loc-rs 0.2.7

// Author: kelexine (https://github.com/kelexine)
// extractors/swift.rs — Swift function/class extraction via Tree-sitter

use super::Extractor;
use super::tree_sitter::ast_complexity;
use crate::models::FunctionInfo;
use tree_sitter::Node;

pub struct SwiftExtractor;

impl Extractor for SwiftExtractor {
    fn extract(&self, content: &str) -> Vec<FunctionInfo> {
        super::with_parsed_tree(tree_sitter_swift::LANGUAGE.into(), content, |tree| {
            let mut functions = Vec::new();
            traverse(tree.root_node(), content, &mut functions, false);
            functions.sort_by_key(|f| f.line_start);
            functions
        })
        .unwrap_or_default()
    }
}

fn traverse(
    node: Node,
    content: &str,
    functions: &mut Vec<FunctionInfo>,
    in_class: bool,
) {
    let kind = node.kind();

    if kind == "function_declaration" || kind == "init_declaration" {
        if let Some(info) = parse_function(node, content, in_class) {
            functions.push(info);
        }
    } else if (kind == "class_declaration"
        || kind == "struct_declaration"
        || kind == "enum_declaration"
        || kind == "protocol_declaration"
        || kind == "extension_declaration")
        && let Some(info) = parse_class(node, content)
    {
        functions.push(info);
    }

    let is_class_body = matches!(
        kind,
        "class_body" | "struct_body" | "enum_body" | "protocol_body" | "extension_body"
    );

    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        traverse(child, content, functions, in_class || is_class_body);
    }
}

fn parse_function(
    node: Node,
    content: &str,
    is_method: bool,
) -> Option<FunctionInfo> {
    let mut name = String::new();
    let mut parameters = Vec::new();
    let mut is_async = false;
    let mut is_explicit_method = is_method;

    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        let kind = child.kind();
        if kind == "simple_identifier" && name.is_empty() {
            name = child.utf8_text(content.as_bytes()).unwrap_or("").to_string();
        } else if kind == "parameter" {
            parameters.push(child.utf8_text(content.as_bytes()).unwrap_or("").to_string());
        } else if kind == "modifiers" {
            let mod_text = child.utf8_text(content.as_bytes()).unwrap_or("");
            if mod_text.contains("mutating")
                || mod_text.contains("override")
                || mod_text.contains("static")
                || mod_text.contains("class")
            {
                is_explicit_method = true;
            }
        } else if kind == "async" {
            is_async = true;
        }
    }

    if node.kind() == "init_declaration" {
        name = "init".to_string();
    }

    if name.is_empty() {
        return None;
    }

    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    let complexity = ast_complexity(node, content.as_bytes());

    Some(FunctionInfo {
        name,
        line_start: start_line,
        line_end: end_line,
        parameters,
        is_async,
        is_method: is_explicit_method,
        is_class: false,
        docstring: None,
        decorators: vec![],
        complexity,
    })
}

fn parse_class(node: Node, content: &str) -> Option<FunctionInfo> {
    let mut name = String::new();

    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        if child.kind() == "type_identifier" && name.is_empty() {
            name = child.utf8_text(content.as_bytes()).unwrap_or("").to_string();
            break;
        }
    }

    if name.is_empty() {
        name = "?".to_string();
    }

    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    Some(FunctionInfo {
        name,
        line_start: start_line,
        line_end: end_line,
        parameters: vec![],
        is_async: false,
        is_method: false,
        is_class: true,
        docstring: None,
        decorators: vec![],
        complexity: 1,
    })
}

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

    #[test]
    fn test_extract_swift_functions() {
        let content = r#"
import Foundation
func hello() {}
public func fetchData() async -> Data? { return nil }
class Service {
    override func start() {}
}
struct Point {
    var x, y: Double
    mutating func moveBy(x deltaX: Double, y deltaY: Double) {}
}
"#;
        let extractor = SwiftExtractor;
        let mut fns = extractor.extract(content);
        fns.sort_by(|a, b| a.name.cmp(&b.name));

        assert_eq!(fns.len(), 6);

        let c = fns.iter().find(|f| f.name == "Service").unwrap();
        assert!(c.is_class);

        let p = fns.iter().find(|f| f.name == "Point").unwrap();
        assert!(p.is_class);

        let h = fns.iter().find(|f| f.name == "hello").unwrap();
        assert!(!h.is_method);

        let m = fns.iter().find(|f| f.name == "moveBy").unwrap();
        assert!(m.is_method);
        assert_eq!(m.parameters, vec!["x deltaX: Double", "y deltaY: Double"]);

        let f = fns.iter().find(|f| f.name == "fetchData").unwrap();
        assert!(f.is_async);
    }
}