sourceatlas 0.1.1

pub struct FileStats {
    pub(crate) total_lines: usize,
    pub(crate) total_characters: usize,
    pub(crate) total_blank_lines: usize,
    pub(crate) total_non_blank_lines: usize,
    pub(crate) total_functions: usize,
    pub(crate) total_todos: usize,
}

impl FileStats {
    pub fn new(source: &str) -> Self {
        Self {
            total_lines: count_file_lines(source),
            total_characters: count_file_non_whitespace_characters(source),
            total_blank_lines: count_file_blank_lines(source),
            total_non_blank_lines: count_file_non_blank_lines(source),
            total_functions: count_file_functions(source),
            total_todos: count_file_todos(source),
        }
    }
}

fn count_file_lines(source: &str) -> usize {
    source.lines().count()
}

fn count_file_non_whitespace_characters(source: &str) -> usize {
    source.chars().filter(|char| !char.is_whitespace()).count()
}

fn count_file_non_blank_lines(source: &str) -> usize {
    source
        .lines()
        .filter(|line| !line.trim().is_empty())
        .count()
}

fn count_file_blank_lines(source: &str) -> usize {
    source.lines().filter(|line| line.trim().is_empty()).count()
}

fn count_file_functions(source: &str) -> usize {
    source
        .lines()
        .filter(|line| {
            let line = line.trim_start();
            line.starts_with("fn")
        })
        .count()
}

fn count_file_todos(source: &str) -> usize {
    source.to_ascii_lowercase().matches("todo").count()
}

#[cfg(test)]
mod tests {
    use super::*;

    const TEST_SOURCE: &str = r#"fn main() {
        let first_name = "John";
        // TODO: add last name

    }"#;

    #[test]
    fn counts_lines() {
        assert_eq!(5, count_file_lines(TEST_SOURCE))
    }

    #[test]
    fn counts_blank_lines() {
        assert_eq!(1, count_file_blank_lines(TEST_SOURCE))
    }

    #[test]
    fn counts_non_whitespace_characters() {
        assert_eq!(49, count_file_non_whitespace_characters(TEST_SOURCE))
    }

    #[test]
    fn counts_todos() {
        assert_eq!(1, count_file_todos(TEST_SOURCE))
    }

    #[test]
    fn counts_functions() {
        assert_eq!(1, count_file_functions(TEST_SOURCE))
    }
}