Ubuntu Manpage: cargo-test — Execute unit and integration tests of a package

Provided by: cargo-1.79_1.79.0+dfsg1ubuntu1~bpo0-0ubuntu0.20.04.1_amd64

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
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 and supports 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 pattern.

--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 and supports 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 pattern.

Target Selection
When no target selection options are given, cargo test will build the following targets of the selected
packages:

• lib — used to link with binaries, examples, integration tests, and doc tests

• bins (only if integration tests are built and required features are available)

• examples — to ensure they compile

• lib as a unit test

• bins as unit tests

• integration tests

• 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, 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
Test the package’s library.

--bin name…
Test the specified binary. This flag may be specified multiple times and supports common Unix glob
patterns.

--bins
Test all binary targets.

--example name…
Test the specified example. This flag may be specified multiple times and supports common Unix glob
patterns.

--examples
Test all example targets.

--test name…
Test the specified integration test. This flag may be specified multiple times and supports common
Unix glob patterns.

--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 and supports common Unix glob
patterns.

--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 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
Space or comma separated list of features to activate. Features of workspace members may be enabled
with package-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 selected packages.

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 flag may be specified multiple times.

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
Test optimized artifacts with the release profile. See also the --profile option for choosing a
specific profile by name.

--profile name
Test with the given profile. See the reference
<https://doc.rust-lang.org/cargo/reference/profiles.html> for more details on profiles.

--timings=fmts
Output information how long each compilation takes, and track concurrency information over time.
Accepts an optional comma-separated list of output formats; --timings without an argument will
default to --timings=html. Specifying an output format (rather than the default) is unstable and
requires -Zunstable-options. Valid output formats:

• html (unstable, requires -Zunstable-options): Write a human-readable file cargo-timing.html to the
target/cargo-timings directory with a report of the compilation. Also write a report to the same
directory with a timestamp in the filename if you want to look at older runs. HTML output is
suitable for human consumption only, and does not provide machine-readable timing data.

• json (unstable, requires -Zunstable-options): Emit machine-readable JSON information about timing
information.

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
Do not print cargo log messages. May also be specified with the term.quiet config value
<https://doc.rust-lang.org/cargo/reference/config.html>.

--color when
Control when colored output is used. Valid values:

• auto (default): Automatically detect if color support is available on the terminal.

• always: Always display colors.

• 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:

• human (default): Display in a human-readable text format. Conflicts with short and json.

• short: Emit shorter, human-readable text messages. Conflicts with human and json.

• json: Emit JSON messages to stdout. See the reference
<https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages> for more details.
Conflicts with human and short.

• json-diagnostic-short: Ensure the rendered field of JSON messages contains the “short” rendering
from rustc. Cannot be used with human or short.

• json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messages contains embedded ANSI
color codes for respecting rustc’s default color scheme. Cannot be used with human or short.

• json-render-diagnostics: Instruct Cargo to not include rustc diagnostics 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. Cannot be used with human or short.

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.

--ignore-rust-version
Ignore rust-version specification in packages.

--locked
Asserts that the exact same dependencies and versions are used as when the existing Cargo.lock file
was originally generated. Cargo will exit with an error when either of the following scenarios
arises:

• The lock file is missing.

• Cargo attempted to change the lock file due to a different dependency resolution.

It may be used in environments where deterministic builds are desired, such as in CI pipelines.

--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>.

--frozen
Equivalent to specifying both --locked and --offline.

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.

--config KEY=VALUE or PATH
Overrides a Cargo configuration value. The argument should be in TOML syntax of KEY=VALUE, or
provided as a path to an extra configuration file. This flag may be specified multiple times. See the
command-line overrides section
<https://doc.rust-lang.org/cargo/reference/config.html#command-line-overrides> for more information.

-C PATH
Changes the current working directory before executing any specified operations. This affects things
like where cargo looks by default for the project manifest (Cargo.toml), as well as the directories
searched for discovering .cargo/config.toml, for example. This option must appear before the command
name, for example cargo -C path/to/my-project build.

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
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 logical CPUs. If
negative, it sets the maximum number of parallel jobs to the number of logical CPUs plus provided
value. If a string default is provided, it sets the value back to defaults. Should not be 0.

--future-incompat-report
Displays a future-incompat report for any future-incompatible warnings produced during execution of
this command

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

       •  0: Cargo succeeded.

       •  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