astmap_languages/language/

python.rs

use std::path::{Path, PathBuf};

use tree_sitter::Language;

use astmap_core::model::SymbolKind;

use super::{
    find_enclosing_symbol, first_line, node_text, parse_with_tree_sitter, symbol_from_node,
    ExtractedCall, ExtractedImport, ExtractedSymbol, ExtractedTypeRef, LanguageParser,
    LanguageResolver, LanguageSupport, ParseResult,
};

pub(super) fn lang() -> LanguageSupport {
    LanguageSupport {
        name: "python",
        extensions: &["py"],
        parser: &PythonParser,
        resolver_factory: |_root| Box::new(PythonResolver),
        config_files: &["pyproject.toml"],
        sibling_fn: python_sibling_expansion,
    }
}

fn python_sibling_expansion(rel_path: &str) -> Option<astmap_core::SiblingExpansion> {
    let dir = rel_path
        .strip_suffix("__init__.py")
        .filter(|p| !p.is_empty())?;
    Some(astmap_core::SiblingExpansion {
        prefix: dir.to_string(),
        extension: "py".to_string(),
        root_only: false,
    })
}

// ── Parser ──

pub(crate) struct PythonParser;

impl LanguageParser for PythonParser {
    fn parse(&self, source: &str, _file_path: &Path) -> ParseResult {
        parse_python_file(source)
    }

    fn language_name(&self) -> &str {
        "python"
    }
}

fn python_language() -> Language {
    tree_sitter_python::LANGUAGE.into()
}

fn parse_python_file(source: &str) -> ParseResult {
    parse_with_tree_sitter(
        source,
        &python_language(),
        |root, src, symbols, imports| extract_from_node(root, src, symbols, imports, None),
        extract_calls,
        extract_type_refs,
    )
}

// ---------------------------------------------------------------------------
// Symbol extraction
// ---------------------------------------------------------------------------

fn extract_from_node(
    node: tree_sitter::Node,
    source: &str,
    symbols: &mut Vec<ExtractedSymbol>,
    imports: &mut Vec<ExtractedImport>,
    parent_index: Option<usize>,
) {
    match node.kind() {
        "function_definition" => {
            if let Some(sym) = extract_function(&node, source, parent_index) {
                symbols.push(sym);
                return; // don't recurse into body for nested symbol extraction
            }
        }
        "class_definition" => {
            if let Some(sym) = extract_class(&node, source, parent_index) {
                let idx = symbols.len();
                symbols.push(sym);
                // Recurse into body to extract methods
                if let Some(body) = node.child_by_field_name("body") {
                    for i in 0..body.child_count() {
                        if let Some(child) = body.child(i as u32) {
                            extract_from_node(child, source, symbols, imports, Some(idx));
                        }
                    }
                }
                return;
            }
        }
        "decorated_definition" => {
            extract_decorated(&node, source, symbols, imports, parent_index);
            return;
        }
        "expression_statement" if parent_index.is_none() => {
            // Module-level assignments: extract constants
            for i in 0..node.child_count() {
                if let Some(child) = node.child(i as u32) {
                    if child.kind() == "assignment" {
                        if let Some(sym) = extract_module_constant(&child, &node, source) {
                            symbols.push(sym);
                        }
                    }
                }
            }
        }
        "import_statement" => {
            imports.extend(extract_import_plain(&node, source));
        }
        "import_from_statement" => {
            if let Some(imp) = extract_import_from(&node, source) {
                imports.push(imp);
            }
        }
        _ => {}
    }

    // Default: recurse into children
    for i in 0..node.child_count() {
        if let Some(child) = node.child(i as u32) {
            extract_from_node(child, source, symbols, imports, parent_index);
        }
    }
}

fn extract_function(
    node: &tree_sitter::Node,
    source: &str,
    parent_index: Option<usize>,
) -> Option<ExtractedSymbol> {
    let name_node = node.child_by_field_name("name")?;
    let name = node_text(&name_node, source);
    let kind = if parent_index.is_some() {
        SymbolKind::Method
    } else {
        SymbolKind::Function
    };
    Some(symbol_from_node(name, kind, node, source, parent_index))
}

fn extract_class(
    node: &tree_sitter::Node,
    source: &str,
    parent_index: Option<usize>,
) -> Option<ExtractedSymbol> {
    let name_node = node.child_by_field_name("name")?;
    let name = node_text(&name_node, source);
    Some(symbol_from_node(
        name,
        SymbolKind::Class,
        node,
        source,
        parent_index,
    ))
}

fn extract_decorated(
    node: &tree_sitter::Node,
    source: &str,
    symbols: &mut Vec<ExtractedSymbol>,
    imports: &mut Vec<ExtractedImport>,
    parent_index: Option<usize>,
) {
    // Collect decorator texts
    let decorators: Vec<String> = (0..node.child_count())
        .filter_map(|i| node.child(i as u32))
        .filter(|c| c.kind() == "decorator")
        .map(|c| node_text(&c, source).trim().to_string())
        .collect();

    let def_node = match node.child_by_field_name("definition") {
        Some(d) => d,
        None => return,
    };

    let decorator_prefix = if decorators.is_empty() {
        String::new()
    } else {
        format!("{}\n", decorators.join("\n"))
    };

    match def_node.kind() {
        "function_definition" => {
            if let Some(mut sym) = extract_function(&def_node, source, parent_index) {
                sym.signature = Some(format!(
                    "{}{}",
                    decorator_prefix,
                    first_line(&def_node, source)
                ));
                sym.start_line = node.start_position().row + 1;
                sym.start_byte = node.start_byte();
                symbols.push(sym);
            }
        }
        "class_definition" => {
            if let Some(mut sym) = extract_class(&def_node, source, parent_index) {
                sym.signature = Some(format!(
                    "{}{}",
                    decorator_prefix,
                    first_line(&def_node, source)
                ));
                sym.start_line = node.start_position().row + 1;
                sym.start_byte = node.start_byte();
                let idx = symbols.len();
                symbols.push(sym);
                if let Some(body) = def_node.child_by_field_name("body") {
                    for i in 0..body.child_count() {
                        if let Some(child) = body.child(i as u32) {
                            extract_from_node(child, source, symbols, imports, Some(idx));
                        }
                    }
                }
            }
        }
        _ => {}
    }
}

fn extract_module_constant(
    assignment: &tree_sitter::Node,
    stmt: &tree_sitter::Node,
    source: &str,
) -> Option<ExtractedSymbol> {
    let left = assignment.child_by_field_name("left")?;
    if left.kind() != "identifier" {
        return None;
    }
    let name = node_text(&left, source);

    let is_all_caps = name.chars().any(|c| c.is_ascii_uppercase())
        && name.chars().all(|c| c.is_ascii_uppercase() || c == '_');
    let has_type_annotation = assignment.child_by_field_name("type").is_some();

    if !is_all_caps && !has_type_annotation {
        return None;
    }

    Some(symbol_from_node(
        name,
        SymbolKind::Variable,
        stmt,
        source,
        None,
    ))
}

// ---------------------------------------------------------------------------
// Import extraction
// ---------------------------------------------------------------------------

fn extract_import_plain(node: &tree_sitter::Node, source: &str) -> Vec<ExtractedImport> {
    let mut imports = Vec::new();
    for i in 0..node.child_count() {
        let child = match node.child(i as u32) {
            Some(c) => c,
            None => continue,
        };
        match child.kind() {
            "dotted_name" => {
                let full_path = node_text(&child, source);
                let last_segment = full_path
                    .rsplit('.')
                    .next()
                    .unwrap_or(&full_path)
                    .to_string();
                imports.push(ExtractedImport {
                    path: full_path,
                    imported_symbols: vec![last_segment],
                });
            }
            "aliased_import" => {
                let name_node = child.child_by_field_name("name");
                let alias_node = child.child_by_field_name("alias");
                if let Some(name) = name_node {
                    let path = node_text(&name, source);
                    let symbol = alias_node
                        .map(|a| node_text(&a, source))
                        .unwrap_or_else(|| path.rsplit('.').next().unwrap_or(&path).to_string());
                    imports.push(ExtractedImport {
                        path,
                        imported_symbols: vec![symbol],
                    });
                }
            }
            _ => {}
        }
    }
    imports
}

fn extract_import_from(node: &tree_sitter::Node, source: &str) -> Option<ExtractedImport> {
    let module_node = node.child_by_field_name("module_name")?;
    let path = node_text(&module_node, source);

    // Check for wildcard import
    let has_wildcard = (0..node.child_count())
        .filter_map(|i| node.child(i as u32))
        .any(|c| c.kind() == "wildcard_import");

    if has_wildcard {
        return Some(ExtractedImport {
            path,
            imported_symbols: vec![],
        });
    }

    // Collect named imports
    let module_node_id = module_node.id();
    let mut imported_symbols = Vec::new();
    for i in 0..node.child_count() {
        let child = match node.child(i as u32) {
            Some(c) => c,
            None => continue,
        };
        match child.kind() {
            "dotted_name" if child.id() != module_node_id => {
                imported_symbols.push(node_text(&child, source));
            }
            "aliased_import" => {
                if let Some(alias) = child.child_by_field_name("alias") {
                    imported_symbols.push(node_text(&alias, source));
                } else if let Some(name) = child.child_by_field_name("name") {
                    let text = node_text(&name, source);
                    let last = text.rsplit('.').next().unwrap_or(&text).to_string();
                    imported_symbols.push(last);
                }
            }
            _ => {}
        }
    }

    Some(ExtractedImport {
        path,
        imported_symbols,
    })
}

// ---------------------------------------------------------------------------
// Call extraction
// ---------------------------------------------------------------------------

fn extract_calls(
    node: tree_sitter::Node,
    source: &str,
    symbols: &[ExtractedSymbol],
) -> Vec<ExtractedCall> {
    let mut calls = Vec::new();
    collect_calls(node, source, symbols, &mut calls);
    calls
}

fn collect_calls(
    node: tree_sitter::Node,
    source: &str,
    symbols: &[ExtractedSymbol],
    calls: &mut Vec<ExtractedCall>,
) {
    if node.kind() == "call" {
        if let Some(func_node) = node.child_by_field_name("function") {
            let callee_name = match func_node.kind() {
                "attribute" => func_node
                    .child_by_field_name("attribute")
                    .map(|a| node_text(&a, source))
                    .unwrap_or_else(|| node_text(&func_node, source)),
                "identifier" => node_text(&func_node, source),
                _ => node_text(&func_node, source),
            };

            if !is_python_builtin(&callee_name) {
                let call_line = node.start_position().row + 1;
                if let Some(caller) = find_enclosing_symbol(symbols, call_line) {
                    calls.push(ExtractedCall {
                        caller_name: caller.to_string(),
                        callee_name,
                        line: call_line,
                    });
                }
            }
        }
    }

    for i in 0..node.child_count() {
        if let Some(child) = node.child(i as u32) {
            collect_calls(child, source, symbols, calls);
        }
    }
}

fn is_python_builtin(name: &str) -> bool {
    matches!(
        name,
        "print"
            | "len"
            | "range"
            | "enumerate"
            | "zip"
            | "map"
            | "filter"
            | "sorted"
            | "reversed"
            | "list"
            | "dict"
            | "set"
            | "tuple"
            | "str"
            | "int"
            | "float"
            | "bool"
            | "bytes"
            | "bytearray"
            | "type"
            | "isinstance"
            | "issubclass"
            | "hasattr"
            | "getattr"
            | "setattr"
            | "delattr"
            | "callable"
            | "super"
            | "property"
            | "staticmethod"
            | "classmethod"
            | "abs"
            | "all"
            | "any"
            | "ascii"
            | "bin"
            | "chr"
            | "complex"
            | "dir"
            | "divmod"
            | "format"
            | "globals"
            | "hash"
            | "hex"
            | "id"
            | "input"
            | "iter"
            | "max"
            | "min"
            | "next"
            | "oct"
            | "open"
            | "ord"
            | "pow"
            | "repr"
            | "round"
            | "slice"
            | "sum"
            | "vars"
            | "object"
            | "Exception"
            | "ValueError"
            | "TypeError"
            | "KeyError"
            | "IndexError"
            | "AttributeError"
            | "RuntimeError"
            | "StopIteration"
            | "NotImplementedError"
            | "OSError"
            | "IOError"
    )
}

// ---------------------------------------------------------------------------
// Type reference extraction
// ---------------------------------------------------------------------------

fn extract_type_refs(
    node: tree_sitter::Node,
    source: &str,
    symbols: &[ExtractedSymbol],
) -> Vec<ExtractedTypeRef> {
    let mut refs = Vec::new();
    collect_type_refs(node, source, symbols, &mut refs);
    refs
}

fn collect_type_refs(
    node: tree_sitter::Node,
    source: &str,
    symbols: &[ExtractedSymbol],
    refs: &mut Vec<ExtractedTypeRef>,
) {
    if node.kind() == "type" {
        collect_type_identifiers(node, source, symbols, refs);
        return; // don't double-recurse
    }

    for i in 0..node.child_count() {
        if let Some(child) = node.child(i as u32) {
            collect_type_refs(child, source, symbols, refs);
        }
    }
}

fn collect_type_identifiers(
    node: tree_sitter::Node,
    source: &str,
    symbols: &[ExtractedSymbol],
    refs: &mut Vec<ExtractedTypeRef>,
) {
    if node.kind() == "identifier" {
        let name = node_text(&node, source);
        if !is_python_builtin_type(&name) {
            let line = node.start_position().row + 1;
            if let Some(from_sym) = find_enclosing_symbol(symbols, line) {
                refs.push(ExtractedTypeRef {
                    from_symbol: from_sym.to_string(),
                    to_type: name,
                    line,
                });
            }
        }
    }

    for i in 0..node.child_count() {
        if let Some(child) = node.child(i as u32) {
            collect_type_identifiers(child, source, symbols, refs);
        }
    }
}

fn is_python_builtin_type(name: &str) -> bool {
    matches!(
        name,
        "int"
            | "float"
            | "str"
            | "bool"
            | "bytes"
            | "bytearray"
            | "None"
            | "list"
            | "dict"
            | "set"
            | "tuple"
            | "frozenset"
            | "object"
            | "type"
            | "Any"
            | "Union"
            | "Optional"
            | "List"
            | "Dict"
            | "Set"
            | "Tuple"
            | "FrozenSet"
            | "Type"
            | "Callable"
            | "Iterator"
            | "Generator"
            | "Coroutine"
            | "Awaitable"
            | "Sequence"
            | "Mapping"
            | "MutableMapping"
            | "Iterable"
            | "ClassVar"
            | "Final"
            | "Literal"
            | "Protocol"
            | "Self"
            | "Never"
            | "NoReturn"
            | "TypeVar"
    )
}

// ── Resolver ──

pub(crate) struct PythonResolver;

impl LanguageResolver for PythonResolver {
    fn resolve_import(
        &self,
        import_path: &str,
        source_file: &str,
        project_root: &Path,
    ) -> Option<PathBuf> {
        resolve_python_import(import_path, source_file, project_root)
    }
}

fn resolve_python_import(
    import_path: &str,
    source_file: &str,
    project_root: &Path,
) -> Option<PathBuf> {
    if import_path.is_empty() {
        return None;
    }

    if import_path.starts_with('.') {
        resolve_relative_import(import_path, source_file, project_root)
    } else {
        resolve_absolute_import(import_path, project_root)
    }
}

fn resolve_absolute_import(import_path: &str, project_root: &Path) -> Option<PathBuf> {
    let parts: Vec<&str> = import_path.split('.').collect();

    // Try from project root directly
    if let Some(resolved) = resolve_module_path(&parts, project_root) {
        return Some(resolved);
    }

    // Try from common source directories
    for src_dir in &["src", "lib"] {
        let base = project_root.join(src_dir);
        if base.is_dir() {
            if let Some(resolved) = resolve_module_path(&parts, &base) {
                return Some(resolved);
            }
        }
    }

    // External package
    None
}

fn resolve_relative_import(
    import_path: &str,
    source_file: &str,
    project_root: &Path,
) -> Option<PathBuf> {
    let dot_count = import_path.chars().take_while(|&c| c == '.').count();
    let remainder = &import_path[dot_count..];

    let source_abs = project_root.join(source_file);
    let source_dir = source_abs.parent()?;

    // Walk up (dot_count - 1) levels from source directory
    // 1 dot = current package, 2 dots = parent package, etc.
    let mut base = source_dir.to_path_buf();
    for _ in 1..dot_count {
        base = base.parent()?.to_path_buf();
    }

    if remainder.is_empty() {
        // `from . import x` — resolve to __init__.py of base
        let init = base.join("__init__.py");
        if init.exists() {
            return init.canonicalize().ok();
        }
        return None;
    }

    let parts: Vec<&str> = remainder.split('.').collect();
    resolve_module_path(&parts, &base)
}

fn resolve_module_path(parts: &[&str], base: &Path) -> Option<PathBuf> {
    if parts.is_empty() {
        let init = base.join("__init__.py");
        if init.exists() {
            return init.canonicalize().ok();
        }
        return None;
    }

    let mut current = base.to_path_buf();

    for (i, part) in parts.iter().enumerate() {
        if i == parts.len() - 1 {
            // Last segment: try as .py file first, then as package
            let as_file = current.join(format!("{}.py", part));
            if as_file.exists() {
                return as_file.canonicalize().ok();
            }
            let as_package = current.join(part).join("__init__.py");
            if as_package.exists() {
                return as_package.canonicalize().ok();
            }
            return None;
        } else {
            // Intermediate segment: must be a directory
            let next = current.join(part);
            if next.is_dir() {
                current = next;
            } else {
                return None;
            }
        }
    }
    None
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

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

    // --- Parser helpers ---

    fn parse(source: &str) -> ParseResult {
        PythonParser.parse(source, &PathBuf::from("test.py"))
    }

    // --- Symbol extraction ---

    #[test]
    fn test_parse_function() {
        let result = parse("def hello():\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "hello");
        assert_eq!(result.symbols[0].kind, SymbolKind::Function);
        assert!(result.symbols[0].parent_index.is_none());
    }

    #[test]
    fn test_parse_async_function() {
        let result = parse("async def fetch():\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "fetch");
        assert_eq!(result.symbols[0].kind, SymbolKind::Function);
        assert!(result.symbols[0]
            .signature
            .as_ref()
            .unwrap()
            .contains("async"));
    }

    #[test]
    fn test_parse_class_with_methods() {
        let result = parse(
            "class Foo:\n    def bar(self):\n        pass\n    def baz(self):\n        pass\n",
        );
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 3);
        assert_eq!(result.symbols[0].name, "Foo");
        assert_eq!(result.symbols[0].kind, SymbolKind::Class);
        assert_eq!(result.symbols[1].name, "bar");
        assert_eq!(result.symbols[1].kind, SymbolKind::Method);
        assert_eq!(result.symbols[1].parent_index, Some(0));
        assert_eq!(result.symbols[2].name, "baz");
        assert_eq!(result.symbols[2].kind, SymbolKind::Method);
        assert_eq!(result.symbols[2].parent_index, Some(0));
    }

    #[test]
    fn test_parse_class_basic() {
        let result = parse("class Empty:\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "Empty");
        assert_eq!(result.symbols[0].kind, SymbolKind::Class);
    }

    #[test]
    fn test_parse_nested_class() {
        let result = parse("class Outer:\n    class Inner:\n        pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 2);
        assert_eq!(result.symbols[0].name, "Outer");
        assert_eq!(result.symbols[1].name, "Inner");
        assert_eq!(result.symbols[1].kind, SymbolKind::Class);
        assert_eq!(result.symbols[1].parent_index, Some(0));
    }

    #[test]
    fn test_decorated_function() {
        let result = parse("@app.route(\"/\")\ndef index():\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "index");
        assert_eq!(result.symbols[0].kind, SymbolKind::Function);
        let sig = result.symbols[0].signature.as_ref().unwrap();
        assert!(sig.contains("@app.route"), "sig = {}", sig);
        assert!(sig.contains("def index"), "sig = {}", sig);
    }

    #[test]
    fn test_multiple_decorators() {
        let result = parse("@login_required\n@admin_only\ndef admin_view():\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        let sig = result.symbols[0].signature.as_ref().unwrap();
        assert!(sig.contains("@login_required"), "sig = {}", sig);
        assert!(sig.contains("@admin_only"), "sig = {}", sig);
    }

    #[test]
    fn test_decorated_method_in_class() {
        let result = parse("class Foo:\n    @staticmethod\n    def helper():\n        pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 2);
        assert_eq!(result.symbols[1].name, "helper");
        assert_eq!(result.symbols[1].kind, SymbolKind::Method);
        assert_eq!(result.symbols[1].parent_index, Some(0));
        let sig = result.symbols[1].signature.as_ref().unwrap();
        assert!(sig.contains("@staticmethod"), "sig = {}", sig);
    }

    #[test]
    fn test_module_constant_allcaps() {
        let result = parse("MAX_SIZE = 100\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "MAX_SIZE");
        assert_eq!(result.symbols[0].kind, SymbolKind::Variable);
    }

    #[test]
    fn test_module_constant_typed() {
        let result = parse("config: Config = get_config()\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "config");
        assert_eq!(result.symbols[0].kind, SymbolKind::Variable);
    }

    #[test]
    fn test_non_constant_skipped() {
        let result = parse("result = compute()\n");
        assert!(!result.has_errors);
        assert_eq!(
            result.symbols.len(),
            0,
            "lowercase non-typed assignment should not be extracted"
        );
    }

    #[test]
    fn test_class_level_assignment_skipped() {
        let result = parse("class Foo:\n    MAX = 100\n");
        assert!(!result.has_errors);
        // Only the class itself should be extracted, not the class-level constant
        let names: Vec<&str> = result.symbols.iter().map(|s| s.name.as_str()).collect();
        assert!(names.contains(&"Foo"), "class should be extracted");
        assert!(
            !names.contains(&"MAX"),
            "class-level constant should NOT be extracted, got: {:?}",
            names
        );
    }

    #[test]
    fn test_method_vs_function() {
        let result =
            parse("def top():\n    pass\n\nclass C:\n    def inner(self):\n        pass\n");
        assert!(!result.has_errors);
        let top = result.symbols.iter().find(|s| s.name == "top").unwrap();
        let inner = result.symbols.iter().find(|s| s.name == "inner").unwrap();
        assert_eq!(top.kind, SymbolKind::Function);
        assert_eq!(inner.kind, SymbolKind::Method);
    }

    #[test]
    fn test_empty_file() {
        let result = parse("");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 0);
    }

    #[test]
    fn test_malformed_file() {
        let result = parse("def broken(\n    {}\n");
        assert!(result.has_errors);
    }

    // --- Import extraction ---

    #[test]
    fn test_import_simple() {
        let result = parse("import os\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os");
        assert_eq!(result.imports[0].imported_symbols, vec!["os"]);
    }

    #[test]
    fn test_import_dotted() {
        let result = parse("import os.path\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os.path");
        assert_eq!(result.imports[0].imported_symbols, vec!["path"]);
    }

    #[test]
    fn test_import_aliased() {
        let result = parse("import numpy as np\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "numpy");
        assert_eq!(result.imports[0].imported_symbols, vec!["np"]);
    }

    #[test]
    fn test_from_import() {
        let result = parse("from os import path\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os");
        assert!(
            result.imports[0]
                .imported_symbols
                .contains(&"path".to_string()),
            "imports: {:?}",
            result.imports[0]
        );
    }

    #[test]
    fn test_from_import_multiple() {
        let result = parse("from os.path import join, exists\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os.path");
        assert!(result.imports[0]
            .imported_symbols
            .contains(&"join".to_string()));
        assert!(result.imports[0]
            .imported_symbols
            .contains(&"exists".to_string()));
    }

    #[test]
    fn test_from_import_relative() {
        let result = parse("from . import utils\n");
        assert_eq!(result.imports.len(), 1);
        // The module_name for `from .` is a relative_import node
        assert!(
            result.imports[0]
                .imported_symbols
                .contains(&"utils".to_string()),
            "imports: {:?}",
            result.imports[0]
        );
    }

    #[test]
    fn test_from_import_wildcard() {
        let result = parse("from foo import *\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "foo");
        assert!(
            result.imports[0].imported_symbols.is_empty(),
            "wildcard should have empty imported_symbols"
        );
    }

    // --- Call extraction ---

    #[test]
    fn test_function_call() {
        let result = parse("def main():\n    helper()\n\ndef helper():\n    pass\n");
        let call = result
            .calls
            .iter()
            .find(|c| c.callee_name == "helper")
            .expect("should find call to helper");
        assert_eq!(call.caller_name, "main");
    }

    #[test]
    fn test_method_call() {
        let result = parse("def main():\n    obj.process()\n");
        let call = result
            .calls
            .iter()
            .find(|c| c.callee_name == "process")
            .expect("should find call to process");
        assert_eq!(call.caller_name, "main");
    }

    #[test]
    fn test_chained_method_call() {
        let result = parse("def main():\n    obj.foo().bar()\n");
        let names: Vec<&str> = result
            .calls
            .iter()
            .map(|c| c.callee_name.as_str())
            .collect();
        assert!(names.contains(&"foo"), "calls: {:?}", names);
        assert!(names.contains(&"bar"), "calls: {:?}", names);
    }

    #[test]
    fn test_builtin_call_filtered() {
        let result = parse("def main():\n    print(len(x))\n");
        assert!(
            result.calls.is_empty(),
            "builtin calls should be filtered, got: {:?}",
            result.calls
        );
    }

    // --- Type reference extraction ---

    #[test]
    fn test_type_ref_parameter() {
        let result = parse("def foo(x: Config):\n    pass\n");
        let refs: Vec<&str> = result
            .type_refs
            .iter()
            .map(|r| r.to_type.as_str())
            .collect();
        assert!(
            refs.contains(&"Config"),
            "should find Config type ref, got: {:?}",
            refs
        );
    }

    #[test]
    fn test_type_ref_return() {
        let result = parse("def foo() -> Result:\n    pass\n");
        let refs: Vec<&str> = result
            .type_refs
            .iter()
            .map(|r| r.to_type.as_str())
            .collect();
        assert!(
            refs.contains(&"Result"),
            "should find Result type ref, got: {:?}",
            refs
        );
    }

    #[test]
    fn test_type_ref_assignment() {
        let result = parse("def foo():\n    x: Config = get()\n");
        let refs: Vec<&str> = result
            .type_refs
            .iter()
            .map(|r| r.to_type.as_str())
            .collect();
        assert!(
            refs.contains(&"Config"),
            "should find Config type ref, got: {:?}",
            refs
        );
    }

    #[test]
    fn test_builtin_type_filtered() {
        let result = parse("def foo(x: int, y: str) -> bool:\n    pass\n");
        assert!(
            result.type_refs.is_empty(),
            "builtin types should be filtered, got: {:?}",
            result.type_refs
        );
    }

    // --- Resolver helpers ---

    fn setup_python_project() -> tempfile::TempDir {
        let tmp = tempfile::tempdir().unwrap();
        // foo/
        //   __init__.py
        //   bar.py
        //   utils/
        //     __init__.py
        //     helpers.py
        // src/
        //   app.py
        // main.py
        let foo = tmp.path().join("foo");
        let utils = foo.join("utils");
        let src = tmp.path().join("src");
        std::fs::create_dir_all(&utils).unwrap();
        std::fs::create_dir_all(&src).unwrap();
        std::fs::write(foo.join("__init__.py"), "").unwrap();
        std::fs::write(foo.join("bar.py"), "def greet(): pass").unwrap();
        std::fs::write(utils.join("__init__.py"), "").unwrap();
        std::fs::write(utils.join("helpers.py"), "def help(): pass").unwrap();
        std::fs::write(src.join("app.py"), "def run(): pass").unwrap();
        std::fs::write(tmp.path().join("main.py"), "import foo").unwrap();
        tmp
    }

    // --- Resolver tests ---

    #[test]
    fn test_resolve_absolute_simple() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.bar", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve foo.bar");
        assert!(result.unwrap().ends_with("bar.py"));
    }

    #[test]
    fn test_resolve_absolute_dotted_package() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.utils", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve foo.utils to __init__.py");
        let path = result.unwrap();
        assert!(path.ends_with("__init__.py"));
        assert!(path.to_string_lossy().contains("utils"));
    }

    #[test]
    fn test_resolve_absolute_from_src() {
        let tmp = setup_python_project();
        let result = resolve_python_import("app", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve app from src/ fallback");
        assert!(result.unwrap().ends_with("app.py"));
    }

    #[test]
    fn test_resolve_relative_single_dot() {
        let tmp = setup_python_project();
        let result = resolve_python_import(".bar", "foo/__init__.py", tmp.path());
        assert!(result.is_some(), "should resolve .bar from foo/");
        assert!(result.unwrap().ends_with("bar.py"));
    }

    #[test]
    fn test_resolve_relative_double_dot() {
        let tmp = setup_python_project();
        let result = resolve_python_import("..bar", "foo/utils/helpers.py", tmp.path());
        assert!(result.is_some(), "should resolve ..bar from foo/utils/");
        assert!(result.unwrap().ends_with("bar.py"));
    }

    #[test]
    fn test_resolve_package_init() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve foo to __init__.py");
        assert!(result.unwrap().ends_with("__init__.py"));
    }

    #[test]
    fn test_resolve_external_returns_none() {
        let tmp = setup_python_project();
        let result = resolve_python_import("numpy", "main.py", tmp.path());
        assert!(result.is_none(), "external package should return None");
    }

    #[test]
    fn test_resolve_empty_path() {
        let tmp = setup_python_project();
        let result = resolve_python_import("", "main.py", tmp.path());
        assert!(result.is_none());
    }

    #[test]
    fn test_resolve_relative_dot_init() {
        let tmp = setup_python_project();
        // `from . import utils` inside foo/__init__.py
        std::fs::write(tmp.path().join("foo/__init__.py"), "from . import utils").unwrap();
        let result = resolve_python_import(".utils", "foo/__init__.py", tmp.path());
        assert!(result.is_some(), "should resolve .utils from foo/");
    }

    #[test]
    fn test_resolve_deep_dotted() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.utils.helpers", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve foo.utils.helpers");
        assert!(result.unwrap().ends_with("helpers.py"));
    }

    // --- Additional coverage tests ---

    #[test]
    fn test_decorated_class() {
        let result = parse(
            "@dataclass\nclass Config:\n    name: str\n    def validate(self):\n        pass\n",
        );
        assert!(!result.has_errors);
        let config = result.symbols.iter().find(|s| s.name == "Config");
        assert!(config.is_some(), "decorated class should be extracted");
        assert_eq!(config.unwrap().kind, SymbolKind::Class);
        let sig = config.unwrap().signature.as_ref().unwrap();
        assert!(
            sig.contains("@dataclass"),
            "sig should contain decorator: {}",
            sig
        );
        assert!(
            sig.contains("class Config"),
            "sig should contain class def: {}",
            sig
        );
        // Method inside decorated class should also be extracted
        let validate = result.symbols.iter().find(|s| s.name == "validate");
        assert!(
            validate.is_some(),
            "method in decorated class should be extracted"
        );
        assert_eq!(validate.unwrap().kind, SymbolKind::Method);
    }

    #[test]
    fn test_decorated_class_with_methods_parent_index() {
        let result = parse("@decorator\nclass Svc:\n    def run(self):\n        pass\n    def stop(self):\n        pass\n");
        assert!(!result.has_errors);
        let svc = result.symbols.iter().find(|s| s.name == "Svc").unwrap();
        assert_eq!(svc.kind, SymbolKind::Class);
        let svc_idx = result.symbols.iter().position(|s| s.name == "Svc").unwrap();
        for method in result
            .symbols
            .iter()
            .filter(|s| s.kind == SymbolKind::Method)
        {
            assert_eq!(
                method.parent_index,
                Some(svc_idx),
                "method '{}' should have Svc as parent",
                method.name
            );
        }
    }

    #[test]
    fn test_resolve_relative_dot_only_to_init() {
        // `from . import x` => resolves to __init__.py
        let tmp = setup_python_project();
        let result = resolve_python_import(".", "foo/bar.py", tmp.path());
        assert!(
            result.is_some(),
            "bare dot should resolve to __init__.py in foo/"
        );
        assert!(result.unwrap().ends_with("__init__.py"));
    }

    #[test]
    fn test_resolve_relative_dot_only_no_init() {
        // `from . import x` where there is no __init__.py
        let tmp = tempfile::tempdir().unwrap();
        let pkg = tmp.path().join("pkg");
        std::fs::create_dir_all(&pkg).unwrap();
        std::fs::write(pkg.join("mod.py"), "").unwrap();
        // No __init__.py in pkg/
        let result = resolve_python_import(".", "pkg/mod.py", tmp.path());
        assert!(
            result.is_none(),
            "bare dot without __init__.py should return None"
        );
    }

    #[test]
    fn test_resolve_module_path_empty_parts() {
        // resolve_module_path with empty parts => tries __init__.py
        let tmp = tempfile::tempdir().unwrap();
        let pkg = tmp.path().join("pkg");
        std::fs::create_dir_all(&pkg).unwrap();
        std::fs::write(pkg.join("__init__.py"), "").unwrap();
        let result = resolve_module_path(&[], &pkg);
        assert!(
            result.is_some(),
            "empty parts with __init__.py should resolve"
        );
        assert!(result.unwrap().ends_with("__init__.py"));
    }

    #[test]
    fn test_resolve_module_path_empty_parts_no_init() {
        let tmp = tempfile::tempdir().unwrap();
        let pkg = tmp.path().join("pkg");
        std::fs::create_dir_all(&pkg).unwrap();
        let result = resolve_module_path(&[], &pkg);
        assert!(
            result.is_none(),
            "empty parts without __init__.py should return None"
        );
    }

    #[test]
    fn test_resolve_intermediate_not_dir() {
        // import path with intermediate part that is not a directory
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.bar.nonexistent", "main.py", tmp.path());
        assert!(result.is_none(), "intermediate non-directory should fail");
    }

    #[test]
    fn test_import_aliased_from() {
        // from os import path as p
        let result = parse("from os import path as p\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os");
        assert!(
            result.imports[0]
                .imported_symbols
                .contains(&"p".to_string()),
            "aliased import should use alias name: {:?}",
            result.imports[0].imported_symbols
        );
    }

    #[test]
    fn test_import_from_aliased_without_alias() {
        // from os import path (no alias)
        let result = parse("from os.path import join, exists\n");
        assert_eq!(result.imports.len(), 1);
        assert!(result.imports[0]
            .imported_symbols
            .contains(&"join".to_string()));
        assert!(result.imports[0]
            .imported_symbols
            .contains(&"exists".to_string()));
    }

    #[test]
    fn test_multiple_plain_imports() {
        let result = parse("import os\nimport sys\nimport json\n");
        assert_eq!(result.imports.len(), 3);
        let paths: Vec<&str> = result.imports.iter().map(|i| i.path.as_str()).collect();
        assert!(paths.contains(&"os"));
        assert!(paths.contains(&"sys"));
        assert!(paths.contains(&"json"));
    }

    #[test]
    fn test_triple_dot_relative_import() {
        let tmp = tempfile::tempdir().unwrap();
        let deep = tmp.path().join("a").join("b").join("c");
        std::fs::create_dir_all(&deep).unwrap();
        std::fs::write(deep.join("mod.py"), "").unwrap();
        std::fs::write(tmp.path().join("a").join("target.py"), "").unwrap();
        let result = resolve_python_import("...target", "a/b/c/mod.py", tmp.path());
        assert!(result.is_some(), "triple dot should resolve two levels up");
        assert!(result.unwrap().ends_with("target.py"));
    }

    #[test]
    fn test_resolve_nonexistent_module() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.nonexistent", "main.py", tmp.path());
        assert!(result.is_none(), "nonexistent module should return None");
    }

    #[test]
    fn test_call_with_attribute_access() {
        // Test the "attribute" branch in collect_calls
        let result = parse("def main():\n    config.get_value()\n");
        let calls: Vec<&str> = result
            .calls
            .iter()
            .map(|c| c.callee_name.as_str())
            .collect();
        assert!(
            calls.contains(&"get_value"),
            "should extract attribute call: {:?}",
            calls
        );
    }

    #[test]
    fn test_type_ref_builtin_type_not_extracted() {
        // All builtin types should be filtered
        let result = parse("def foo(x: int, y: str, z: list) -> bool:\n    pass\n");
        assert!(
            result.type_refs.is_empty(),
            "builtin types should be filtered: {:?}",
            result.type_refs
        );
    }

    #[test]
    fn test_resolve_from_lib_directory() {
        // Test resolution from "lib" source directory fallback
        let tmp = tempfile::tempdir().unwrap();
        let lib = tmp.path().join("lib");
        std::fs::create_dir_all(&lib).unwrap();
        std::fs::write(lib.join("mymod.py"), "").unwrap();
        let result = resolve_python_import("mymod", "main.py", tmp.path());
        assert!(result.is_some(), "should resolve from lib/ fallback");
        assert!(result.unwrap().ends_with("mymod.py"));
    }

    #[test]
    fn test_expression_statement_not_assignment() {
        // expression_statement with non-assignment child at module level
        let result = parse("print('hello')\n");
        assert!(!result.has_errors);
        assert_eq!(
            result.symbols.len(),
            0,
            "bare expression should not produce symbols"
        );
    }

    #[test]
    fn test_assignment_left_not_identifier() {
        // Tuple unpacking at module level - left side is not a simple identifier
        let result = parse("x, y = 1, 2\n");
        assert!(!result.has_errors);
        // Should not crash; tuple assignment's left is not identifier
    }

    #[test]
    fn test_is_python_builtin_positive() {
        assert!(is_python_builtin("print"));
        assert!(is_python_builtin("len"));
        assert!(is_python_builtin("isinstance"));
        assert!(is_python_builtin("ValueError"));
        assert!(is_python_builtin("super"));
        assert!(is_python_builtin("object"));
    }

    #[test]
    fn test_is_python_builtin_negative() {
        assert!(!is_python_builtin("my_function"));
        assert!(!is_python_builtin("CustomError"));
        assert!(!is_python_builtin(""));
    }

    #[test]
    fn test_is_python_builtin_type_positive() {
        assert!(is_python_builtin_type("int"));
        assert!(is_python_builtin_type("str"));
        assert!(is_python_builtin_type("Optional"));
        assert!(is_python_builtin_type("List"));
        assert!(is_python_builtin_type("TypeVar"));
        assert!(is_python_builtin_type("Self"));
        assert!(is_python_builtin_type("Never"));
        assert!(is_python_builtin_type("NoReturn"));
    }

    #[test]
    fn test_is_python_builtin_type_negative() {
        assert!(!is_python_builtin_type("MyClass"));
        assert!(!is_python_builtin_type("AppConfig"));
        assert!(!is_python_builtin_type(""));
    }

    #[test]
    fn test_type_ref_inside_class_method() {
        let result =
            parse("class Svc:\n    def process(self, cfg: AppConfig) -> Response:\n        pass\n");
        assert!(!result.has_errors);
        let ref_types: Vec<&str> = result
            .type_refs
            .iter()
            .map(|r| r.to_type.as_str())
            .collect();
        assert!(
            ref_types.contains(&"AppConfig"),
            "should find AppConfig type ref: {:?}",
            ref_types
        );
        assert!(
            ref_types.contains(&"Response"),
            "should find Response type ref: {:?}",
            ref_types
        );
    }

    #[test]
    fn test_module_constant_underscore_allcaps() {
        let result = parse("MAX_RETRY_COUNT = 3\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "MAX_RETRY_COUNT");
        assert_eq!(result.symbols[0].kind, SymbolKind::Variable);
    }

    #[test]
    fn test_resolve_absolute_nonexistent_package() {
        let tmp = setup_python_project();
        let result = resolve_python_import("totally_missing.submod", "main.py", tmp.path());
        assert!(result.is_none());
    }

    #[test]
    fn test_resolve_relative_too_many_dots() {
        let tmp = tempfile::tempdir().unwrap();
        let pkg = tmp.path().join("a");
        std::fs::create_dir_all(&pkg).unwrap();
        std::fs::write(pkg.join("mod.py"), "").unwrap();
        let result = resolve_python_import("....target", "a/mod.py", tmp.path());
        assert!(result.is_none(), "too many dots should return None");
    }

    #[test]
    fn test_import_plain_multiple_dotted_names() {
        // import os, sys, json — each should produce a separate import
        let result = parse("import os, sys, json\n");
        assert!(!result.has_errors);
        let paths: Vec<&str> = result.imports.iter().map(|i| i.path.as_str()).collect();
        assert!(paths.contains(&"os"), "imports: {:?}", paths);
        assert!(paths.contains(&"sys"), "imports: {:?}", paths);
        assert!(paths.contains(&"json"), "imports: {:?}", paths);
    }

    #[test]
    fn test_from_import_with_alias() {
        let result = parse("from os import path as p\n");
        assert_eq!(result.imports.len(), 1);
        assert_eq!(result.imports[0].path, "os");
        assert!(
            result.imports[0]
                .imported_symbols
                .contains(&"p".to_string()),
            "aliased import should use alias name: {:?}",
            result.imports[0].imported_symbols
        );
    }

    #[test]
    fn test_call_identifier_branch() {
        // Direct function call (identifier branch in collect_calls)
        let result = parse("def main():\n    do_work()\n");
        assert!(!result.has_errors);
        let calls: Vec<&str> = result
            .calls
            .iter()
            .map(|c| c.callee_name.as_str())
            .collect();
        assert!(
            calls.contains(&"do_work"),
            "should capture identifier call: {:?}",
            calls
        );
    }

    #[test]
    fn test_decorated_definition_no_definition_node() {
        // A decorated definition where only the decorator is present
        // In valid Python this won't happen, but we test robustness
        // Use a valid pattern: decorated function
        let result = parse("@property\ndef x(self):\n    return 1\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "x");
    }

    // ── Additional edge case tests ──

    #[test]
    fn test_class_with_inheritance() {
        let result = parse("class Child(Parent):\n    def method(self):\n        pass\n");
        assert!(!result.has_errors);
        let child = result.symbols.iter().find(|s| s.name == "Child").unwrap();
        assert_eq!(child.kind, SymbolKind::Class);
        let sig = child.signature.as_ref().unwrap();
        assert!(
            sig.contains("Parent"),
            "sig should contain base class: {}",
            sig
        );
    }

    #[test]
    fn test_class_multiple_inheritance() {
        let result = parse("class Multi(Base1, Base2, Mixin):\n    pass\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "Multi");
        let sig = result.symbols[0].signature.as_ref().unwrap();
        assert!(sig.contains("Base1"), "sig = {}", sig);
        assert!(sig.contains("Mixin"), "sig = {}", sig);
    }

    #[test]
    fn test_property_decorated_method() {
        let result =
            parse("class Foo:\n    @property\n    def name(self):\n        return self._name\n");
        assert!(!result.has_errors);
        let name_method = result.symbols.iter().find(|s| s.name == "name").unwrap();
        assert_eq!(name_method.kind, SymbolKind::Method);
        let sig = name_method.signature.as_ref().unwrap();
        assert!(sig.contains("@property"), "sig = {}", sig);
    }

    #[test]
    fn test_classmethod_decorated() {
        let result = parse("class Foo:\n    @classmethod\n    def create(cls):\n        pass\n");
        assert!(!result.has_errors);
        let create = result.symbols.iter().find(|s| s.name == "create").unwrap();
        assert_eq!(create.kind, SymbolKind::Method);
        let sig = create.signature.as_ref().unwrap();
        assert!(sig.contains("@classmethod"), "sig = {}", sig);
    }

    #[test]
    fn test_function_with_complex_signature() {
        let result = parse(
            "def process(items: list[str], *, timeout: int = 30) -> dict[str, Any]:\n    pass\n",
        );
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "process");
        let sig = result.symbols[0].signature.as_ref().unwrap();
        assert!(sig.contains("def process"), "sig = {}", sig);
    }

    #[test]
    fn test_call_inside_method() {
        let result =
            parse("class Svc:\n    def run(self):\n        self.setup()\n        process()\n");
        let calls: Vec<&str> = result
            .calls
            .iter()
            .map(|c| c.callee_name.as_str())
            .collect();
        assert!(
            calls.contains(&"setup"),
            "should find self.setup(): {:?}",
            calls
        );
        assert!(
            calls.contains(&"process"),
            "should find process(): {:?}",
            calls
        );
    }

    #[test]
    fn test_type_ref_generic_annotation() {
        let result = parse("def foo(items: List[Config]) -> Optional[Response]:\n    pass\n");
        let refs: Vec<&str> = result
            .type_refs
            .iter()
            .map(|r| r.to_type.as_str())
            .collect();
        assert!(refs.contains(&"Config"), "type_refs: {:?}", refs);
        assert!(refs.contains(&"Response"), "type_refs: {:?}", refs);
    }

    #[test]
    fn test_multiple_functions_and_classes() {
        let result = parse(
            "def a():\n    pass\ndef b():\n    pass\nclass C:\n    def d(self):\n        pass\n",
        );
        assert!(!result.has_errors);
        let names: Vec<&str> = result.symbols.iter().map(|s| s.name.as_str()).collect();
        assert_eq!(names, vec!["a", "b", "C", "d"]);
    }

    #[test]
    fn test_module_constant_with_numbers_not_extracted() {
        // digits are not uppercase letters, so the allcaps check fails
        let result = parse("MAX_SIZE_3 = 1024\n");
        assert!(!result.has_errors);
        assert_eq!(
            result.symbols.len(),
            0,
            "allcaps with digits should NOT be extracted (digits fail the check)"
        );
    }

    #[test]
    fn test_module_constant_pure_allcaps() {
        let result = parse("MAX_SIZE = 1024\n");
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "MAX_SIZE");
    }

    #[test]
    fn test_from_import_relative_double_dot() {
        let result = parse("from .. import utils\n");
        assert!(!result.has_errors);
        assert_eq!(result.imports.len(), 1);
        assert!(result.imports[0]
            .imported_symbols
            .contains(&"utils".to_string()));
    }

    #[test]
    fn test_language_parser_trait_name() {
        let parser = PythonParser;
        assert_eq!(parser.language_name(), "python");
    }

    #[test]
    fn test_language_parser_parse_via_trait() {
        let parser = PythonParser;
        let result = parser.parse("def foo():\n    pass\n", &PathBuf::from("test.py"));
        assert!(!result.has_errors);
        assert_eq!(result.symbols.len(), 1);
        assert_eq!(result.symbols[0].name, "foo");
    }

    #[test]
    fn test_resolve_from_init_subpackage() {
        let tmp = setup_python_project();
        let result = resolve_python_import("foo.utils.helpers", "foo/__init__.py", tmp.path());
        assert!(result.is_some(), "should resolve deep submodule from init");
        assert!(result.unwrap().ends_with("helpers.py"));
    }

    #[test]
    fn test_call_nested_in_class_method() {
        let result =
            parse("class A:\n    def m(self):\n        x = helper()\n        y = other()\n");
        let callers: Vec<&str> = result
            .calls
            .iter()
            .map(|c| c.caller_name.as_str())
            .collect();
        // All calls inside method m should have "m" as caller
        for caller in &callers {
            assert_eq!(*caller, "m");
        }
    }
}