luaur-ast 0.1.0

//! Inline port of `luau/tests/AstVisitor.test.cpp` (`TEST_SUITE("AstVisitorTest")`).
//! Verifies the parser + AST visitor traversal end to end: a tracking visitor
//! records every node it's offered, and the tests assert the exact node
//! sequence (and RTTI class) for parsed snippets.
//!
//! Two visitor variants mirror the C++ fixtures:
//! - `Tracking` overrides only the base node hook, so it never descends into
//!   type annotations (the trait's `visit_type` defaults to `false`).
//! - `TrackingWiths` also records/descends types (C++ `AstTypeVisitorTrackingWiths`).

#![cfg(test)]

use core::ffi::c_void;

use crate::records::allocator::Allocator;
use crate::records::ast_name_table::AstNameTable;
use crate::records::ast_node::AstNode;
use crate::records::ast_stat_block::AstStatBlock;
use crate::records::ast_visitor::AstVisitor;
use crate::records::parse_options::ParseOptions;
use crate::records::parser::Parser;
use crate::rtti::AstNodeClass;
use crate::visit::AstVisitable;

use crate::records::ast_expr_constant_number::AstExprConstantNumber;
use crate::records::ast_stat_local::AstStatLocal;
use crate::records::ast_type_reference::AstTypeReference;

#[derive(Default)]
struct Tracking {
    nodes: Vec<*mut c_void>,
}

impl AstVisitor for Tracking {
    fn visit_node(&mut self, node: *mut c_void) -> bool {
        self.nodes.push(node);
        true
    }
}

#[derive(Default)]
struct TrackingWiths {
    nodes: Vec<*mut c_void>,
}

impl AstVisitor for TrackingWiths {
    fn visit_node(&mut self, node: *mut c_void) -> bool {
        self.nodes.push(node);
        true
    }
    fn visit_type(&mut self, node: *mut c_void) -> bool {
        self.nodes.push(node);
        true
    }
}

/// `*mut c_void` AST node -> does it have RTTI class `T`? Every node embeds
/// `AstNode` at offset 0 (the `base` chain), so the cast is sound.
fn is<T: AstNodeClass>(node: *mut c_void) -> bool {
    unsafe { (*(node as *mut AstNode)).is::<T>() }
}

/// Parse `src` (requiring no errors) and hand the root block to `f`.
fn with_block(src: &str, f: impl FnOnce(*mut AstStatBlock)) {
    let mut allocator = Allocator::allocator();
    let mut names = AstNameTable::new(&mut allocator);
    let result = Parser::parse(
        src,
        src.len(),
        &mut names,
        &mut allocator,
        ParseOptions::default(),
    );
    assert!(
        result.errors.is_empty(),
        "unexpected parse errors: {}",
        result.errors.len()
    );
    f(result.root);
}

#[test]
fn type_annotations_are_not_visited() {
    with_block("local a: A<number>\n", |block| {
        let mut v = Tracking::default();
        unsafe { (*block).visit(&mut v) };
        // Only the block and the local — the annotation and its type argument
        // are NOT visited (visit_type defaults to false).
        assert!(is::<AstStatBlock>(v.nodes[0]));
        assert!(is::<AstStatLocal>(v.nodes[1]));
        assert_eq!(v.nodes.len(), 2);
    });
}

#[test]
fn local_two_bindings() {
    with_block("local a, b\n", |block| {
        let mut v = Tracking::default();
        unsafe { (*block).visit(&mut v) };
        assert!(is::<AstStatBlock>(v.nodes[0]));
        assert!(is::<AstStatLocal>(v.nodes[1]));
        assert_eq!(v.nodes.len(), 2);
    });
}

#[test]
fn local_two_annotated_bindings() {
    with_block("local a: A, b: B<number>\n", |block| {
        let mut v = TrackingWiths::default();
        unsafe { (*block).visit(&mut v) };
        assert!(is::<AstStatBlock>(v.nodes[0]));
        assert!(is::<AstStatLocal>(v.nodes[1]));
        assert!(is::<AstTypeReference>(v.nodes[2]));
        assert!(is::<AstTypeReference>(v.nodes[3]));
        assert!(is::<AstTypeReference>(v.nodes[4]));
    });
}

#[test]
fn local_two_annotated_bindings_with_two_values() {
    with_block("local a: A, b: B<number> = 1, 2\n", |block| {
        let mut v = TrackingWiths::default();
        unsafe { (*block).visit(&mut v) };
        assert!(is::<AstStatBlock>(v.nodes[0]));
        assert!(is::<AstStatLocal>(v.nodes[1]));
        assert!(is::<AstTypeReference>(v.nodes[2]));
        assert!(is::<AstTypeReference>(v.nodes[3]));
        assert!(is::<AstTypeReference>(v.nodes[4]));
        assert!(is::<AstExprConstantNumber>(v.nodes[5]));
        assert!(is::<AstExprConstantNumber>(v.nodes[6]));
    });
}