luau_analyzer_sys/

lib.rs

use std::collections::HashMap;
use std::ffi::{CStr, CString};
use std::os::raw::{c_char, c_int, c_uint, c_void};

#[derive(Debug, Clone)]
pub struct Diagnostic {
    pub severity: u8, // 0 for error, 1 for warning
    pub line: u32,
    pub col: u32,
    pub end_line: u32,
    pub end_col: u32,
    pub message: String,
}

#[repr(C)]
pub struct LuauAnalyzerOpaque {
    _private: [u8; 0],
}

type DiagnosticCallback = unsafe extern "C" fn(
    context: *mut c_void,
    severity: c_int,
    line: c_uint,
    col: c_uint,
    end_line: c_uint,
    end_col: c_uint,
    message: *const c_char,
);

type ReadSourceCallback =
    unsafe extern "C" fn(context: *mut c_void, module_name: *const c_char) -> *const c_char;

type ResolveModuleCallback = unsafe extern "C" fn(
    context: *mut c_void,
    current_module: *const c_char,
    required_name: *const c_char,
) -> *const c_char;

unsafe extern "C" {
    fn luau_analyzer_create() -> *mut LuauAnalyzerOpaque;
    fn luau_analyzer_destroy(analyzer: *mut LuauAnalyzerOpaque);
    fn luau_analyzer_add_definitions(analyzer: *mut LuauAnalyzerOpaque, source: *const c_char);
    fn luau_analyzer_check(
        analyzer: *mut LuauAnalyzerOpaque,
        module_name: *const c_char,
        read_callback: Option<ReadSourceCallback>,
        resolve_callback: Option<ResolveModuleCallback>,
        diag_callback: Option<DiagnosticCallback>,
        context: *mut c_void,
    );
}

struct CheckContext<'a> {
    diagnostics: Vec<Diagnostic>,
    cached_strings: HashMap<String, CString>,
    resolver: &'a dyn Fn(&str) -> Option<String>,
    path_resolver: &'a dyn Fn(&str, &str) -> Option<String>,
}

pub struct NativeAnalyzer {
    ptr: *mut LuauAnalyzerOpaque,
}

impl NativeAnalyzer {
    pub fn new() -> Self {
        unsafe {
            Self {
                ptr: luau_analyzer_create(),
            }
        }
    }

    pub fn add_definitions(&mut self, source: &str) {
        if let Ok(c_str) = CString::new(source) {
            unsafe {
                luau_analyzer_add_definitions(self.ptr, c_str.as_ptr());
            }
        }
    }

    pub fn check<F, P>(
        &mut self,
        module_name: &str,
        resolver: F,
        path_resolver: P,
    ) -> Vec<Diagnostic>
    where
        F: Fn(&str) -> Option<String>,
        P: Fn(&str, &str) -> Option<String>,
    {
        let mut context = CheckContext {
            diagnostics: Vec::new(),
            cached_strings: HashMap::new(),
            resolver: &resolver,
            path_resolver: &path_resolver,
        };

        if let Ok(mod_cstr) = CString::new(module_name) {
            unsafe extern "C" fn read_callback(
                ctx_ptr: *mut c_void,
                mod_name: *const c_char,
            ) -> *const c_char {
                let ctx = unsafe { &mut *(ctx_ptr as *mut CheckContext) };
                if mod_name.is_null() {
                    return std::ptr::null();
                }
                let name_str = unsafe { CStr::from_ptr(mod_name) }.to_string_lossy();
                if let Some(c_str) = ctx.cached_strings.get(name_str.as_ref()) {
                    return c_str.as_ptr();
                }
                if let Some(src) = (ctx.resolver)(name_str.as_ref())
                    && let Ok(c_str) = CString::new(src)
                {
                    let ptr = c_str.as_ptr();
                    ctx.cached_strings.insert(name_str.into_owned(), c_str);
                    return ptr;
                }
                std::ptr::null()
            }

            unsafe extern "C" fn resolve_callback(
                ctx_ptr: *mut c_void,
                curr_mod: *const c_char,
                req_name: *const c_char,
            ) -> *const c_char {
                let ctx = unsafe { &mut *(ctx_ptr as *mut CheckContext) };
                if curr_mod.is_null() || req_name.is_null() {
                    return std::ptr::null();
                }
                let curr_mod_str = unsafe { CStr::from_ptr(curr_mod) }.to_string_lossy();
                let req_name_str = unsafe { CStr::from_ptr(req_name) }.to_string_lossy();

                let cache_key = format!("RESOLVED:{}:{}", curr_mod_str, req_name_str);
                if let Some(c_str) = ctx.cached_strings.get(&cache_key) {
                    return c_str.as_ptr();
                }

                if let Some(resolved) =
                    (ctx.path_resolver)(curr_mod_str.as_ref(), req_name_str.as_ref())
                    && let Ok(c_str) = CString::new(resolved)
                {
                    let ptr = c_str.as_ptr();
                    ctx.cached_strings.insert(cache_key, c_str);
                    return ptr;
                }
                std::ptr::null()
            }

            unsafe extern "C" fn diag_callback(
                ctx_ptr: *mut c_void,
                severity: c_int,
                line: c_uint,
                col: c_uint,
                end_line: c_uint,
                end_col: c_uint,
                message: *const c_char,
            ) {
                let ctx = unsafe { &mut *(ctx_ptr as *mut CheckContext) };
                let msg_str = if message.is_null() {
                    String::new()
                } else {
                    unsafe { CStr::from_ptr(message) }
                        .to_string_lossy()
                        .into_owned()
                };
                ctx.diagnostics.push(Diagnostic {
                    severity: severity as u8,
                    line,
                    col,
                    end_line,
                    end_col,
                    message: msg_str,
                });
            }

            unsafe {
                let ctx_void = &mut context as *mut CheckContext as *mut c_void;
                luau_analyzer_check(
                    self.ptr,
                    mod_cstr.as_ptr(),
                    Some(read_callback),
                    Some(resolve_callback),
                    Some(diag_callback),
                    ctx_void,
                );
            }
        }

        context.diagnostics
    }
}

impl Default for NativeAnalyzer {
    fn default() -> Self {
        Self::new()
    }
}

impl Drop for NativeAnalyzer {
    fn drop(&mut self) {
        unsafe {
            if !self.ptr.is_null() {
                luau_analyzer_destroy(self.ptr);
                self.ptr = std::ptr::null_mut();
            }
        }
    }
}

unsafe impl Send for NativeAnalyzer {}

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

    #[test]
    fn test_create_analyzer() {
        let analyzer = NativeAnalyzer::new();
        assert!(!analyzer.ptr.is_null());
    }

    #[test]
    fn test_check_simple_no_errors() {
        let mut analyzer = NativeAnalyzer::new();
        let source = "local _x: number = 10\nlocal _y: number = _x + 5\n";

        let diagnostics = analyzer.check(
            "main",
            |name| {
                if name == "main" {
                    Some(source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );

        assert!(
            diagnostics.is_empty(),
            "Expected no diagnostics, got: {:?}",
            diagnostics
        );
    }

    #[test]
    fn test_check_type_error() {
        let mut analyzer = NativeAnalyzer::new();
        // Intentional type error: assigning string to a number variable
        let source = "local _x: number = 'hello'\n";

        let diagnostics = analyzer.check(
            "main",
            |name| {
                if name == "main" {
                    Some(source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );

        assert!(
            !diagnostics.is_empty(),
            "Expected at least one type error diagnostic"
        );
        let diag = &diagnostics[0];
        assert!(
            diag.severity == 0 || diag.severity == 1,
            "Expected error or warning severity, got: {}",
            diag.severity
        );
        assert!(
            diag.message.contains("string"),
            "Expected message to mention 'string', got: {}",
            diag.message
        );
        assert!(
            diag.message.contains("number"),
            "Expected message to mention 'number', got: {}",
            diag.message
        );
    }

    #[test]
    fn test_check_syntax_error() {
        let mut analyzer = NativeAnalyzer::new();
        // Syntax error: missing end of statement/operator
        let source = "local x = \n";

        let diagnostics = analyzer.check(
            "main",
            |name| {
                if name == "main" {
                    Some(source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );

        assert!(!diagnostics.is_empty(), "Expected syntax error diagnostic");
        // Syntax error is usually severity 0 (error)
        assert_eq!(diagnostics[0].severity, 0);
    }

    #[test]
    fn test_check_with_submodule() {
        let mut analyzer = NativeAnalyzer::new();
        let main_source = "local dep = require('dependency')\nlocal _x: number = dep.value\n";
        let dep_source = "local M = {}\nM.value = 42\nreturn M\n";

        let diagnostics = analyzer.check(
            "main",
            |name| match name {
                "main" => Some(main_source.to_string()),
                "dependency" => Some(dep_source.to_string()),
                _ => None,
            },
            |current, required| {
                if current == "main" && required == "dependency" {
                    Some("dependency".to_string())
                } else {
                    None
                }
            },
        );

        assert!(
            diagnostics.is_empty(),
            "Expected no diagnostics, got: {:?}",
            diagnostics
        );
    }

    #[test]
    fn test_multiple_checks_same_analyzer() {
        let mut analyzer = NativeAnalyzer::new();

        let src1 = "local _x: number = 10\n";
        let diagnostics1 = analyzer.check(
            "mod1",
            |name| {
                if name == "mod1" {
                    Some(src1.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );
        assert!(diagnostics1.is_empty());

        let src2 = "local _y: string = 'hello'\n";
        let diagnostics2 = analyzer.check(
            "mod2",
            |name| {
                if name == "mod2" {
                    Some(src2.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );
        assert!(diagnostics2.is_empty());
    }

    #[test]
    fn test_custom_definitions() {
        let mut analyzer = NativeAnalyzer::new();
        // Register a custom global function `my_global_helper`
        analyzer.add_definitions("declare function my_global_helper(val: string): number\n");

        // Code that uses the custom global function correctly
        let correct_source = "--!strict\nlocal _x: number = my_global_helper('test')\n";
        let diagnostics = analyzer.check(
            "main_correct",
            |name| {
                if name == "main_correct" {
                    Some(correct_source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );
        assert!(
            diagnostics.is_empty(),
            "Expected no diagnostics, got: {:?}",
            diagnostics
        );

        // Code that uses it incorrectly (type mismatch: passing number instead of string)
        let incorrect_source = "--!strict\nlocal _x: number = my_global_helper(123)\n";
        let diagnostics2 = analyzer.check(
            "main_incorrect",
            |name| {
                if name == "main_incorrect" {
                    Some(incorrect_source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );
        println!("test_custom_definitions diagnostics: {:?}", diagnostics2);
        assert!(
            !diagnostics2.is_empty(),
            "Expected a type error due to parameter type mismatch"
        );
        let msg = &diagnostics2[0].message;
        assert!(
            msg.contains("number") || msg.contains("string"),
            "Got message: {}",
            msg
        );
    }

    #[test]
    fn test_precise_error_coordinates() {
        let mut analyzer = NativeAnalyzer::new();
        // Error on line 3 (0-indexed line 2), column 19:
        // Line 1: --!strict
        // Line 2: local _x: number = 10
        // Line 3: local _y: string = 20
        let source = "--!strict\nlocal _x: number = 10\nlocal _y: string = 20\n";

        let diagnostics = analyzer.check(
            "main_precise",
            |name| {
                if name == "main_precise" {
                    Some(source.to_string())
                } else {
                    None
                }
            },
            |_, _| None,
        );

        assert!(!diagnostics.is_empty());
        let diag = &diagnostics[0];
        // In Luau, line numbers in error locations are 0-based.
        // Line 3 is index 2.
        assert_eq!(diag.line, 2);
        assert!(diag.col < 100);
    }

    #[test]
    fn test_resolver_returns_none() {
        use std::cell::RefCell;
        use std::rc::Rc;

        let mut analyzer = NativeAnalyzer::new();
        let source = "--!strict\nlocal _dep = require('missing_module')\n";

        let resolver_called = Rc::new(RefCell::new(false));
        let resolver_called_clone = resolver_called.clone();

        let diagnostics = analyzer.check(
            "main_resolver",
            |name| {
                if name == "main_resolver" {
                    Some(source.to_string())
                } else {
                    if name == "missing_module" {
                        *resolver_called_clone.borrow_mut() = true;
                    }
                    None // fails to load
                }
            },
            |current, required| {
                if current == "main_resolver" && required == "missing_module" {
                    Some("missing_module".to_string())
                } else {
                    None
                }
            },
        );

        println!("test_resolver_returns_none diagnostics: {:?}", diagnostics);
        // Verify that the resolver was indeed called with the missing module name
        assert!(*resolver_called.borrow());
        // And diagnostics for the entry file is empty because errors on the required module are filtered out
        assert!(diagnostics.is_empty());
    }

    #[test]
    fn test_multithreaded_analyzer() {
        use std::thread;

        let mut analyzer = NativeAnalyzer::new();
        analyzer.add_definitions("declare function thread_safe_helper(): ()\n");

        // NativeAnalyzer is Send, so we can move it to another thread
        let handle = thread::spawn(move || {
            let source = "thread_safe_helper()\n";
            let diagnostics = analyzer.check(
                "main",
                |name| {
                    if name == "main" {
                        Some(source.to_string())
                    } else {
                        None
                    }
                },
                |_, _| None,
            );
            assert!(diagnostics.is_empty());
            analyzer // Return it back
        });

        let _analyzer = handle.join().unwrap();
    }

    #[test]
    fn test_default_analyzer() {
        // Test Default trait implementation
        let analyzer = NativeAnalyzer::default();
        assert!(!analyzer.ptr.is_null());
    }

    #[test]
    fn test_diagnostics_clone_and_debug() {
        let diag = Diagnostic {
            severity: 0,
            line: 1,
            col: 2,
            end_line: 3,
            end_col: 4,
            message: "Test message".to_string(),
        };

        let cloned = diag.clone();
        assert_eq!(cloned.severity, diag.severity);
        assert_eq!(cloned.line, diag.line);
        assert_eq!(cloned.col, diag.col);
        assert_eq!(cloned.end_line, diag.end_line);
        assert_eq!(cloned.end_col, diag.end_col);
        assert_eq!(cloned.message, diag.message);

        let debug_str = format!("{:?}", diag);
        assert!(debug_str.contains("Test message"));
    }

    #[test]
    fn test_check_with_nested_relative_modules() {
        let mut analyzer = NativeAnalyzer::new();

        // main requires foo/bar, which in turn requires ../baz
        let main_src = "local _bar = require('foo/bar')\n";
        let bar_src = "local _baz = require('../baz')\nlocal M = {}\nreturn M\n";
        let baz_src = "local M = {}\nM.value = 100\nreturn M\n";

        let diagnostics = analyzer.check(
            "main",
            |name| match name {
                "main" => Some(main_src.to_string()),
                "foo/bar" => Some(bar_src.to_string()),
                "baz" => Some(baz_src.to_string()),
                _ => None,
            },
            |current, required| {
                if current == "main" && required == "foo/bar" {
                    Some("foo/bar".to_string())
                } else if current == "foo/bar" && required == "../baz" {
                    // Resolve relative path "../baz" from "foo/bar" to "baz"
                    Some("baz".to_string())
                } else {
                    None
                }
            },
        );

        assert!(
            diagnostics.is_empty(),
            "Expected no diagnostics, got: {:?}",
            diagnostics
        );
    }
}