test(forge): solar test runner

[0xrusowsky]

this is what i'm trying to implement: foundry-rs#10405 (comment)

these are ok for now but I would like to import the test runner and logic from solar, which, like rustc, uses a directory walk and runs each file individually with custom annotations for config and expected errors; see https://docs.rs/ui_test/latest/ui_test/ and https://github.com/paradigmxyz/solar/blob/main/CONTRIBUTING.md#tests

I think we can just import and set up ui_test directly, and make it run forge lint on the file

---

• added a new test util runner.rs, so that any crate can run "ui tests"
• added a new flag with_json_emitter to SolidityLinter for testing purposes:

  impl Linter for SolidityLinter {
     type Language = SolcLanguage;
     type Lint = SolLint;
  
     fn lint(&self, input: &[PathBuf]) {
         let mut builder = Session::builder();
         let map = Arc::<SourceMap>::default();
  
         // Build session based on the linter config
         if self.with_json_emitter {
             let json_emitter = JsonEmitter::new(Box::new(std::io::stderr()), map.clone())
                 .rustc_like(true)
                 .ui_testing(false);
             let dcx = DiagCtxt::new(Box::new(json_emitter));
  
             builder = builder.dcx(dcx);
         } else {
             builder = builder.with_stderr_emitter();
         };
  
         // Create a single session for all files
         let mut sess = builder.source_map(map.clone()).build();
         sess.dcx = sess.dcx.set_flags(|flags| flags.track_diagnostics = false);
  
         // Process the files in parallel
         sess.enter_parallel(|| {
             input.into_par_iter().for_each(|file| {
                 self.process_file(&sess, file);
             });
         });
     }
  }

• added the annotations to the solidity files to highlight the warnings/notes that the linter should emit

outputs

• when i run the integration tests for the CLI cmds, i do see that the json emitter works properly:

{"$message_type":"diag","message":"","code":{"code":"divide-before-multiply","explanation":null},"level":"warning","spans":[{"file_name":"/private/var/folders/vq/wp74kqr523x_tp8sd4qgs35w0000gn/T/can_use_config-05tblQV/src/ContractWithLints.sol","byte_start":388,"byte_end":399,"line_start":16,"line_end":16,"column_start":9,"column_end":20,"is_primary":true,"text":[{"text":"        (1 / 2) * 3;","highlight_start":9,"highlight_end":20}],"label":null}],"children":[{"message":"multiplication should occur before division to avoid loss of precision","code":null,"level":"help","spans":[],"children":[],"rendered":null}],"rendered":"warning[divide-before-multiply]/n  [FILE]:16:9/n   |/n16 |         (1 / 2) * 3;/n   |         -----------/n   |/n   = help: multiplication should occur before division to avoid loss of precision/n/n"}

• i can see that after running the ui tests setting args.bless = true, the .stderr files are generated (included in the PR) --> makes me think that the setup can't be too far from being correct.

however, when running cargo test -p forge --test ui none of the tests pass:

✗  cargo test -p forge --test ui                                                                                                                                                                                                                              [ 06:40:54 PM ]
   Compiling forge v1.1.0 (/Users/rusowsky/dev/ithaca/foundry/crates/forge)
    Finished `test` profile [unoptimized + debuginfo] target(s) in 5.26s
     Running tests/ui/main.rs (target/debug/deps/ui-d11fb785c0016a76)

running 1 test
███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████ 6/6test lint::forge_lint_ui_tests ... FAILED

failures:

---- lint::forge_lint_ui_tests stdout ----
Attempting to use forge executable at: /Users/rusowsky/dev/ithaca/foundry/target/debug/forge
Forge executable exists.
Forge --version stdout: forge Version: 1.1.0-dev
Commit SHA: 945ec589d0410617f564a5bfebc897610d3f1689
Build Timestamp: 2025-05-07T16:40:26.762823000Z (1746636026)
Build Profile: debug

Forge --version stderr:
Forge --version status: exit status: 0
ui_test root_dir: /Users/rusowsky/dev/ithaca/foundry/crates/lint/testdata
ui_test out_dir: /Users/rusowsky/dev/ithaca/foundry/crates/lint/target/ui
ui_test program path: /Users/rusowsky/dev/ithaca/foundry/target/debug/forge
ui_test program args: ["lint"]


FAILED TEST: /Users/rusowsky/dev/ithaca/foundry/crates/lint/testdata/Keccak256.sol
command: "/Users/rusowsky/dev/ithaca/foundry/target/debug/forge" "lint" "/Users/rusowsky/dev/ithaca/foundry/crates/lint/testdata/Keccak256.sol"

error: `asm-keccak256` not found in diagnostics on line 3
 --> /Users/rusowsky/dev/ithaca/foundry/crates/lint/testdata/Keccak256.sol:3:53
  |
3 |         keccak256(abi.encodePacked(a, b)); //~NOTE: asm-keccak256
  |                                                     ^^^^^^^^^^^^^ expected because of this pattern
  |

error: `asm-keccak256` not found in diagnostics on line 7
 --> /Users/rusowsky/dev/ithaca/foundry/crates/lint/testdata/Keccak256.sol:7:53
  |
7 |         keccak256(abi.encodePacked(a, b)); //~NOTE: asm-keccak256
  |                                                     ^^^^^^^^^^^^^ expected because of this pattern
  |