[WIP] Add spl-token tests

[febo]

Problem

Currently the tests are limited to only test if instructions can execute.

Solution

Expand the tests by adding the same test suite as spl-token program.

[buffalojoec]

Before going too far with porting tests over from spl-token, might I suggest a simpler method.

We're already in the process of refactoring all of the spl-token tests with Mollusk.
solana-program/token#16

Once that's done, what we can do is the following:

1. Export all spl-token tests as fixtures.
2. Move that directory of fixture here in p-token.
3. Set up the Mollusk fixture entrypoint here in p-token (only a few lines of code).
4. Run all of the fixtures from spl-token against p-token.

Any unit test that invokes Mollusk's process_instruction or process_instruction_chain can generate a fixture.

cd spl-token
EJECT_FUZZ_FIXTURES=fixtures-dir cargo test-sbf

Then you can move those fixtures into the p-token repository here, and set up a simple Mollusk entrypoint to accept those fixtures.

for fix in fixtures_dir {
    let fixture = Fixture::load_from_blob_file(fix);
    Mollusk::process_and_validate_fixture(&fixture);
}

https://github.com/buffalojoec/mollusk/blob/c01523016195c315870bd9e4bfa3a64a6cffa659/harness/src/lib.rs#L356

And boom, that's it, you ran the whole spl-token suite against p-token.

[febo]

Before going too far with porting tests over from spl-token, might I suggest a simpler method.

We're already in the process of refactoring all of the spl-token tests with Mollusk. solana-program/token#16

Once that's done, what we can do is the following:

1. Export all spl-token tests as fixtures.
2. Move that directory of fixture here in p-token.
3. Set up the Mollusk fixture entrypoint here in p-token (only a few lines of code).
4. Run all of the fixtures from spl-token against p-token.

Any unit test that invokes Mollusk's process_instruction or process_instruction_chain can generate a fixture.

cd spl-token
EJECT_FUZZ_FIXTURES=fixtures-dir cargo test-sbf

Then you can move those fixtures into the p-token repository here, and set up a simple Mollusk entrypoint to accept those fixtures.

for fix in fixtures_dir {
    let fixture = Fixture::load_from_blob_file(fix);
    Mollusk::process_and_validate_fixture(&fixture);
}

https://github.com/buffalojoec/mollusk/blob/c01523016195c315870bd9e4bfa3a64a6cffa659/harness/src/lib.rs#L356

And boom, that's it, you ran the whole spl-token suite against p-token.

Amazing!

The tests here are literally a copy-paste from spl-token and just needed to change the program id constant. At the moment it is more just a quick way to check that they work. ☺️

I will definitely follow your suggestion when adding the final tests.

[febo]

@buffalojoec Given the way that we ended up doing the spl-token tests, I think we can't use the fixtures – if I understood how mollusk fixtures work. We don't pass the checks to mollusk since we rely on "external" assert!s so we don't have that information on the fixtures.