Rust 测试的 GN 规则

The simplest way to build Rust gtest tests is to add them to an existing test binary that already contains tests authored in C++. For example:

1. test("ui_base_unittests") {
2. ...
3. sources += [ "my_rust_lib_unittest.rs" ]
4. deps += [ ":my_rust_lib" ]
5. }

Authoring Rust tests in a separate static_library also works, but requires manually declaring the dependency on the support libraries:

1. rust_static_library("my_rust_lib_unittests") {
2. testonly = true
3. is_gtest_unittests = true
4. crate_root = "my_rust_lib_unittest.rs"
5. sources = [ "my_rust_lib_unittest.rs" ]
6. deps = [
7. ":my_rust_lib",
8. "//testing/rust_gtest_interop",
9. ]
10. }

12. test("ui_base_unittests") {
13. ...
14. deps += [ ":my_rust_lib_unittests" ]
15. }