Testing

fd has two complementary layers of tests:

1. Unit tests in #[cfg(test)] mod tests blocks inside production modules. These cover pure logic (size parsing, time parsing, owner parsing, format-template parsing, exit-code merging, regex helpers, hyperlink encoding, walk::search_str_for_entry, …).
2. Integration tests in tests/tests.rs (~2,800 lines) that spawn the real binary, run it against a synthetic temporary directory tree, and assert on its stdout.

Unit tests

Located inline. Examples:

Module	What it tests
src/regex_helper.rs	pattern_has_uppercase_char, pattern_matches_strings_with_leading_dot.
src/filter/size.rs	Parsing every supported size suffix (b, k/kb/ki/kib, …, t/tb/ti/tib) and the is_within predicate.
src/filter/time.rs	TimeFilter::before/after over Span, Timestamp, DateTime, and @<unix-seconds> formats with a thread-local TESTTIME override.
src/filter/owner.rs	OwnerFilter::from_string for every documented input.
src/exit_codes.rs	merge_exitcodes truth table.
src/exec/mod.rs	CommandSet/CommandTemplate parsing and placeholder expansion.
src/fmt/mod.rs and src/fmt/input.rs	FormatTemplate::parse/generate and the basename/dirname/remove_extension helpers.
src/walk.rs	search_str_for_entry for relative, absolute, and dot-prefixed paths.
src/filesystem.rs	strip_current_dir.
src/hyperlink.rs	Percent-encoding of non-ASCII path bytes.

Run only unit tests:

cargo test --lib

Integration tests and TestEnv

Integration tests live in tests/tests.rs and use the harness in tests/testenv/mod.rs. The harness:

• Locates the just-built binary via the CARGO_BIN_EXE_fd env var that Cargo provides to integration tests (tests/testenv/mod.rs).
• Creates a temporary directory under a fd-tests prefix (tempfile::Builder).
• Pre-populates a fixed tree of directories, files, and one symlink (symlink → one/two). On Windows, the symlink only works if the test process has SeCreateSymbolicLinkPrivilege.
• Drops a .fdignore containing fdignored.foo and a .gitignore containing gitignored.foo.
• Pretends to be a git repository by mkdir-ing a .git/ directory at the temp root, so VCS-ignore handling kicks in.
• Optionally creates a separate "config" temp dir holding fd/ignore for the global ignore file (create_config_directory_with_global_ignore).

The TestEnv::assert_output API runs the binary with given args and asserts on a normalised stdout string (the harness replaces \0 with NULL\n, optionally sorts whitespace-separated tokens per line, and produces a unified diff on failure via the diff crate).

Typical usage in tests/tests.rs:

let te = TestEnv::new();
te.assert_output(
    &["a.foo"],
    "a.foo\n\
     one/a.foo\n\
     one/two/a.foo\n\
     one/two/three/a.foo\n",
);

How to add a test

1. Pick the right layer. Pure logic (parsers, predicates) belongs in a unit-test module next to the code. Anything that depends on the actual binary, the filesystem walker, or the global ignore file belongs in tests/tests.rs.
2. For integration tests, copy an existing #[test] fn … and tailor the args. If you need a new file or directory in the fixture, add it to the lists at the top of create_working_directory in tests/testenv/mod.rs. Be aware that this affects every test — they all share the same tree shape.
3. For platform-specific tests, use the standard #[cfg(unix)] / #[cfg(windows)] attributes. Several existing tests do this, especially around symlinks, owners, and path separators.

Running tests

# Everything
cargo test --all-features

# A single test
cargo test test_simple_search

# Integration tests only (the file in tests/)
cargo test --test tests

Test data outside the harness

A handful of tests rely on additional crates:

• test-case for parameterised tests.
• tempfile for ad-hoc temp directories beyond the harness.
• filetime for setting precise mtimes when testing --changed-within / --changed-before.
• diff for the unified-diff output on failure.

These are listed under [dev-dependencies] in Cargo.toml.

CI matrix

.github/workflows/CICD.yml runs cargo test across multiple targets (Linux, macOS, Windows, plus several musl and ARM variants) and additionally runs an MSRV job pinned to the version declared in Cargo.toml.