cargo test -- --nocapture no longer works.
when I run cargo test -- --help I can still see a nocapture option however when I run cargo test -- --nocapture I get a message saying Found argument '--nocapture' which wasn't expected, or isn't valid in this context
What is your cargo --version?
cargo 1.55.0 (32da73ab1 2021-08-23)
Hmm. Are you using clap in any of your tests?
I am using structopt in my project but in the tests no nothing about clap or structopt
If some of your tests call functions from your library crate that try to parse command-line arguments using clap/structopt, you can run into very similar-looking problems since Cargo passes arguments following -- to the generated test binary. Do you have any tests like that?
the thing is that when I run cargo test -- --help I get proper output of a test binary rather than my app however --nocapture doenst get passed to the test binary like --help does
Could you post the full error message? (Also, if this code is in a repo somewhere so we can clone and run it ourselves that'd be very useful.)
as you can see below for --help works just as expected while --nocapture or anything else does not also I attached the code just below nothing fancy but as of writing this now I noticed that the flags::get does some parsing 
async fn get_proxy_addr(ip: IpAddr) -> Result<IpAddr>
{
let proxy_api_addr = flags::get().proxy_api_addr;
Ok(Client::new()
.post(proxy_api_addr + "/addr")
.form(&[("body", ip.to_string().as_str())])
.send()
.await?
.text()
.await?
.parse::<IpAddr>()
.map_err(|_| Error::InvalidIpResponse)?)
}
#[cfg(test)]
mod tests {
#[tokio::test]
async fn get_addr(){
let addr = super::get_proxy_addr("127.0.0.1".parse().unwrap()).await;
dbg!(addr).ok();
}
}
~/.p/smm ><> cargo test -- --nocapture
Finished test [unoptimized + debuginfo] target(s) in 0.07s
Running unittests (target/debug/deps/smm-8393c40268822165)
running 1 test
error: Found argument '--nocapture' which wasn't expected, or isn't valid in this context
USAGE:
smm-8393c40268822165 [OPTIONS]
For more information try --help
error: test failed, to rerun pass '--lib'
~/.p/smm ><> cargo test -- --help
Finished test [unoptimized + debuginfo] target(s) in 0.06s
Running unittests (target/debug/deps/smm-8393c40268822165)
Usage: --help [OPTIONS] [FILTERS...]
Options:
--include-ignored
Run ignored and not ignored tests
--ignored Run only ignored tests
--force-run-in-process
Forces tests to run in-process when panic=abort
--exclude-should-panic
Excludes tests marked as should_panic
--test Run tests and not benchmarks
--bench Run benchmarks instead of tests
--list List all tests and benchmarks
-h, --help Display this message
--logfile PATH Write logs to the specified file
--nocapture don't capture stdout/stderr of each task, allow
printing directly
--test-threads n_threads
Number of threads used for running tests in parallel
--skip FILTER Skip tests whose names contain FILTER (this flag can
be used multiple times)
-q, --quiet Display one character per test instead of one line.
Alias to --format=terse
--exact Exactly match filters rather than by substring
--color auto|always|never
Configure coloring of output:
auto = colorize if stdout is a tty and tests are run
on serially (default);
always = always colorize output;
never = never colorize output;
--format pretty|terse|json|junit
Configure formatting of output:
pretty = Print verbose output;
terse = Display one character per test;
json = Output a json document;
junit = Output a JUnit document
--show-output Show captured stdout of successful tests
-Z unstable-options Enable nightly-only flags:
unstable-options = Allow use of experimental features
--report-time [plain|colored]
Show execution time of each test. Available values:
plain = do not colorize the execution time (default);
colored = colorize output according to the `color`
parameter value;
Threshold values for colorized output can be
configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
Durations must be specified in milliseconds, e.g.
`500,2000` means that the warn time
is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse
--ensure-time Treat excess of the test execution time limit as
error.
Threshold values for this option can be configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
`CRITICAL_TIME` here means the limit that should not
be exceeded by test.
The FILTER string is tested against the name of all tests, and only those
tests whose names contain the filter are run. Multiple filter strings may
be passed, which will run all tests matching any of the filters.
By default, all tests are run in parallel. This can be altered with the
--test-threads flag or the RUST_TEST_THREADS environment variable when running
tests (set it to 1).
All tests have their standard output and standard error captured by default.
This can be overridden with the --nocapture flag or setting RUST_TEST_NOCAPTURE
environment variable to a value other than "0". Logging is not captured by default.
Test Attributes:
`#[test]` - Indicates a function is a test to be run. This function
takes no arguments.
`#[bench]` - Indicates a function is a benchmark to be run. This
function takes one argument (test::Bencher).
`#[should_panic]` - This function (also labeled with `#[test]`) will only pass if
the code causes a panic (an assertion failure or panic!)
A message may be provided, which the failure string must
contain: #[should_panic(expected = "foo")].
`#[ignore]` - When applied to a function which is already attributed as a
test, then the test runner will ignore these tests during
normal test runs. Running with --ignored or --include-ignored will run
these tests.
Running unittests (target/debug/deps/gen_passwd-8f0c5cdd8063def0)
Usage: --help [OPTIONS] [FILTERS...]
Options:
--include-ignored
Run ignored and not ignored tests
--ignored Run only ignored tests
--force-run-in-process
Forces tests to run in-process when panic=abort
--exclude-should-panic
Excludes tests marked as should_panic
--test Run tests and not benchmarks
--bench Run benchmarks instead of tests
--list List all tests and benchmarks
-h, --help Display this message
--logfile PATH Write logs to the specified file
--nocapture don't capture stdout/stderr of each task, allow
printing directly
--test-threads n_threads
Number of threads used for running tests in parallel
--skip FILTER Skip tests whose names contain FILTER (this flag can
be used multiple times)
-q, --quiet Display one character per test instead of one line.
Alias to --format=terse
--exact Exactly match filters rather than by substring
--color auto|always|never
Configure coloring of output:
auto = colorize if stdout is a tty and tests are run
on serially (default);
always = always colorize output;
never = never colorize output;
--format pretty|terse|json|junit
Configure formatting of output:
pretty = Print verbose output;
terse = Display one character per test;
json = Output a json document;
junit = Output a JUnit document
--show-output Show captured stdout of successful tests
-Z unstable-options Enable nightly-only flags:
unstable-options = Allow use of experimental features
--report-time [plain|colored]
Show execution time of each test. Available values:
plain = do not colorize the execution time (default);
colored = colorize output according to the `color`
parameter value;
Threshold values for colorized output can be
configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
Durations must be specified in milliseconds, e.g.
`500,2000` means that the warn time
is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse
--ensure-time Treat excess of the test execution time limit as
error.
Threshold values for this option can be configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
`CRITICAL_TIME` here means the limit that should not
be exceeded by test.
The FILTER string is tested against the name of all tests, and only those
tests whose names contain the filter are run. Multiple filter strings may
be passed, which will run all tests matching any of the filters.
By default, all tests are run in parallel. This can be altered with the
--test-threads flag or the RUST_TEST_THREADS environment variable when running
tests (set it to 1).
All tests have their standard output and standard error captured by default.
This can be overridden with the --nocapture flag or setting RUST_TEST_NOCAPTURE
environment variable to a value other than "0". Logging is not captured by default.
Test Attributes:
`#[test]` - Indicates a function is a test to be run. This function
takes no arguments.
`#[bench]` - Indicates a function is a benchmark to be run. This
function takes one argument (test::Bencher).
`#[should_panic]` - This function (also labeled with `#[test]`) will only pass if
the code causes a panic (an assertion failure or panic!)
A message may be provided, which the failure string must
contain: #[should_panic(expected = "foo")].
`#[ignore]` - When applied to a function which is already attributed as a
test, then the test runner will ignore these tests during
normal test runs. Running with --ignored or --include-ignored will run
these tests.
Running unittests (target/debug/deps/sign-12759b9c7d9244fc)
Usage: --help [OPTIONS] [FILTERS...]
Options:
--include-ignored
Run ignored and not ignored tests
--ignored Run only ignored tests
--force-run-in-process
Forces tests to run in-process when panic=abort
--exclude-should-panic
Excludes tests marked as should_panic
--test Run tests and not benchmarks
--bench Run benchmarks instead of tests
--list List all tests and benchmarks
-h, --help Display this message
--logfile PATH Write logs to the specified file
--nocapture don't capture stdout/stderr of each task, allow
printing directly
--test-threads n_threads
Number of threads used for running tests in parallel
--skip FILTER Skip tests whose names contain FILTER (this flag can
be used multiple times)
-q, --quiet Display one character per test instead of one line.
Alias to --format=terse
--exact Exactly match filters rather than by substring
--color auto|always|never
Configure coloring of output:
auto = colorize if stdout is a tty and tests are run
on serially (default);
always = always colorize output;
never = never colorize output;
--format pretty|terse|json|junit
Configure formatting of output:
pretty = Print verbose output;
terse = Display one character per test;
json = Output a json document;
junit = Output a JUnit document
--show-output Show captured stdout of successful tests
-Z unstable-options Enable nightly-only flags:
unstable-options = Allow use of experimental features
--report-time [plain|colored]
Show execution time of each test. Available values:
plain = do not colorize the execution time (default);
colored = colorize output according to the `color`
parameter value;
Threshold values for colorized output can be
configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
Durations must be specified in milliseconds, e.g.
`500,2000` means that the warn time
is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse
--ensure-time Treat excess of the test execution time limit as
error.
Threshold values for this option can be configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
`CRITICAL_TIME` here means the limit that should not
be exceeded by test.
The FILTER string is tested against the name of all tests, and only those
tests whose names contain the filter are run. Multiple filter strings may
be passed, which will run all tests matching any of the filters.
By default, all tests are run in parallel. This can be altered with the
--test-threads flag or the RUST_TEST_THREADS environment variable when running
tests (set it to 1).
All tests have their standard output and standard error captured by default.
This can be overridden with the --nocapture flag or setting RUST_TEST_NOCAPTURE
environment variable to a value other than "0". Logging is not captured by default.
Test Attributes:
`#[test]` - Indicates a function is a test to be run. This function
takes no arguments.
`#[bench]` - Indicates a function is a benchmark to be run. This
function takes one argument (test::Bencher).
`#[should_panic]` - This function (also labeled with `#[test]`) will only pass if
the code causes a panic (an assertion failure or panic!)
A message may be provided, which the failure string must
contain: #[should_panic(expected = "foo")].
`#[ignore]` - When applied to a function which is already attributed as a
test, then the test runner will ignore these tests during
normal test runs. Running with --ignored or --include-ignored will run
these tests.
Running unittests (target/debug/deps/smm-9a5db8737de8d242)
Usage: --help [OPTIONS] [FILTERS...]
Options:
--include-ignored
Run ignored and not ignored tests
--ignored Run only ignored tests
--force-run-in-process
Forces tests to run in-process when panic=abort
--exclude-should-panic
Excludes tests marked as should_panic
--test Run tests and not benchmarks
--bench Run benchmarks instead of tests
--list List all tests and benchmarks
-h, --help Display this message
--logfile PATH Write logs to the specified file
--nocapture don't capture stdout/stderr of each task, allow
printing directly
--test-threads n_threads
Number of threads used for running tests in parallel
--skip FILTER Skip tests whose names contain FILTER (this flag can
be used multiple times)
-q, --quiet Display one character per test instead of one line.
Alias to --format=terse
--exact Exactly match filters rather than by substring
--color auto|always|never
Configure coloring of output:
auto = colorize if stdout is a tty and tests are run
on serially (default);
always = always colorize output;
never = never colorize output;
--format pretty|terse|json|junit
Configure formatting of output:
pretty = Print verbose output;
terse = Display one character per test;
json = Output a json document;
junit = Output a JUnit document
--show-output Show captured stdout of successful tests
-Z unstable-options Enable nightly-only flags:
unstable-options = Allow use of experimental features
--report-time [plain|colored]
Show execution time of each test. Available values:
plain = do not colorize the execution time (default);
colored = colorize output according to the `color`
parameter value;
Threshold values for colorized output can be
configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
Durations must be specified in milliseconds, e.g.
`500,2000` means that the warn time
is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse
--ensure-time Treat excess of the test execution time limit as
error.
Threshold values for this option can be configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
`CRITICAL_TIME` here means the limit that should not
be exceeded by test.
The FILTER string is tested against the name of all tests, and only those
tests whose names contain the filter are run. Multiple filter strings may
be passed, which will run all tests matching any of the filters.
By default, all tests are run in parallel. This can be altered with the
--test-threads flag or the RUST_TEST_THREADS environment variable when running
tests (set it to 1).
All tests have their standard output and standard error captured by default.
This can be overridden with the --nocapture flag or setting RUST_TEST_NOCAPTURE
environment variable to a value other than "0". Logging is not captured by default.
Test Attributes:
`#[test]` - Indicates a function is a test to be run. This function
takes no arguments.
`#[bench]` - Indicates a function is a benchmark to be run. This
function takes one argument (test::Bencher).
`#[should_panic]` - This function (also labeled with `#[test]`) will only pass if
the code causes a panic (an assertion failure or panic!)
A message may be provided, which the failure string must
contain: #[should_panic(expected = "foo")].
`#[ignore]` - When applied to a function which is already attributed as a
test, then the test runner will ignore these tests during
normal test runs. Running with --ignored or --include-ignored will run
these tests.
Doc-tests smm
Usage: --help [OPTIONS] [FILTERS...]
Options:
--include-ignored
Run ignored and not ignored tests
--ignored Run only ignored tests
--force-run-in-process
Forces tests to run in-process when panic=abort
--exclude-should-panic
Excludes tests marked as should_panic
--test Run tests and not benchmarks
--bench Run benchmarks instead of tests
--list List all tests and benchmarks
-h, --help Display this message
--logfile PATH Write logs to the specified file
--nocapture don't capture stdout/stderr of each task, allow
printing directly
--test-threads n_threads
Number of threads used for running tests in parallel
--skip FILTER Skip tests whose names contain FILTER (this flag can
be used multiple times)
-q, --quiet Display one character per test instead of one line.
Alias to --format=terse
--exact Exactly match filters rather than by substring
--color auto|always|never
Configure coloring of output:
auto = colorize if stdout is a tty and tests are run
on serially (default);
always = always colorize output;
never = never colorize output;
--format pretty|terse|json|junit
Configure formatting of output:
pretty = Print verbose output;
terse = Display one character per test;
json = Output a json document;
junit = Output a JUnit document
--show-output Show captured stdout of successful tests
-Z unstable-options Enable nightly-only flags:
unstable-options = Allow use of experimental features
--report-time [plain|colored]
Show execution time of each test. Available values:
plain = do not colorize the execution time (default);
colored = colorize output according to the `color`
parameter value;
Threshold values for colorized output can be
configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
Durations must be specified in milliseconds, e.g.
`500,2000` means that the warn time
is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse
--ensure-time Treat excess of the test execution time limit as
error.
Threshold values for this option can be configured via
`RUST_TEST_TIME_UNIT`, `RUST_TEST_TIME_INTEGRATION`
and
`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is
`VARIABLE=WARN_TIME,CRITICAL_TIME`.
`CRITICAL_TIME` here means the limit that should not
be exceeded by test.
The FILTER string is tested against the name of all tests, and only those
tests whose names contain the filter are run. Multiple filter strings may
be passed, which will run all tests matching any of the filters.
By default, all tests are run in parallel. This can be altered with the
--test-threads flag or the RUST_TEST_THREADS environment variable when running
tests (set it to 1).
All tests have their standard output and standard error captured by default.
This can be overridden with the --nocapture flag or setting RUST_TEST_NOCAPTURE
environment variable to a value other than "0". Logging is not captured by default.
Test Attributes:
`#[test]` - Indicates a function is a test to be run. This function
takes no arguments.
`#[bench]` - Indicates a function is a benchmark to be run. This
function takes one argument (test::Bencher).
`#[should_panic]` - This function (also labeled with `#[test]`) will only pass if
the code causes a panic (an assertion failure or panic!)
A message may be provided, which the failure string must
contain: #[should_panic(expected = "foo")].
`#[ignore]` - When applied to a function which is already attributed as a
test, then the test runner will ignore these tests during
normal test runs. Running with --ignored or --include-ignored will run
these tests.
Yep, it's caused by clap trying to parse the arguments to the test binary. You can tell because the name of the test binary appears in the usage message:
error: Found argument '--nocapture' which wasn't expected, or isn't valid in this context
USAGE:
smm-8393c40268822165 [OPTIONS]
The reason it doesn't happen with --help is (presumably) that the generated main function for the test binary does its own argument parsing, and when it sees --help it prints its message and exits before any of your tests run. With --nocapture it still parses the argument, but then it runs your tests::get_addr, which calls out to clap, which sees --nocapture and bails.
To fix this, you have to parse the arguments from a sequence you provide yourself within the test instead of from the environment, using e.g. StructOpt::from_iter.
1 Like
thanks I see the issue now
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