary name, so we ignore it
        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 })
    }
}
 
#[cfg(test)]
mod tests {
    use super::*;
 
    #[test]
    fn case_sensitive() {
        let query = "safe";
        let contents = "\
Rust:
safe, fast, productive.
Billo bagge billeyan da ki karegi, bagge bagge billeyan da ki karegi.";
 
        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
    }
 
    #[test]
    fn case_insensitive() {
        let query = "rUsT";
        let contents = "\
Rust:
safe, fast, productive.
Bharosa kar.";
 
        assert_eq!(vec!["Rust:"], search_case_insensitive(query, contents));
    }
}