fix(test-cli-fill): Use default evm-dump-dir for traces; gitignore it

Author: fselmo

.gitignore

@@ -76,6 +76,9 @@ tests/t8n_testdata
 
 fixtures/
 
+# Trace output (generated by --traces flag)
+traces/
+
 logs/
 *.log
 

docs/filling_tests/debugging_t8n_tools.md

@@ -8,7 +8,8 @@ There are two flags that can help debugging `t8n` tools or the execution-spec-te
 
 ## EVM Dump Directory
 
-The `--evm-dump-dir` flag tells the framework to write the inputs and outputs of every call made to the `t8n` command to the specified output directory. The aim is to help debugging or simply understand how a test is interacting with the EVM. Debug output is only generated when this flag is explicitly specified.
+The `--evm-dump-dir` flag tells the framework to write the inputs and outputs of every call made to the `t8n` command to the specified output directory. The aim is to help debugging or simply understand how a test is interacting with the EVM.
+When `--traces` is specified without an explicit `--evm-dump-dir`, a default directory of `traces/` is used.
 
 Each test case receives its own sub-directory under the `--evm-dump-dir` that contains these files which can be easily accessed from the HTML test report generated by `fill` (located by default in the root of the `--output` directory).
 

packages/testing/src/execution_testing/cli/pytest_commands/plugins/filler/filler.py

@@ -723,6 +723,13 @@ def pytest_configure(config: pytest.Config) -> None:
         or config.getoption("optimize_gas", False)
     )
 
+    # set default for --evm-dump-dir
+    if (
+        config.collect_traces  # type: ignore[attr-defined]
+        and config.getoption("base_dump_dir")
+    ) is None:
+        config.option.base_dump_dir = "traces"
+
     # Instantiate the transition tool here to check that the binary path/trace
     # option is valid. This ensures we only raise an error once, if
     # appropriate, instead of for every test.