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 and integration 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.
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 an
executable with a main function that 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.
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 are also run by default, which is handled by
rustdoc. It extracts code samples from documentation comments and
executes them. See the rustdoc book <https://doc.rust-lang.org/rustdoc/>
for more information on writing doc tests.
OPTIONS
Test Options
--no-run
Compile, but don't run tests.
--no-fail-fast
Run all tests regardless of failure. Without this flag, Cargo will
exit after the first executable fails. The Rust test harness will
run all tests within the executable to completion, this flag only
applies to the executable as a whole.
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...
Test only the specified packages. See cargo-pkgid(1) for the SPEC
format. This flag may be specified multiple times.
--workspace
Test all members in the workspace.
--all
Deprecated alias for --workspace.
--exclude SPEC...
Exclude the specified packages. Must be used in conjunction with the
--workspace flag. This flag may be specified multiple times.
Target Selection
When no target selection options are given, cargo test will build the
following targets of the selected packages:
o lib — used to link with binaries, examples, integration tests, and
doc tests
o bins (only if integration tests are built and required features are
available)
o examples — to ensure they compile
o lib as a unit test
o bins as unit tests
o integration tests
o doc tests for the lib target
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. Setting targets to test = false
will stop them from being tested by default. Target selection options
that take a target by name 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.
Binary targets are automatically built if there is an integration test
or benchmark. 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.
--lib
Test the package's library.
--bin name...
Test the specified binary. This flag may be specified multiple
times.
--bins
Test all binary targets.
--example name...
Test the specified example. This flag may be specified multiple
times.
--examples
Test all example targets.
--test name...
Test the specified integration test. This flag may be specified
multiple times.
--tests
Test all targets in test mode that have the test = true manifest
flag set. By default this includes the library and binaries built as
unittests, and integration tests. Be aware that this will also build
any required dependencies, so the lib target may be built twice
(once as a unittest, and once as a dependency for binaries,
integration tests, etc.). Targets may be enabled or disabled by
setting the test flag in the manifest settings for the target.
--bench name...
Test the specified benchmark. This flag may be specified multiple
times.
--benches
Test all targets in benchmark mode that have the bench = true
manifest flag set. By default this includes the library and binaries
built as benchmarks, and bench targets. Be aware that this will also
build any required dependencies, so the lib target may be built
twice (once as a benchmark, and once as a dependency for binaries,
benchmarks, etc.). Targets may be enabled or disabled by setting the
bench flag in the manifest settings for the target.
--all-targets
Test all targets. This is equivalent to specifying --lib --bins
--tests --benches --examples.
--doc
Test only the library's documentation. This cannot be mixed with
other target options.
Feature Selection
The feature flags allow you to control the enabled features for the
"current" package. The "current" package is the package in the current
directory, or the one specified in --manifest-path. If running in the
root of a virtual workspace, then the default features are selected for
all workspace members, or all features if --all-features is specified.
When no feature options are given, the default feature is activated for
every selected package.
--features features
Space or comma separated list of features to activate. These
features only apply to the current directory's package. Features of
direct dependencies may be enabled with <dep-name>/<feature-name>
syntax. This flag may be specified multiple times, which enables all
specified features.
--all-features
Activate all available features of all selected packages.
--no-default-features
Do not activate the default feature of the current directory's
package.
Compilation Options
--target triple
Test for the given architecture. The default is the host
architecture. The general format of the triple is
<arch><sub>-<vendor>-<sys>-<abi>. Run rustc --print target-list for
a list of supported targets.
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.
--release
Test optimized artifacts with the release profile. See the PROFILES
section for details on how this affects profile selection.
Output Options
--target-dir directory
Directory for all generated artifacts and intermediate files. May
also be specified with the CARGO_TARGET_DIR environment variable, or
the build.target-dir config value
<https://doc.rust-lang.org/cargo/reference/config.html>. Defaults to
target in the root of the workspace.
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
Use verbose output. May be specified twice for "very verbose" output
which includes extra output such as dependency warnings and build
script output. May also be specified with the term.verbose config
value <https://doc.rust-lang.org/cargo/reference/config.html>.
-q, --quiet
No output printed to stdout.
--color when
Control when colored output is used. Valid values:
o auto (default): Automatically detect if color support is
available on the terminal.
o always: Always display colors.
o never: Never display colors.
May also be specified with the term.color config value
<https://doc.rust-lang.org/cargo/reference/config.html>.
--message-format fmt
The output format for diagnostic messages. Can be specified multiple
times and consists of comma-separated values. Valid values:
o human (default): Display in a human-readable text format.
o short: Emit shorter, human-readable text messages.
o json: Emit JSON messages to stdout. See the reference
<https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages>
for more details.
o json-diagnostic-short: Ensure the rendered field of JSON messages
contains the "short" rendering from rustc.
o json-diagnostic-rendered-ansi: Ensure the rendered field of JSON
messages contains embedded ANSI color codes for respecting
rustc's default color scheme.
o json-render-diagnostics: Instruct Cargo to not include rustc
diagnostics in in JSON messages printed, but instead Cargo itself
should render the JSON diagnostics coming from rustc. Cargo's own
JSON diagnostics and others coming from rustc are still emitted.
Manifest Options
--manifest-path path
Path to the Cargo.toml file. By default, Cargo searches for the
Cargo.toml file in the current directory or any parent directory.
--frozen, --locked
Either of these flags requires that the Cargo.lock file is
up-to-date. If the lock file is missing, or it needs to be updated,
Cargo will exit with an error. The --frozen flag also prevents Cargo
from attempting to access the network to determine if it is
out-of-date.
These may be used in environments where you want to assert that the
Cargo.lock file is up-to-date (such as a CI build) or want to avoid
network access.
--offline
Prevents Cargo from accessing the network for any reason. Without
this flag, Cargo will stop with an error if it needs to access the
network and the network is not available. With this flag, Cargo will
attempt to proceed without the network if possible.
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>.
Common Options
+toolchain
If Cargo has been installed with rustup, and the first argument to
cargo begins with +, it will be interpreted as a rustup toolchain
name (such as +stable or +nightly). See the rustup documentation
<https://rust-lang.github.io/rustup/overrides.html> for more
information about how toolchain overrides work.
-h, --help
Prints help information.
-Z flag
Unstable (nightly-only) flags to Cargo. Run cargo -Z help for
details.
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
Number of parallel jobs to run. May also be specified with the
build.jobs config value
<https://doc.rust-lang.org/cargo/reference/config.html>. Defaults to
the number of CPUs.
PROFILES
Profiles may be used to configure compiler options such as optimization
levels and debug settings. See the reference
<https://doc.rust-lang.org/cargo/reference/profiles.html> for more
details.
Profile selection depends on the target and crate being built. By
default the dev or test profiles are used. If the --release flag is
given, then the release or bench profiles are used.
+----------------------------------------+-------------+--------------+
| Target | Default | --release |
| | Profile | Profile |
+----------------------------------------+-------------+--------------+
| lib, bin, example | dev | release |
+----------------------------------------+-------------+--------------+
| test, bench, or any target in "test" | test | bench |
| or "bench" mode | | |
+----------------------------------------+-------------+--------------+
Dependencies use the dev/release profiles.
Unit tests are separate executable artifacts which use the test/bench
profiles. Example targets are built the same as with cargo build (using
the dev/release profiles) unless you are building them with the test
harness (by setting test = true in the manifest or using the --example
flag) in which case they use the test/bench profiles. Library targets
are built with the dev/release profiles when linked to an integration
test, binary, or doctest.
ENVIRONMENT
See the reference
<https://doc.rust-lang.org/cargo/reference/environment-variables.html>
for details on environment variables that Cargo reads.
EXIT STATUS
o 0: Cargo succeeded.
o 101: Cargo failed to complete.
EXAMPLES
1. Execute all the unit and integration tests of the current package:
cargo test
2. Run only tests whose names match against a filter string:
cargo test name_filter
3. Run only a specific test within a specific integration test:
cargo test --test int_test_name -- modname::test_name
SEE ALSO
cargo(1), cargo-bench(1)