JUnit test example for wasm

[treblereel]

JUnit test example for wasm

[gkdn]

It works the same way as JavaScript however we cannot add it to CI since it doesn't have binaryen integration (currently assumes binaryen is in the path).

@mollyibot Could you manually test this to check if we are missing anything?

[mollyibot]

I first changed j2wasm_generate_jsunit_suite to take Label("//build_defs/internal_do_not_use:internal_junit_runtime-j2wasm") instead of "//build_defs/internal_do_not_use:internal_junit_runtime-j2wasm", then bazel build //src/test/java/com/google/j2cl/samples/helloworldlib:HelloWorldTest_generated_suite_j2wasm_application but it gives me an error Binaryen (wasm-opt) is not available. Aborting., Any thoughts?

[gkdn]

We expect binaryen to be available on the path. See here:
https://github.com/google/j2cl/blob/dcf29c75c6e79713987e620eb220cf540e8eb708/third_party/binaryen.sh

[treblereel]

@gkdn cool, thanks a million!