OxideJS/crates/oxide_compiler/tests/compile_stmt_tests.rs

use oxide_compiler::compiler::Compiler;
use oxide_compiler::opcode::{self, OpCode};
use oxide_parser::Allocator;

fn compile_source(source: &str) -> oxide_compiler::module::CompiledModule {
    let allocator = Allocator::default();
    let program = oxide_parser::parse(&allocator, source).expect("parse failed");
    let compiler = Compiler::new();
    compiler.compile(&program).expect("compile failed")
}

#[test]
fn compile_var_declaration() {
    let module = compile_source("var x = 42;");
    assert!(!module.bytecode.is_empty());
    assert_eq!(
        module.constants[0],
        oxide_compiler::compiler::Constant::Int(42)
    );
}

#[test]
fn compile_return_nothing() {
    let module = compile_source("function f() { return; }");
    let last = opcode::opcode(*module.bytecode.last().unwrap());
    assert_eq!(last, OpCode::HALT);
}

#[test]
fn compile_return_value() {
    let module = compile_source("function f() { return 42; }");
    assert!(
        !module.bytecode.is_empty(),
        "function declaration should produce bytecode"
    );
}

#[test]
fn compile_if_else_emits_jmp_if_false() {
    let module = compile_source("if (true) { 1 } else { 2 }");
    assert!(
        module
            .bytecode
            .iter()
            .any(|&i| opcode::opcode(i) == OpCode::JMP_IF_FALSE),
        "if/else should contain JMP_IF_FALSE"
    );
    assert!(
        module
            .bytecode
            .iter()
            .any(|&i| opcode::opcode(i) == OpCode::JMP),
        "if/else should contain JMP"
    );
}

#[test]
fn compile_while_emits_jump_back() {
    let module = compile_source("while (true) { 1 }");
    let jmp_ops: Vec<_> = module
        .bytecode
        .iter()
        .filter(|&&i| opcode::opcode(i) == OpCode::JMP)
        .collect();
    assert!(!jmp_ops.is_empty(), "while should contain JMP (backward)");
    assert!(
        module
            .bytecode
            .iter()
            .any(|&i| opcode::opcode(i) == OpCode::JMP_IF_FALSE),
        "while should contain JMP_IF_FALSE"
    );
}

#[test]
fn compile_for_emits_jumps() {
    let module = compile_source("for (i=0; i<3; i=i+1) { 1 }");
    assert!(
        module
            .bytecode
            .iter()
            .any(|&i| opcode::opcode(i) == OpCode::JMP_IF_FALSE),
        "for should contain JMP_IF_FALSE"
    );
}

#[test]
fn compile_break_in_loop() {
    let module = compile_source("while (true) { break; }");
    assert!(
        !module.bytecode.is_empty(),
        "break should compile without error"
    );
}

#[test]
fn compile_continue_in_loop() {
    let module = compile_source("while (true) { continue; }");
    assert!(
        !module.bytecode.is_empty(),
        "continue should compile without error"
    );
}

#[test]
fn compile_break_outside_loop_errors() {
    let result = std::panic::catch_unwind(|| {
        compile_source("break;");
    });
    assert!(result.is_err(), "break outside loop should error");
}

#[test]
fn compile_continue_outside_loop_errors() {
    let result = std::panic::catch_unwind(|| {
        compile_source("continue;");
    });
    assert!(result.is_err(), "continue outside loop should error");
}

#[test]
fn compile_nested_if() {
    let module = compile_source("var a=1,b=0; if (a) { if (b) { 1 } else { 2 } }");
    let jmp_if_false_count = module
        .bytecode
        .iter()
        .filter(|&&i| opcode::opcode(i) == OpCode::JMP_IF_FALSE)
        .count();
    assert!(
        jmp_if_false_count >= 2,
        "nested if should have 2+ JMP_IF_FALSE"
    );
}

#[test]
fn compile_empty_while_body() {
    let module = compile_source("while (false) {}");
    assert!(!module.bytecode.is_empty(), "empty while should compile");
}

#[test]
fn regression_for_var_init() {
    let module = compile_source("for (var i = 0; i < 3; i = i + 1) {}");
    assert!(!module.bytecode.is_empty(), "for(var) init should compile");
    assert!(
        module
            .bytecode
            .iter()
            .any(|&i| opcode::opcode(i) == OpCode::JMP_IF_FALSE),
        "for(var) init should contain JMP_IF_FALSE"
    );
}

#[test]
fn regression_var_decl_counter_no_init() {
    let result = std::panic::catch_unwind(|| {
        compile_source("for (var i; i < 3; i = i + 1) {}");
    });
    assert!(
        result.is_err(),
        "for(var) without initializer should fail - accessing TDZ variable in test expression"
    );
}

#[test]
fn regression_redundant_jmp_if_without_else() {
    let module = compile_source("if (true) { 1 }");
    assert!(
        !module.bytecode.is_empty(),
        "if without else should compile"
    );
    let last = opcode::opcode(*module.bytecode.last().unwrap());
    assert_eq!(
        last,
        OpCode::HALT,
        "final opcode should be HALT, not dangling JMP"
    );
}