table of contents
- bookworm 0.66.0+ds1-1
- testing 1.82.0+dfsg1-2
- unstable 1.82.0+dfsg1-2
- experimental 1.83.0+dfsg1-1~exp1
CARGO-TEST(1) | General Commands Manual | CARGO-TEST(1) |
NAME¶
cargo-test — Execute unit and integration tests of a package
SYNOPSIS¶
cargo test [options] [testname] [-- test-options]
DESCRIPTION¶
Compile and execute unit, integration, and documentation tests.
The test filtering argument TESTNAME and all the arguments following the two dashes (--) are passed to the test binaries and thus to libtest (rustc’s built in unit-test and micro-benchmarking framework). If you’re passing arguments to both Cargo and the binary, the ones after -- go to the binary, the ones before go to Cargo. For details about libtest’s arguments see the output of cargo test -- --help and check out the rustc book’s chapter on how tests work at <https://doc.rust-lang.org/rustc/tests/index.html>.
As an example, this will filter for tests with foo in their name and run them on 3 threads in parallel:
cargo test foo -- --test-threads 3
Tests are built with the --test option to rustc which creates a special executable by linking your code with libtest. The executable automatically runs all functions annotated with the #[test] attribute in multiple threads. #[bench] annotated functions will also be run with one iteration to verify that they are functional.
If the package contains multiple test targets, each target compiles to a special executable as aforementioned, and then is run serially.
The libtest harness may be disabled by setting harness = false in the target manifest settings, in which case your code will need to provide its own main function to handle running tests.
Documentation tests¶
Documentation tests are also run by default, which is handled by rustdoc. It extracts code samples from documentation comments of the library target, and then executes them.
Different from normal test targets, each code block compiles to a doctest executable on the fly with rustc. These executables run in parallel in separate processes. The compilation of a code block is in fact a part of test function controlled by libtest, so some options such as --jobs might not take effect. Note that this execution model of doctests is not guaranteed and may change in the future; beware of depending on it.
See the rustdoc book <https://doc.rust-lang.org/rustdoc/> for more information on writing doc tests.
Working directory of tests¶
The working directory when running each unit and integration test is set to the root directory of the package the test belongs to. Setting the working directory of tests to the package’s root directory makes it possible for tests to reliably access the package’s files using relative paths, regardless from where cargo test was executed from.
For documentation tests, the working directory when invoking rustdoc is set to the workspace root directory, and is also the directory rustdoc uses as the compilation directory of each documentation test. The working directory when running each documentation test is set to the root directory of the package the test belongs to, and is controlled via rustdoc’s --test-run-directory option.
OPTIONS¶
Test Options¶
--no-run
--no-fail-fast
Package Selection¶
By default, when no package selection options are given, the packages selected depend on the selected manifest file (based on the current working directory if --manifest-path is not given). If the manifest is the root of a workspace then the workspaces default members are selected, otherwise only the package defined by the manifest will be selected.
The default members of a workspace can be set explicitly with the workspace.default-members key in the root manifest. If this is not set, a virtual workspace will include all workspace members (equivalent to passing --workspace), and a non-virtual workspace will include only the root crate itself.
-p spec…, --package spec…
--workspace
--all
--exclude SPEC…
Target Selection¶
When no target selection options are given, cargo test will build the following targets of the selected packages:
The default behavior can be changed by setting the test flag for the target in the manifest settings. Setting examples to test = true will build and run the example as a test, replacing the example’s main function with the libtest harness. If you don’t want the main function replaced, also include harness = false, in which case the example will be built and executed as-is.
Setting targets to test = false will stop them from being tested by default. Target selection options that take a target by name (such as --example foo) ignore the test flag and will always test the given target.
Doc tests for libraries may be disabled by setting doctest = false for the library in the manifest.
See Configuring a target <https://doc.rust-lang.org/cargo/reference/cargo-targets.html#configuring-a-target> for more information on per-target settings.
Binary targets are automatically built if there is an integration test or benchmark being selected to test. This allows an integration test to execute the binary to exercise and test its behavior. The CARGO_BIN_EXE_<name> environment variable <https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-crates> is set when the integration test is built so that it can use the env macro <https://doc.rust-lang.org/std/macro.env.html> to locate the executable.
Passing target selection flags will test only the specified targets.
Note that --bin, --example, --test and --bench flags also support common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each glob pattern.
--lib
--bin name…
--bins
--example name…
--examples
--test name…
--tests
--bench name…
--benches
--all-targets
--doc
Feature Selection¶
The feature flags allow you to control which features are enabled. When no feature options are given, the default feature is activated for every selected package.
See the features documentation <https://doc.rust-lang.org/cargo/reference/features.html#command-line-feature-options> for more details.
-F features, --features features
--all-features
--no-default-features
Compilation Options¶
--target triple
This may also be specified with the build.target config value <https://doc.rust-lang.org/cargo/reference/config.html>.
Note that specifying this flag makes Cargo run in a different mode where the target artifacts are placed in a separate directory. See the build cache <https://doc.rust-lang.org/cargo/guide/build-cache.html> documentation for more details.
-r, --release
--profile name
--timings=fmts
Output Options¶
--target-dir directory
Display Options¶
By default the Rust test harness hides output from test execution to keep results readable. Test output can be recovered (e.g., for debugging) by passing --nocapture to the test binaries:
cargo test -- --nocapture
-v, --verbose
-q, --quiet
--color when
May also be specified with the term.color config value <https://doc.rust-lang.org/cargo/reference/config.html>.
--message-format fmt
Manifest Options¶
--manifest-path path
--ignore-rust-version
--locked
It may be used in environments where deterministic builds are desired, such as in CI pipelines.
--offline
Beware that this may result in different dependency resolution than online mode. Cargo will restrict itself to crates that are downloaded locally, even if there might be a newer version as indicated in the local copy of the index. See the cargo-fetch(1) command to download dependencies before going offline.
May also be specified with the net.offline config value <https://doc.rust-lang.org/cargo/reference/config.html>.
--frozen
Common Options¶
+toolchain
--config KEY=VALUE or PATH
-C PATH
This option is only available on the nightly channel <https://doc.rust-lang.org/book/appendix-07-nightly-rust.html> and requires the -Z unstable-options flag to enable (see #10098 <https://github.com/rust-lang/cargo/issues/10098>).
-h, --help
-Z flag
Miscellaneous Options¶
The --jobs argument affects the building of the test executable but does not affect how many threads are used when running the tests. The Rust test harness includes an option to control the number of threads used:
cargo test -j 2 -- --test-threads=2
-j N, --jobs N
--future-incompat-report
See cargo-report(1)
While cargo test involves compilation, it does not provide a --keep-going flag. Use --no-fail-fast to run as many tests as possible without stopping at the first failure. To “compile” as many tests as possible, use --tests to build test binaries separately. For example:
cargo build --tests --keep-going cargo test --tests --no-fail-fast
ENVIRONMENT¶
See the reference <https://doc.rust-lang.org/cargo/reference/environment-variables.html> for details on environment variables that Cargo reads.
EXIT STATUS¶
EXAMPLES¶
cargo test
cargo test name_filter
cargo test --test int_test_name -- modname::test_name
SEE ALSO¶
cargo(1), cargo-bench(1), types of tests <https://doc.rust-lang.org/cargo/reference/cargo-targets.html#tests>, how to write tests <https://doc.rust-lang.org/rustc/tests/index.html>