RTK Code Simplifier

Review and simplify Rust code in RTK while respecting the project's constraints.

Constraints (never simplify away)

• lazy_static! regex — cannot be moved inside functions even if "simpler"

• .context() on every ? — verbose but mandatory

• Fallback to raw command — never remove even if it looks like dead code

• Exit code propagation — never simplify to Ok(())

• #[cfg(test)] mod tests — never remove test modules

Simplification Patterns

1. Iterator chains over manual loops

// ❌ Verbose

let mut result = Vec::new();

for line in input.lines() {

    let trimmed = line.trim();

    if !trimmed.is_empty() && trimmed.starts_with("error") {

        result.push(trimmed.to_string());

    }

}

// ✅ Idiomatic

let result: Vec<String> = input.lines()

    .map(|l| l.trim())

    .filter(|l| !l.is_empty() &#x26;&#x26; l.starts_with("error"))

    .map(str::to_string)

    .collect();

2. String building

// ❌ Verbose push loop

let mut out = String::new();

for (i, line) in lines.iter().enumerate() {

    out.push_str(line);

    if i < lines.len() - 1 {

        out.push('\n');

    }

}

// ✅ join

let out = lines.join("\n");

3. Option/Result chaining

// ❌ Nested match

let result = match maybe_value {

    Some(v) => match transform(v) {

        Ok(r) => r,

        Err(_) => default,

    },

    None => default,

};

// ✅ Chained

let result = maybe_value

    .and_then(|v| transform(v).ok())

    .unwrap_or(default);

4. Struct destructuring

// ❌ Repeated field access

fn process(args: &MyArgs) -> String {

    format!("{} {}", args.command, args.subcommand)

}

// ✅ Destructure

fn process(&MyArgs { ref command, ref subcommand, .. }: &MyArgs) -> String {

    format!("{} {}", command, subcommand)

}

5. Early returns over nesting

// ❌ Deeply nested

fn filter(input: &#x26;str) -> Option<String> {

    if !input.is_empty() {

        if let Some(line) = input.lines().next() {

            if line.starts_with("error") {

                return Some(line.to_string());

            }

        }

    }

    None

}

// ✅ Early return

fn filter(input: &#x26;str) -> Option<String> {

    if input.is_empty() { return None; }

    let line = input.lines().next()?;

    if !line.starts_with("error") { return None; }

    Some(line.to_string())

}

6. Avoid redundant clones

// ❌ Unnecessary clone

fn filter_output(input: &str) -> String {

    let s = input.to_string();  // Pointless clone

    s.lines().filter(|l| !l.is_empty()).collect::<Vec<_>>().join("\n")

}

// ✅ Work with &#x26;str

fn filter_output(input: &#x26;str) -> String {

    input.lines().filter(|l| !l.is_empty()).collect::<Vec<_>>().join("\n")

}

7. Use if let for single-variant match

// ❌ Full match for one variant

match output {

    Ok(s) => process(&s),

    Err(_) => {},

}

// ✅ if let (but still handle errors in RTK — don't silently drop)

if let Ok(s) = output {

    process(&s);

}

// Note: in RTK filters, always handle Err with eprintln! + fallback

RTK-Specific Checks

Run these after simplification:

# Verify no regressions

cargo fmt --all && cargo clippy --all-targets && cargo test

# Verify no new regex in functions

grep -n "Regex::new" src/<file>.rs

# All should be inside lazy_static! blocks

# Verify no new unwrap in production

grep -n "\.unwrap()" src/<file>.rs

# Should only appear inside #[cfg(test)] blocks

What NOT to Simplify

• lazy_static! { static ref RE: Regex = Regex::new(...).unwrap(); } — the .unwrap() here is acceptable, it's init-time

• .context("description")? chains — verbose but required

• The fallback match arm Err(e) => { eprintln!(...); raw_output } — looks redundant but is the safety net

• std::process::exit(code) at end of run() — looks like it could be Ok(())but it isn't