Per-test settings¶

Nextest supports overriding some settings for subsets of tests, using the filterset and Rust cfg() syntaxes.

Overrides are set via the [[profile.<name>.overrides]] list.

Selecting tests¶

At least one of these fields must be specified:

filter: Filterset expression selecting tests this override applies to.
platform: Host and/or target platforms this override applies to. Either a string, or a map with host and target keys for cross-compiling. See Specifying platforms for more information.

Supported overrides¶

priority 0.9.91: Priority for matching tests; higher values run sooner. A number from -100 to 100, inclusive. Default: 0.
retries: Retry policy for matching tests.
flaky-result 0.9.131: Whether to treat matching flaky tests as passing or failing.
threads-required: Number of threads each matching test reserves from the pool.
test-group: Assigns matching tests to a test group.
slow-timeout: Time after which matching tests are considered slow, plus optional termination policy.
bench.slow-timeout 0.9.117: Time after which matching benchmarks are considered slow, plus optional termination policy. Replaces slow-timeout when running cargo nextest bench.
leak-timeout: Time to wait for child processes to exit after a matching test completes.
success-output and failure-output: When to display output for matching successful and failed tests, respectively.
junit.store-success-output and junit.store-failure-output: Whether to store successful and failed output, respectively, for matching tests in the JUnit XML report.
junit.flaky-fail-status 0.9.131: How matching flaky-fail tests are reported in the JUnit XML report: as "failure" (default) or "success".
default-filter 0.9.84: Replaces default-filter for matching platforms. Requires platform and must not be combined with filter.
run-extra-args 0.9.86: Extra arguments to pass to matching test binaries.

Example¶

Basic example for per-test settings in <code>.config/nextest.toml</code>

[profile.ci]
retries = 1

[[profile.ci.overrides]]
filter = 'test(/\btest_network_/)'
retries = 4

[[profile.ci.overrides]]
platform = 'x86_64-unknown-linux-gnu'
slow-timeout = "5m"

[[profile.ci.overrides]]
filter = 'test(/\btest_filesystem_/)'
platform = { host = 'cfg(target_os = "macos")' }
leak-timeout = "500ms"
success-output = "immediate"

When --profile ci is specified:

for test names that start with test_network_ (including test names like my_module::test_network_), retry tests up to 4 times
on x86_64-unknown-linux-gnu, set a slow timeout of 5 minutes
on macOS hosts, for test names that start with test_filesystem_ (including test names like my_module::test_filesystem_), set a leak timeout of 500 milliseconds, and show success output immediately.

Override precedence¶

Overrides are configured as an ordered list, and are applied in the following order. For a given test T and a given setting S, overrides are applied in the following order:

Command-line arguments and environment variables for S, if specified, take precedence over all overrides. See Hierarchical configuration for more.
If nextest is run with --profile my-profile, the first override within profile.my-profile.overrides that matches T and configures S is applied.
Otherwise, the first override within profile.default.overrides that matches T and configures S is applied.
Otherwise, if nextest is run with --profile my-profile, the global configuration for that profile is applied, if it configures S.
If none of the above conditions apply, the global configuration specified by profile.default is applied.

Precedence is evaluated separately for each override. If a particular override does not configure a setting, it is ignored for that setting.

Example¶

Example for per-test settings in <code>.config/nextest.toml</code>

[profile.default]
retries = 0  # this is the default, so it doesn't need to be specified
slow-timeout = "30s"

[[profile.default.overrides]]
filter = 'package(my-package)'
retries = 2
slow-timeout = "45s"

[profile.ci]
retries = 1
slow-timeout = { period = "15s", terminate-after = 2 }

[[profile.ci.overrides]]
filter = 'package(my-package) and test(/^flaky::/)'
retries = 3

If nextest is run with --retries 5, all tests are retried 5 times. The slow timeout settings are evaluated as listed below.

Otherwise, if nextest is run with --profile ci:

Tests in my-package that begin with flaky:: are retried 3 times, and are run with a slow timeout of 45 seconds.
Other tests in my-package are retried 2 times and are run with a slow timeout of 45 seconds.
All other tests are retried up to one time and are run with a slow-timeout of 15 seconds. Tests that take longer than 30 seconds are terminated.

If nextest is run without --profile:

Tests in my-package are retried 2 times and with a slow timeout of 45 seconds.
Other tests are retried 0 times with a slow timeout of 30 seconds.