Test For

Find tests for: $ARGUMENTS

Steps:

1. Resolve the source file. If the argument is a file path, use it directly. If it's a class or symbol name, find its source file first.

2. Extract key symbols. Read the source file (header preferred) and identify the main exported symbols: class names, public method names, free function names, macros. These are what we'll search for in tests.

3. Find test targets. Look in the BUILD.bazel file in the same directory and in a tests/ subdirectory for wd_test() and kj_test() rules. For Rust files (.rs under src/rust/), also check for wd_rust_crate() rules which auto-generate <name>_test targets, and companion C++ test files (e.g., ffi-test.c++) that test the FFI bridge. Also check if the source file is a dependency of test targets:

   Copy

   bazel query 'rdeps(//src/..., <source_target>, 1)' --output label 2>/dev/null | grep -i test
   

4. Find test cases that reference the code. For each test file found, grep for the key symbols from step 2. Read the surrounding context to understand what each test case exercises. Tests for some C++ code may be in JavaScript test files if the C++ code is exposed to JS, so check those as well. For Rust code, also search .rs test files (including inline #[cfg(test)] modules and files under tests/ subdirectories) and the jsg-test harness tests.

5. Assess coverage. Compare the public API surface (from step 2) against what the tests exercise (from step 4). Identify:

   • Well-tested: symbols referenced in multiple test cases
   • Partially tested: symbols referenced but not thoroughly (e.g., only happy path)
   • Untested: public symbols with no test references

6. Output:

   • Source: file path and main symbols
   • Test targets: Bazel labels with just test commands
   • Test cases (grouped by test file):
     • file:line — description of what's tested (e.g., "tests TextEncoder with UTF-8 input")
   • Coverage assessment:
     • Well-tested: list of symbols
     • Gaps: list of public symbols with no apparent test coverage
   • Suggestions: specific test cases to add for untested code paths, if applicable