RustJava Agent Guidelines

Build/Test Commands

Build: cargo build (workspace), cargo build -p <crate> (single crate)
Test all: cargo test
Single test: cargo test <test_name> or cargo test -p <crate> <test_name>
Format: cargo fmt, Lint: cargo clippy

Edition: Rust 2024, #![no_std] for core crates (use alloc crate)
Line width: 150 chars (rustfmt.toml)
Indent: 4 spaces, LF line endings
Imports: Group alloc/core first, then external crates, then crate:: local imports
Naming: snake_case for functions/files, PascalCase for types/traits
Error handling: Use Result<T> (alias for result::Result<T, JavaError>), never panic in library code
Async: Use #[async_trait::async_trait] for async trait methods, #[tokio::test] for async tests

Keep rustjava-runtime/tests/classes limited to Java standard library class and API behavior.
Test JVM and interpreter semantics, including class initialization, bytecode execution, and monitor behavior, with compiled Java fixtures under test-data/src and expected output under test-data, executed by tests/test_class.rs.
Add or extend fixtures consumed by the existing test_class runner rather than adding Rust tests that directly invoke JVM APIs. For linkage errors that Java source cannot express directly, compile the caller against one class version and replace the target class in the fixture; keep the source variants and reproducible build instructions alongside it.
Do not place JVM core behavior tests in the rustjava-runtime standard library test tree.

Implement Java compatibility from public specifications, Javadocs, and observable behavior tests. Do not consult or reproduce OpenJDK or other Java runtime implementation source code; keep the implementation independent to avoid licensing and provenance concerns.