code_moniker_core/lang/python/

mod.rs

use tree_sitter::{Language, Parser, Tree};

use crate::core::code_graph::CodeGraph;
use crate::core::moniker::Moniker;
use crate::core::shape::Shape;

use crate::lang::KindSpec;

pub mod build;
mod canonicalize;
mod kinds;
mod sdk_pipeline;

#[derive(Clone, Debug, Default)]
pub struct Presets {}

pub fn parse(source: &str) -> Tree {
	let mut parser = Parser::new();
	let language: Language = tree_sitter_python::LANGUAGE.into();
	parser.set_language(&language).unwrap_or_else(|err| {
		panic!("failed to load tree-sitter Python grammar: {err}");
	});
	parser.parse(source, None).unwrap_or_else(|| {
		panic!("tree-sitter parse returned None on a non-cancelled call");
	})
}

pub fn extract(
	uri: &str,
	source: &str,
	anchor: &Moniker,
	deep: bool,
	presets: &Presets,
) -> CodeGraph {
	sdk_pipeline::extract(uri, source, anchor, deep, presets)
}

pub struct Lang;

const DEF_KINDS: &[&str] = &[
	"class",
	"type",
	"function",
	"method",
	"async_function",
	"path",
];

const DEF_KIND_SPECS: &[KindSpec] = &[
	KindSpec::new("class", Shape::Type, 20, "class"),
	KindSpec::new("type", Shape::Type, 21, "type"),
	KindSpec::new("function", Shape::Callable, 40, "function"),
	KindSpec::new("async_function", Shape::Callable, 41, "async_function"),
	KindSpec::new("method", Shape::Callable, 42, "method"),
	KindSpec::new("path", Shape::Value, 63, "path"),
];

impl crate::lang::LangExtractor for Lang {
	type Presets = Presets;
	const LANG_TAG: &'static str = "python";
	const ALLOWED_KINDS: &'static [&'static str] = DEF_KINDS;
	const KIND_SPECS: &'static [KindSpec] = DEF_KIND_SPECS;
	const ALLOWED_VISIBILITIES: &'static [&'static str] = &["public", "private", "module"];

	fn extract(
		uri: &str,
		source: &str,
		anchor: &Moniker,
		deep: bool,
		presets: &Self::Presets,
	) -> CodeGraph {
		extract(uri, source, anchor, deep, presets)
	}
}

pub fn builtin_external_root(root: &str) -> bool {
	root == "builtins" || sdk_pipeline::STDLIB_PACKAGES.binary_search(&root).is_ok()
}

#[cfg(test)]
mod tests {
	use super::*;
	use crate::core::moniker::MonikerBuilder;
	use crate::lang::assert_conformance;

	fn make_anchor() -> Moniker {
		MonikerBuilder::new().project(b"app").build()
	}

	fn extract_default(uri: &str, source: &str, anchor: &Moniker, deep: bool) -> CodeGraph {
		let g = extract(uri, source, anchor, deep, &Presets::default());
		assert_conformance::<super::Lang>(&g, anchor);
		g
	}

	#[test]
	fn parse_empty_returns_module() {
		let tree = parse("");
		assert_eq!(tree.root_node().kind(), "module");
	}

	#[test]
	fn extract_module_uses_path_segments() {
		let g = extract_default("acme/util/text.py", "", &make_anchor(), false);
		let expected = MonikerBuilder::new()
			.project(b"app")
			.segment(b"lang", b"python")
			.segment(b"package", b"acme")
			.segment(b"package", b"util")
			.segment(b"module", b"text")
			.build();
		assert_eq!(g.root(), &expected);
	}

	#[test]
	fn extract_module_root_is_filename_only() {
		let g = extract_default("foo.py", "", &make_anchor(), false);
		let expected = MonikerBuilder::new()
			.project(b"app")
			.segment(b"lang", b"python")
			.segment(b"module", b"foo")
			.build();
		assert_eq!(g.root(), &expected);
	}

	#[test]
	fn extract_function_with_typed_params_emits_full_signature() {
		let src = "def make(x: int, y: str) -> int:\n    return x\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let f = g
			.defs()
			.find(|d| d.kind == b"function")
			.expect("function def");
		let last = f.moniker.as_view().segments().last().unwrap();
		assert_eq!(last.kind, b"function");
		assert_eq!(last.name, b"make(x:int,y:str)");
		assert_eq!(f.signature, b"x:int,y:str".to_vec());
	}

	#[test]
	fn extract_function_with_untyped_params_uses_name_only_slots() {
		let src = "def f(a, b=1):\n    return a\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let f = g
			.defs()
			.find(|d| d.kind == b"function")
			.expect("function def");
		let last = f.moniker.as_view().segments().last().unwrap();
		assert_eq!(last.name, b"f(a,b)");
		assert_eq!(f.signature, b"a,b".to_vec());
	}

	#[test]
	fn extract_classmethod_excludes_cls_from_signature() {
		let src = "class Foo:\n    @classmethod\n    def make(cls, x: int) -> 'Foo':\n        return cls()\n";
		let g = extract_default("foo.py", src, &make_anchor(), false);
		let m = g.defs().find(|d| d.kind == b"method").expect("method def");
		assert_eq!(
			m.moniker.as_view().segments().last().unwrap().name,
			b"make(x:int)"
		);
	}

	#[test]
	fn extract_double_underscore_visibility_is_private() {
		let src = "class Foo:\n    def __secret(self):\n        pass\n";
		let g = extract_default("foo.py", src, &make_anchor(), false);
		let m = g.defs().find(|d| d.kind == b"method").expect("method def");
		assert_eq!(m.visibility, b"private".to_vec());
	}

	#[test]
	fn extract_single_underscore_visibility_is_module() {
		let src = "def _internal():\n    pass\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let f = g
			.defs()
			.find(|d| d.kind == b"function")
			.expect("function def");
		assert_eq!(f.visibility, b"module".to_vec());
	}

	#[test]
	fn extract_import_module_emits_imports_module() {
		let src = "import os\nimport acme.util as u\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let kinds: Vec<&[u8]> = g.refs().map(|r| r.kind.as_ref()).collect();
		assert_eq!(kinds.iter().filter(|k| **k == b"imports_module").count(), 2);
	}

	#[test]
	fn extract_stdlib_import_marks_external() {
		let g = extract_default("m.py", "import json\n", &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"imports_module")
			.expect("imports_module");
		assert_eq!(r.confidence, b"external".to_vec());
	}

	#[test]
	fn extract_project_import_marks_imported() {
		let g = extract_default("m.py", "import acme.util\n", &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"imports_module")
			.expect("imports_module");
		assert_eq!(r.confidence, b"imported".to_vec());
	}

	#[test]
	fn extract_from_import_emits_one_imports_symbol_per_name() {
		let src = "from acme.util import a, b as c\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let names: Vec<&[u8]> = g
			.refs()
			.filter(|r| r.kind == b"imports_symbol")
			.map(|r| r.target.as_view().segments().last().unwrap().name)
			.collect();
		assert_eq!(names, vec![&b"a"[..], &b"b"[..]]);
		let segs: Vec<_> = g
			.refs()
			.find(|r| r.kind == b"imports_symbol")
			.unwrap()
			.target
			.as_view()
			.segments()
			.collect();
		let kinds: Vec<&[u8]> = segs.iter().map(|s| s.kind).collect();
		assert_eq!(
			kinds,
			vec![&b"lang"[..], &b"package"[..], &b"module"[..], &b"path"[..]]
		);
		let aliased = g
			.refs()
			.find(|r| r.kind == b"imports_symbol" && r.alias == b"c")
			.expect("aliased import");
		assert_eq!(aliased.alias, b"c".to_vec());
	}

	#[test]
	fn extract_relative_import_resolves_against_importer() {
		let src = "from .util import helper\n";
		let g = extract_default("acme/m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"imports_symbol")
			.expect("imports_symbol");
		let segs: Vec<_> = r.target.as_view().segments().collect();
		let kinds: Vec<&[u8]> = segs.iter().map(|s| s.kind).collect();
		let names: Vec<&[u8]> = segs.iter().map(|s| s.name).collect();
		assert_eq!(
			kinds,
			vec![&b"lang"[..], &b"package"[..], &b"module"[..], &b"path"[..]]
		);
		assert_eq!(
			names,
			vec![&b"python"[..], &b"acme"[..], &b"util"[..], &b"helper"[..]]
		);
	}

	#[test]
	fn extract_relative_import_underflow_falls_back_to_external_pkg() {
		let src = "from ...foo import bar\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"imports_symbol")
			.expect("imports_symbol");
		let segs: Vec<_> = r.target.as_view().segments().collect();
		assert_eq!(segs[0].kind, b"external_pkg");
		assert_eq!(segs[0].name, b"...");
	}

	#[test]
	fn extract_decorator_emits_annotates() {
		let src = "import functools\n@functools.wraps(fn)\ndef g():\n    pass\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let ann = g
			.refs()
			.find(|r| r.kind == b"annotates")
			.expect("annotates ref");
		assert_eq!(
			ann.target.as_view().segments().last().unwrap().name,
			b"wraps"
		);
	}

	#[test]
	fn extract_param_read_marks_confidence_local() {
		let src = "def f(x):\n    return x\n";
		let g = extract_default("m.py", src, &make_anchor(), true);
		let r = g
			.refs()
			.find(|r| {
				r.kind == b"reads" && r.target.as_view().segments().last().unwrap().name == b"x"
			})
			.expect("reads x");
		assert_eq!(r.confidence, b"local".to_vec());
	}

	#[test]
	fn extract_deep_emits_param_def() {
		let src = "def f(x, y: int):\n    return x\n";
		let g = extract_default("m.py", src, &make_anchor(), true);
		let params: Vec<&[u8]> = g
			.defs()
			.filter(|d| d.kind == b"param")
			.map(|d| d.moniker.as_view().segments().last().unwrap().name)
			.collect();
		assert!(params.contains(&&b"x"[..]));
		assert!(params.contains(&&b"y"[..]));
	}

	#[test]
	fn extract_async_function_tracks_local_assignments() {
		let src = "async def f():\n    x = 1\n    return x\n";
		let g = extract_default("m.py", src, &make_anchor(), true);
		let r = g
			.refs()
			.find(|r| {
				r.kind == b"reads" && r.target.as_view().segments().last().unwrap().name == b"x"
			})
			.expect("reads x");
		assert_eq!(r.confidence, b"local".to_vec());
	}

	#[test]
	fn extract_imported_identifier_read_targets_import_moniker() {
		let src = "import asyncio\nasync def f():\n    return asyncio\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"reads" && r.confidence == b"external")
			.expect("external read");
		let segs: Vec<_> = r.target.as_view().segments().collect();
		assert_eq!(segs[0].kind, b"external_pkg");
		assert_eq!(segs[0].name, b"asyncio");
	}

	#[test]
	fn extract_self_member_call_resolves_via_typed_constructor_param() {
		let src = "class Store:\n    def reserve(self) -> None:\n        pass\n\nclass Worker:\n    def __init__(self, store: Store) -> None:\n        self._store = store\n\n    def run(self) -> None:\n        self._store.reserve()\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| {
				r.kind == b"method_call"
					&& r.target.as_view().segments().last().unwrap().name == b"reserve()"
			})
			.expect("method_call Store.reserve");
		assert_eq!(r.confidence, b"resolved".to_vec());
		let parent = r.target.parent().expect("method parent");
		assert_eq!(parent.as_view().segments().last().unwrap().name, b"Store");
	}

	#[test]
	fn extract_self_member_call_uses_constructor_type_independent_of_method_order() {
		let src = "class Store:\n    def reserve(self) -> None:\n        pass\n\nclass Other:\n    def reserve(self) -> None:\n        pass\n\nclass Worker:\n    def before_init(self) -> None:\n        self._store.reserve()\n\n    def __init__(self, store: Store) -> None:\n        self._store = store\n\n    def retarget(self, other: Other) -> None:\n        self._store = other\n\n    def after_retarget(self) -> None:\n        self._store.reserve()\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let targets: Vec<Moniker> = g
			.refs()
			.filter(|r| {
				r.kind == b"method_call"
					&& r.target.as_view().segments().last().unwrap().name == b"reserve()"
			})
			.map(|r| r.target.clone())
			.collect();
		assert_eq!(targets.len(), 2);
		for target in targets {
			let parent = target.parent().expect("method parent");
			assert_eq!(parent.as_view().segments().last().unwrap().name, b"Store");
		}
	}

	#[test]
	fn extract_self_callable_attr_call_targets_attribute_type_alias() {
		let src = "from collections.abc import Callable\nfrom typing import TypeAlias\n\nCallback: TypeAlias = Callable[[], None]\n\nclass Worker:\n    def __init__(self, cb: Callback) -> None:\n        self._cb = cb\n\n    def run(self) -> None:\n        self._cb()\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| {
				r.kind == b"calls"
					&& r.target.as_view().segments().last().unwrap().name == b"Callback"
			})
			.expect("calls Callback type alias");
		assert_eq!(r.confidence, b"resolved".to_vec());
		assert!(!g.refs().any(|r| {
			r.kind == b"method_call" && r.target.as_view().segments().last().unwrap().name == b"_cb"
		}));
	}

	#[test]
	fn extract_type_alias_emits_type_def_and_rhs_uses_type() {
		let src = "from typing import TypeAlias\n\nclass User:\n    pass\n\nUserMap: TypeAlias = dict[str, User]\ntype UserResult = User | None\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let type_names: Vec<&[u8]> = g
			.defs()
			.filter(|d| d.kind == b"type")
			.map(|d| d.moniker.as_view().segments().last().unwrap().name)
			.collect();
		assert!(type_names.contains(&&b"UserMap"[..]));
		assert!(type_names.contains(&&b"UserResult"[..]));
		assert!(g.refs().any(|r| {
			r.kind == b"uses_type"
				&& r.target.as_view().segments().last().unwrap().name == b"User"
				&& r.confidence == b"resolved"
		}));
		assert!(!g.refs().any(|r| {
			r.kind == b"uses_type"
				&& matches!(
					r.target.as_view().segments().last().unwrap().name,
					b"dict" | b"str" | b"None"
				)
		}));
	}

	#[test]
	fn extract_local_class_call_emits_instantiates() {
		let src = "class User:\n    pass\n\ndef make() -> User:\n    return User()\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"instantiates")
			.expect("instantiates User");
		assert_eq!(r.confidence, b"resolved".to_vec());
		assert_eq!(r.target.as_view().segments().last().unwrap().name, b"User");
	}

	#[test]
	fn extract_local_class_call_prefers_function_scoped_type() {
		let src = "class Local:\n    pass\n\ndef make():\n    class Local:\n        pass\n    return Local()\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let r = g
			.refs()
			.find(|r| r.kind == b"instantiates")
			.expect("instantiates local Local");
		let target_last = r.target.as_view().segments().last().unwrap();
		assert_eq!(target_last.kind, b"class");
		assert_eq!(target_last.name, b"Local");
		let parent = r.target.parent().expect("class parent");
		let parent_last = parent.as_view().segments().last().unwrap();
		assert_eq!(parent_last.kind, b"function");
		assert_eq!(parent_last.name, b"make()");
	}

	#[test]
	fn extract_keyword_argument_names_are_not_reads() {
		let src = "def save(value):\n    return dict(id=value)\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		assert!(!g.refs().any(|r| {
			r.kind == b"reads" && r.target.as_view().segments().last().unwrap().name == b"id"
		}));
	}

	#[test]
	fn extract_attribute_tail_is_not_a_bare_read() {
		let src = "def f(payment):\n    return payment.id\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		assert!(!g.refs().any(|r| {
			r.kind == b"reads" && r.target.as_view().segments().last().unwrap().name == b"id"
		}));
	}

	#[test]
	fn extract_function_docstring_emits_comment_def_parented_on_function() {
		let src = "def f():\n    \"\"\"docstring\"\"\"\n    return 0\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		let fn_moniker = MonikerBuilder::new()
			.project(b"app")
			.segment(b"lang", b"python")
			.segment(b"module", b"m")
			.segment(b"function", b"f()")
			.build();
		let docstring_count = g
			.defs()
			.filter(|d| d.kind == b"comment")
			.filter(|d| {
				d.parent
					.and_then(|i| g.defs().nth(i))
					.is_some_and(|p| p.moniker == fn_moniker)
			})
			.count();
		assert_eq!(
			docstring_count,
			1,
			"function docstring must emit one comment def parented on the function. defs: {:?}",
			g.def_monikers()
		);
	}

	#[test]
	fn extract_class_and_module_docstring_each_emit_one_comment() {
		let src = "\"\"\"module doc\"\"\"\nclass A:\n    \"\"\"class doc\"\"\"\n    pass\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		assert_eq!(
			g.defs().filter(|d| d.kind == b"comment").count(),
			2,
			"module-level and class docstrings should each yield one comment def. defs: {:?}",
			g.def_monikers()
		);
	}

	#[test]
	fn extract_non_docstring_string_at_start_is_not_a_comment() {
		let src = "x = \"hello\"\n";
		let g = extract_default("m.py", src, &make_anchor(), false);
		assert_eq!(
			g.defs().filter(|d| d.kind == b"comment").count(),
			0,
			"string literals that aren't bare expression-statement-strings must NOT be treated as docstrings"
		);
	}
}