implement the minigrep project with basic features

Author: Syaw0

projects/minigrep/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "minigrep"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

projects/minigrep/src/lib.rs

@@ -0,0 +1,82 @@
+use std::{ error::Error, fs, vec };
+
+pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(&config.filepath)?;
+
+    search(&config.query, &contents)
+        .iter()
+        .for_each(|line| { println!("{line}") });
+
+    Ok(())
+}
+
+#[derive(Debug)]
+pub struct Config {
+    query: String,
+    filepath: String,
+}
+
+impl Config {
+    pub fn build(mut args: Vec<String>) -> Result<Config, &'static str> {
+        if args.len() < 3 {
+            return Err("Not Enough Arguments");
+        }
+        let query = args.remove(1);
+        let filepath = args.remove(1);
+
+        Ok(Config {
+            query,
+            filepath,
+        })
+    }
+}
+
+fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let mut results = vec![];
+
+    contents.lines().for_each(|line| {
+        if line.contains(query) {
+            results.push(line);
+        }
+    });
+
+    results
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn none_result() {
+        let query = "threee";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(vec![] as Vec<&str>, search(query, contents))
+    }
+
+    #[test]
+    fn one_result() {
+        let query = "duct";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(vec!["safe, fast, productive."], search(query, contents))
+    }
+
+    #[test]
+    fn two_result() {
+        let query = "i";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(vec!["safe, fast, productive.", "Pick three."], search(query, contents))
+    }
+}

projects/minigrep/src/main.rs

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+use std::{ env, process };
+
+use minigrep::Config;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+
+    let config: Config = Config::build(args).unwrap_or_else(|err| {
+        println!("Problem parsing arguments: {err}");
+        process::exit(1);
+    });
+
+    if let Err(e) = minigrep::run(config) {
+        println!("Application error: {e}");
+        process::exit(1);
+    }
+}