cargo test

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 twodashes (—) are passed to the test binaries and thus to libtest (rustc’sbuilt in unit-test and micro-benchmarking framework). If you’re passingarguments 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 theoutput of cargo test — —help. As an example, this will run all tests withfoo in their name on 3 threads in parallel:

  1. cargo test foo -- --test-threads 3

Tests are built with the —test option to rustc which creates anexecutable with a main function that automatically runs all functionsannotated with the #[test] attribute in multiple threads. #[bench]annotated functions will also be run with one iteration to verify that theyare functional.

The libtest harness may be disabled by setting harness = false in the targetmanifest settings, in which case your code will need to provide its own mainfunction to handle running tests.

Documentation tests are also run by default, which is handled by rustdoc. Itextracts code samples from documentation comments and executes them. See therustdoc book for more information onwriting 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 exitafter the first executable fails. The Rust test harness will run alltests within the executable to completion, this flag only applies tothe executable as a whole.

Package Selection

By default, when no package selection options are given, the packages selecteddepend 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 thenthe workspaces default members are selected, otherwise only the package definedby the manifest will be selected.

The default members of a workspace can be set explicitly with theworkspace.default-members key in the root manifest. If this is not set, avirtual workspace will include all workspace members (equivalent to passing—workspace), and a non-virtual workspace will include only the root crate itself.

  • -pSPEC…​
  • —packageSPEC…​

  • Test only the specified packages. See cargo-pkgid(1) for theSPEC format. This flag may be specified multiple times.

  • —workspace

  • Test all members in the workspace.

  • —all

  • Deprecated alias for —workspace.

  • —excludeSPEC…​

  • 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 thefollowing 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 areavailable)

  • 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 targetin the manifest settings. Setting examples to test = true will build and runthe example as a test. Setting targets to test = false will stop them frombeing tested by default. Target selection options that take a target by nameignore the test flag and will always test the given target.

Doc tests for libraries may be disabled by setting doctest = false for thelibrary in the manifest.

Passing target selection flags will test only thespecified targets.

  • —lib

  • Test the package’s library.

  • —binNAME…​

  • Test the specified binary. This flag may be specified multiple times.

  • —bins

  • Test all binary targets.

  • —exampleNAME…​

  • Test the specified example. This flag may be specified multiple times.

  • —examples

  • Test all example targets.

  • —testNAME…​

  • Test the specified integration test. This flag may be specified multipletimes.

  • —tests

  • Test all targets in test mode that have the test = true manifestflag set. By default this includes the library and binaries built asunittests, and integration tests. Be aware that this will also build anyrequired dependencies, so the lib target may be built twice (once as aunittest, and once as a dependency for binaries, integration tests, etc.).Targets may be enabled or disabled by setting the test flag in themanifest settings for the target.

  • —benchNAME…​

  • Test the specified benchmark. This flag may be specified multiple times.

  • —benches

  • Test all targets in benchmark mode that have the bench = truemanifest flag set. By default this includes the library and binaries builtas benchmarks, and bench targets. Be aware that this will also build anyrequired dependencies, so the lib target may be built twice (once as abenchmark, and once as a dependency for binaries, benchmarks, etc.).Targets may be enabled or disabled by setting the bench flag in themanifest 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 othertarget options.

Feature Selection

When no feature options are given, the default feature is activated forevery selected package.

  • —featuresFEATURES

  • Space or comma separated list of features to activate. These features onlyapply to the current directory’s package. Features of direct dependenciesmay be enabled with <dep-name>/<feature-name> syntax.

  • —all-features

  • Activate all available features of all selected packages.

  • —no-default-features

  • Do not activate the default feature of the current directory’spackage.

Compilation Options

  • —targetTRIPLE
  • Test for the given architecture. The default is the hostarchitecture. The general format of the triple is<arch><sub>-<vendor>-<sys>-<abi>. Run rustc —print target-list for alist of supported targets.

This may also be specified with the build.targetconfig value.

  • —release
  • Test optimized artifacts with the release profile. See thePROFILES section for details on how this affects profile selection.

Output Options

  • —target-dirDIRECTORY
  • Directory for all generated artifacts and intermediate files. May also bespecified with the CARGO_TARGET_DIR environment variable, or thebuild.target-dir config value. Defaultsto target in the root of the workspace.

Display Options

By default the Rust test harness hides output from test execution to keepresults readable. Test output can be recovered (e.g., for debugging) by passing—nocapture to the test binaries:

  1. cargo test -- --nocapture
  • -v
  • —verbose

  • Use verbose output. May be specified twice for "very verbose" output whichincludes extra output such as dependency warnings and build script output.May also be specified with the term.verboseconfig value.

  • -q

  • —quiet

  • No output printed to stdout.

  • —colorWHEN

  • Control when colored output is used. Valid values:

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

  • always: Always display colors.

  • never: Never display colors.

May also be specified with the term.colorconfig value.

  • —message-formatFMT
  • The output format for diagnostic messages. Can be specified multiple timesand consists of comma-separated values. Valid values:

  • human (default): Display in a human-readable text format.

  • short: Emit shorter, human-readable text messages.

  • json: Emit JSON messages to stdout.

  • json-diagnostic-short: Ensure the rendered field of JSON messages containsthe "short" rendering from rustc.

  • json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messagescontains embedded ANSI color codes for respecting rustc’s default colorscheme.

  • json-render-diagnostics: Instruct Cargo to not include rustc diagnostics inin JSON messages printed, but instead Cargo itself should render theJSON diagnostics coming from rustc. Cargo’s own JSON diagnostics and otherscoming from rustc are still emitted.

Manifest Options

  • —manifest-pathPATH

  • Path to the Cargo.toml file. By default, Cargo searches in the currentdirectory or any parent directory for the Cargo.toml file.

  • —frozen

  • —locked
  • Either of these flags requires that the Cargo.lock file isup-to-date. If the lock file is missing, or it needs to be updated, Cargo willexit with an error. The —frozen flag also prevents Cargo fromattempting to access the network to determine if it is out-of-date.

These may be used in environments where you want to assert that theCargo.lock file is up-to-date (such as a CI build) or want to avoid networkaccess.

  • —offline
  • Prevents Cargo from accessing the network for any reason. Without thisflag, Cargo will stop with an error if it needs to access the network andthe network is not available. With this flag, Cargo will attempt toproceed without the network if possible.

Beware that this may result in different dependency resolution than onlinemode. Cargo will restrict itself to crates that are downloaded locally, evenif 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 goingoffline.

May also be specified with the net.offline config value.

Common Options

  • -h
  • —help

  • Prints help information.

  • -ZFLAG…​

  • Unstable (nightly-only) flags to Cargo. Run cargo -Z help fordetails.

Miscellaneous Options

The —jobs argument affects the building of the test executable but does notaffect how many threads are used when running the tests. The Rust test harnessincludes an option to control the number of threads used:

  1. cargo test -j 2 -- --test-threads=2
  • -jN
  • —jobsN
  • Number of parallel jobs to run. May also be specified with thebuild.jobs config value. Defaults tothe number of CPUs.

PROFILES

Profiles may be used to configure compiler options such as optimization levelsand debug settings. Seethe referencefor more details.

Profile selection depends on the target and crate being built. By default thedev or test profiles are used. If the —release flag is given, then therelease or bench profiles are used.

TargetDefault Profile—release Profile
lib, bin, exampledevrelease
test, bench, or any target in "test" or "bench" modetestbench

Dependencies use the dev/release profiles.

Unit tests are separate executable artifacts which use the test/benchprofiles. Example targets are built the same as with cargo build (using thedev/release profiles) unless you are building them with the test harness(by setting test = true in the manifest or using the —example flag) inwhich case they use the test/bench profiles. Library targets are builtwith the dev/release profiles when linked to an integration test, binary,or doctest.

ENVIRONMENT

See the reference fordetails on environment variables that Cargo reads.

Exit Status

  • 0

  • Cargo succeeded.

  • 101

  • Cargo failed to complete.

EXAMPLES

  • Execute all the unit and integration tests of the current package:
  1. cargo test
  • Run only a specific test within a specific integration test:
  1. cargo test --test int_test_name -- modname::test_name

SEE ALSO

cargo(1), cargo-bench(1)