Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 169 insertions, 137 deletions

diff --git a/library/test/src/bench.rs b/library/test/src/bench.rs
index 7869ba2c0..23925e6ea 100644
--- a/library/test/src/bench.rs
+++ b/library/test/src/bench.rs
@@ -49,12 +49,12 @@ impl Bencher {
         self.summary = Some(iter(&mut inner));
     }
 
-    pub fn bench<F>(&mut self, mut f: F) -> Option<stats::Summary>
+    pub fn bench<F>(&mut self, mut f: F) -> Result<Option<stats::Summary>, String>
     where
-        F: FnMut(&mut Bencher),
+        F: FnMut(&mut Bencher) -> Result<(), String>,
     {
-        f(self);
-        self.summary
+        let result = f(self);
+        result.map(|_| self.summary)
     }
 }
 
@@ -195,7 +195,7 @@ pub fn benchmark<F>(
     nocapture: bool,
     f: F,
 ) where
-    F: FnMut(&mut Bencher),
+    F: FnMut(&mut Bencher) -> Result<(), String>,
 {
     let mut bs = Bencher { mode: BenchMode::Auto, summary: None, bytes: 0 };
 
@@ -211,14 +211,14 @@ pub fn benchmark<F>(
 
     let test_result = match result {
         //bs.bench(f) {
-        Ok(Some(ns_iter_summ)) => {
+        Ok(Ok(Some(ns_iter_summ))) => {
             let ns_iter = cmp::max(ns_iter_summ.median as u64, 1);
             let mb_s = bs.bytes * 1000 / ns_iter;
 
             let bs = BenchSamples { ns_iter_summ, mb_s: mb_s as usize };
             TestResult::TrBench(bs)
         }
-        Ok(None) => {
+        Ok(Ok(None)) => {
             // iter not called, so no data.
             // FIXME: error in this case?
             let samples: &mut [f64] = &mut [0.0_f64; 1];
@@ -226,6 +226,7 @@ pub fn benchmark<F>(
             TestResult::TrBench(bs)
         }
         Err(_) => TestResult::TrFailed,
+        Ok(Err(_)) => TestResult::TrFailed,
     };
 
     let stdout = data.lock().unwrap().to_vec();
@@ -233,10 +234,10 @@ pub fn benchmark<F>(
     monitor_ch.send(message).unwrap();
 }
 
-pub fn run_once<F>(f: F)
+pub fn run_once<F>(f: F) -> Result<(), String>
 where
-    F: FnMut(&mut Bencher),
+    F: FnMut(&mut Bencher) -> Result<(), String>,
 {
     let mut bs = Bencher { mode: BenchMode::Single, summary: None, bytes: 0 };
-    bs.bench(f);
+    bs.bench(f).map(|_| ())
 }
diff --git a/library/test/src/cli.rs b/library/test/src/cli.rs
index f981b9c49..8be32183f 100644
--- a/library/test/src/cli.rs
+++ b/library/test/src/cli.rs
@@ -3,9 +3,9 @@
 use std::env;
 use std::path::PathBuf;
 
-use super::helpers::isatty;
 use super::options::{ColorConfig, Options, OutputFormat, RunIgnored};
 use super::time::TestTimeOptions;
+use std::io::{self, IsTerminal};
 
 #[derive(Debug)]
 pub struct TestOpts {
@@ -32,7 +32,7 @@ pub struct TestOpts {
 impl TestOpts {
     pub fn use_color(&self) -> bool {
         match self.color {
-            ColorConfig::AutoColor => !self.nocapture && isatty::stdout_isatty(),
+            ColorConfig::AutoColor => !self.nocapture && io::stdout().is_terminal(),
             ColorConfig::AlwaysColor => true,
             ColorConfig::NeverColor => false,
         }
diff --git a/library/test/src/console.rs b/library/test/src/console.rs
index e9dda9896..b1270c272 100644
--- a/library/test/src/console.rs
+++ b/library/test/src/console.rs
@@ -147,7 +147,7 @@ pub fn list_tests_console(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> io::Res
     let mut ntest = 0;
     let mut nbench = 0;
 
-    for test in filter_tests(&opts, tests) {
+    for test in filter_tests(&opts, tests).into_iter() {
         use crate::TestFn::*;
 
         let TestDescAndFn { desc: TestDesc { name, .. }, testfn } = test;
diff --git a/library/test/src/helpers/isatty.rs b/library/test/src/helpers/isatty.rs
deleted file mode 100644
index 874ecc376..000000000
--- a/library/test/src/helpers/isatty.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-//! Helper module which provides a function to test
-//! if stdout is a tty.
-
-cfg_if::cfg_if! {
-    if #[cfg(unix)] {
-        pub fn stdout_isatty() -> bool {
-            unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
-        }
-    } else if #[cfg(windows)] {
-        pub fn stdout_isatty() -> bool {
-            type DWORD = u32;
-            type BOOL = i32;
-            type HANDLE = *mut u8;
-            type LPDWORD = *mut u32;
-            const STD_OUTPUT_HANDLE: DWORD = -11i32 as DWORD;
-            extern "system" {
-                fn GetStdHandle(which: DWORD) -> HANDLE;
-                fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: LPDWORD) -> BOOL;
-            }
-            unsafe {
-                let handle = GetStdHandle(STD_OUTPUT_HANDLE);
-                let mut out = 0;
-                GetConsoleMode(handle, &mut out) != 0
-            }
-        }
-    } else {
-        // FIXME: Implement isatty on SGX
-        pub fn stdout_isatty() -> bool {
-            false
-        }
-    }
-}
diff --git a/library/test/src/helpers/mod.rs b/library/test/src/helpers/mod.rs
index 049cadf86..6f366a911 100644
--- a/library/test/src/helpers/mod.rs
+++ b/library/test/src/helpers/mod.rs
@@ -3,6 +3,5 @@
 
 pub mod concurrency;
 pub mod exit_code;
-pub mod isatty;
 pub mod metrics;
 pub mod shuffle;
diff --git a/library/test/src/lib.rs b/library/test/src/lib.rs
index 3b7193adc..141f16d17 100644
--- a/library/test/src/lib.rs
+++ b/library/test/src/lib.rs
@@ -6,7 +6,8 @@
 //! benchmarks themselves) should be done via the `#[test]` and
 //! `#[bench]` attributes.
 //!
-//! See the [Testing Chapter](../book/ch11-00-testing.html) of the book for more details.
+//! See the [Testing Chapter](../book/ch11-00-testing.html) of the book for more
+//! details.
 
 // Currently, not much of this is meant for users. It is intended to
 // support the simplest interface possible for representing and
@@ -15,10 +16,11 @@
 
 #![unstable(feature = "test", issue = "50297")]
 #![doc(test(attr(deny(warnings))))]
-#![feature(bench_black_box)]
 #![feature(internal_output_capture)]
+#![feature(is_terminal)]
 #![feature(staged_api)]
 #![feature(process_exitcode_internals)]
+#![feature(panic_can_unwind)]
 #![feature(test)]
 
 // Public reexports
@@ -53,6 +55,7 @@ use std::{
     collections::VecDeque,
     env, io,
     io::prelude::Write,
+    mem::ManuallyDrop,
     panic::{self, catch_unwind, AssertUnwindSafe, PanicInfo},
     process::{self, Command, Termination},
     sync::mpsc::{channel, Sender},
@@ -77,6 +80,7 @@ mod types;
 #[cfg(test)]
 mod tests;
 
+use core::any::Any;
 use event::{CompletedTest, TestEvent};
 use helpers::concurrency::get_concurrency;
 use helpers::exit_code::get_exit_code;
@@ -110,6 +114,29 @@ pub fn test_main(args: &[String], tests: Vec<TestDescAndFn>, options: Option<Opt
             process::exit(ERROR_EXIT_CODE);
         }
     } else {
+        if !opts.nocapture {
+            // If we encounter a non-unwinding panic, flush any captured output from the current test,
+            // and stop  capturing output to ensure that the non-unwinding panic message is visible.
+            // We also acquire the locks for both output streams to prevent output from other threads
+            // from interleaving with the panic message or appearing after it.
+            let builtin_panic_hook = panic::take_hook();
+            let hook = Box::new({
+                move |info: &'_ PanicInfo<'_>| {
+                    if !info.can_unwind() {
+                        std::mem::forget(std::io::stderr().lock());
+                        let mut stdout = ManuallyDrop::new(std::io::stdout().lock());
+                        if let Some(captured) = io::set_output_capture(None) {
+                            if let Ok(data) = captured.lock() {
+                                let _ = stdout.write_all(&data);
+                                let _ = stdout.flush();
+                            }
+                        }
+                    }
+                    builtin_panic_hook(info);
+                }
+            });
+            panic::set_hook(hook);
+        }
         match console::run_tests_console(&opts, tests) {
             Ok(true) => {}
             Ok(false) => process::exit(ERROR_EXIT_CODE),
@@ -176,17 +203,20 @@ fn make_owned_test(test: &&TestDescAndFn) -> TestDescAndFn {
     }
 }
 
-/// Invoked when unit tests terminate. Should panic if the unit
-/// Tests is considered a failure. By default, invokes `report()`
-/// and checks for a `0` result.
-pub fn assert_test_result<T: Termination>(result: T) {
+/// Invoked when unit tests terminate. Returns `Result::Err` if the test is
+/// considered a failure. By default, invokes `report() and checks for a `0`
+/// result.
+pub fn assert_test_result<T: Termination>(result: T) -> Result<(), String> {
     let code = result.report().to_i32();
-    assert_eq!(
-        code, 0,
-        "the test returned a termination value with a non-zero status code ({}) \
-         which indicates a failure",
-        code
-    );
+    if code == 0 {
+        Ok(())
+    } else {
+        Err(format!(
+            "the test returned a termination value with a non-zero status code \
+             ({}) which indicates a failure",
+            code
+        ))
+    }
 }
 
 pub fn run_tests<F>(
@@ -242,7 +272,7 @@ where
     let event = TestEvent::TeFiltered(filtered_descs, shuffle_seed);
     notify_about_test_event(event)?;
 
-    let (filtered_tests, filtered_benchs): (Vec<_>, _) = filtered_tests
+    let (mut filtered_tests, filtered_benchs): (Vec<_>, _) = filtered_tests
         .into_iter()
         .enumerate()
         .map(|(i, e)| (TestId(i), e))
@@ -250,12 +280,12 @@ where
 
     let concurrency = opts.test_threads.unwrap_or_else(get_concurrency);
 
-    let mut remaining = filtered_tests;
     if let Some(shuffle_seed) = shuffle_seed {
-        shuffle_tests(shuffle_seed, &mut remaining);
-    } else {
-        remaining.reverse();
+        shuffle_tests(shuffle_seed, &mut filtered_tests);
     }
+    // Store the tests in a VecDeque so we can efficiently remove the first element to run the
+    // tests in the order they were passed (unless shuffled).
+    let mut remaining = VecDeque::from(filtered_tests);
     let mut pending = 0;
 
     let (tx, rx) = channel::<CompletedTest>();
@@ -295,7 +325,7 @@ where
 
     if concurrency == 1 {
         while !remaining.is_empty() {
-            let (id, test) = remaining.pop().unwrap();
+            let (id, test) = remaining.pop_front().unwrap();
             let event = TestEvent::TeWait(test.desc.clone());
             notify_about_test_event(event)?;
             let join_handle =
@@ -309,7 +339,7 @@ where
     } else {
         while pending > 0 || !remaining.is_empty() {
             while pending < concurrency && !remaining.is_empty() {
-                let (id, test) = remaining.pop().unwrap();
+                let (id, test) = remaining.pop_front().unwrap();
                 let timeout = time::get_default_test_timeout();
                 let desc = test.desc.clone();
 
@@ -421,9 +451,6 @@ pub fn filter_tests(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> Vec<TestDescA
         RunIgnored::No => {}
     }
 
-    // Sort the tests alphabetically
-    filtered.sort_by(|t1, t2| t1.desc.name.as_slice().cmp(t2.desc.name.as_slice()));
-
     filtered
 }
 
@@ -479,7 +506,7 @@ pub fn run_test(
         id: TestId,
         desc: TestDesc,
         monitor_ch: Sender<CompletedTest>,
-        testfn: Box<dyn FnOnce() + Send>,
+        testfn: Box<dyn FnOnce() -> Result<(), String> + Send>,
         opts: TestRunOpts,
     ) -> Option<thread::JoinHandle<()>> {
         let concurrency = opts.concurrency;
@@ -568,11 +595,11 @@ pub fn run_test(
 
 /// Fixed frame used to clean the backtrace with `RUST_BACKTRACE=1`.
 #[inline(never)]
-fn __rust_begin_short_backtrace<F: FnOnce()>(f: F) {
-    f();
+fn __rust_begin_short_backtrace<T, F: FnOnce() -> T>(f: F) -> T {
+    let result = f();
 
     // prevent this frame from being tail-call optimised away
-    black_box(());
+    black_box(result)
 }
 
 fn run_test_in_process(
@@ -580,7 +607,7 @@ fn run_test_in_process(
     desc: TestDesc,
     nocapture: bool,
     report_time: bool,
-    testfn: Box<dyn FnOnce() + Send>,
+    testfn: Box<dyn FnOnce() -> Result<(), String> + Send>,
     monitor_ch: Sender<CompletedTest>,
     time_opts: Option<time::TestTimeOptions>,
 ) {
@@ -592,7 +619,7 @@ fn run_test_in_process(
     }
 
     let start = report_time.then(Instant::now);
-    let result = catch_unwind(AssertUnwindSafe(testfn));
+    let result = fold_err(catch_unwind(AssertUnwindSafe(testfn)));
     let exec_time = start.map(|start| {
         let duration = start.elapsed();
         TestExecTime(duration)
@@ -609,6 +636,19 @@ fn run_test_in_process(
     monitor_ch.send(message).unwrap();
 }
 
+fn fold_err<T, E>(
+    result: Result<Result<T, E>, Box<dyn Any + Send>>,
+) -> Result<T, Box<dyn Any + Send>>
+where
+    E: Send + 'static,
+{
+    match result {
+        Ok(Err(e)) => Err(Box::new(e)),
+        Ok(Ok(v)) => Ok(v),
+        Err(e) => Err(e),
+    }
+}
+
 fn spawn_test_subprocess(
     id: TestId,
     desc: TestDesc,
@@ -664,7 +704,10 @@ fn spawn_test_subprocess(
     monitor_ch.send(message).unwrap();
 }
 
-fn run_test_in_spawned_subprocess(desc: TestDesc, testfn: Box<dyn FnOnce() + Send>) -> ! {
+fn run_test_in_spawned_subprocess(
+    desc: TestDesc,
+    testfn: Box<dyn FnOnce() -> Result<(), String> + Send>,
+) -> ! {
     let builtin_panic_hook = panic::take_hook();
     let record_result = Arc::new(move |panic_info: Option<&'_ PanicInfo<'_>>| {
         let test_result = match panic_info {
@@ -690,7 +733,9 @@ fn run_test_in_spawned_subprocess(desc: TestDesc, testfn: Box<dyn FnOnce() + Sen
     });
     let record_result2 = record_result.clone();
     panic::set_hook(Box::new(move |info| record_result2(Some(&info))));
-    testfn();
+    if let Err(message) = testfn() {
+        panic!("{}", message);
+    }
     record_result(None);
     unreachable!("panic=abort callback should have exited the process")
 }
diff --git a/library/test/src/term.rs b/library/test/src/term.rs
index b256ab7b8..a14b0d4f5 100644
--- a/library/test/src/term.rs
+++ b/library/test/src/term.rs
@@ -39,7 +39,7 @@ pub(crate) fn stdout() -> Option<Box<StdoutTerminal>> {
 pub(crate) fn stdout() -> Option<Box<StdoutTerminal>> {
     TerminfoTerminal::new(io::stdout())
         .map(|t| Box::new(t) as Box<StdoutTerminal>)
-        .or_else(|| WinConsole::new(io::stdout()).ok().map(|t| Box::new(t) as Box<StdoutTerminal>))
+        .or_else(|| Some(Box::new(WinConsole::new(io::stdout())) as Box<StdoutTerminal>))
 }
 
 /// Terminal color definitions
diff --git a/library/test/src/term/win.rs b/library/test/src/term/win.rs
index 4bdbd6ee7..55020141a 100644
--- a/library/test/src/term/win.rs
+++ b/library/test/src/term/win.rs
@@ -113,8 +113,7 @@ impl<T: Write + Send + 'static> WinConsole<T> {
         }
     }
 
-    /// Returns `None` whenever the terminal cannot be created for some reason.
-    pub(crate) fn new(out: T) -> io::Result<WinConsole<T>> {
+    pub(crate) fn new(out: T) -> WinConsole<T> {
         use std::mem::MaybeUninit;
 
         let fg;
@@ -132,13 +131,13 @@ impl<T: Write + Send + 'static> WinConsole<T> {
                 bg = color::BLACK;
             }
         }
-        Ok(WinConsole {
+        WinConsole {
             buf: out,
             def_foreground: fg,
             def_background: bg,
             foreground: fg,
             background: bg,
-        })
+        }
     }
 }
 
diff --git a/library/test/src/tests.rs b/library/test/src/tests.rs
index 0b81aff59..b54be64ef 100644
--- a/library/test/src/tests.rs
+++ b/library/test/src/tests.rs
@@ -67,7 +67,7 @@ fn one_ignored_one_unignored_test() -> Vec<TestDescAndFn> {
                 no_run: false,
                 test_type: TestType::Unknown,
             },
-            testfn: DynTestFn(Box::new(move || {})),
+            testfn: DynTestFn(Box::new(move || Ok(()))),
         },
         TestDescAndFn {
             desc: TestDesc {
@@ -79,14 +79,14 @@ fn one_ignored_one_unignored_test() -> Vec<TestDescAndFn> {
                 no_run: false,
                 test_type: TestType::Unknown,
             },
-            testfn: DynTestFn(Box::new(move || {})),
+            testfn: DynTestFn(Box::new(move || Ok(()))),
         },
     ]
 }
 
 #[test]
 pub fn do_not_run_ignored_tests() {
-    fn f() {
+    fn f() -> Result<(), String> {
         panic!();
     }
     let desc = TestDescAndFn {
@@ -109,7 +109,9 @@ pub fn do_not_run_ignored_tests() {
 
 #[test]
 pub fn ignored_tests_result_in_ignored() {
-    fn f() {}
+    fn f() -> Result<(), String> {
+        Ok(())
+    }
     let desc = TestDescAndFn {
         desc: TestDesc {
             name: StaticTestName("whatever"),
@@ -132,7 +134,7 @@ pub fn ignored_tests_result_in_ignored() {
 #[test]
 #[cfg(not(target_os = "emscripten"))]
 fn test_should_panic() {
-    fn f() {
+    fn f() -> Result<(), String> {
         panic!();
     }
     let desc = TestDescAndFn {
@@ -157,7 +159,7 @@ fn test_should_panic() {
 #[test]
 #[cfg(not(target_os = "emscripten"))]
 fn test_should_panic_good_message() {
-    fn f() {
+    fn f() -> Result<(), String> {
         panic!("an error message");
     }
     let desc = TestDescAndFn {
@@ -183,7 +185,7 @@ fn test_should_panic_good_message() {
 #[cfg(not(target_os = "emscripten"))]
 fn test_should_panic_bad_message() {
     use crate::tests::TrFailedMsg;
-    fn f() {
+    fn f() -> Result<(), String> {
         panic!("an error message");
     }
     let expected = "foobar";
@@ -214,7 +216,7 @@ fn test_should_panic_bad_message() {
 fn test_should_panic_non_string_message_type() {
     use crate::tests::TrFailedMsg;
     use std::any::TypeId;
-    fn f() {
+    fn f() -> Result<(), String> {
         std::panic::panic_any(1i32);
     }
     let expected = "foobar";
@@ -249,7 +251,9 @@ fn test_should_panic_but_succeeds() {
     let should_panic_variants = [ShouldPanic::Yes, ShouldPanic::YesWithMessage("error message")];
 
     for &should_panic in should_panic_variants.iter() {
-        fn f() {}
+        fn f() -> Result<(), String> {
+            Ok(())
+        }
         let desc = TestDescAndFn {
             desc: TestDesc {
                 name: StaticTestName("whatever"),
@@ -283,7 +287,9 @@ fn test_should_panic_but_succeeds() {
 }
 
 fn report_time_test_template(report_time: bool) -> Option<TestExecTime> {
-    fn f() {}
+    fn f() -> Result<(), String> {
+        Ok(())
+    }
     let desc = TestDescAndFn {
         desc: TestDesc {
             name: StaticTestName("whatever"),
@@ -318,7 +324,9 @@ fn test_should_report_time() {
 }
 
 fn time_test_failure_template(test_type: TestType) -> TestResult {
-    fn f() {}
+    fn f() -> Result<(), String> {
+        Ok(())
+    }
     let desc = TestDescAndFn {
         desc: TestDesc {
             name: StaticTestName("whatever"),
@@ -480,7 +488,7 @@ pub fn exclude_should_panic_option() {
             no_run: false,
             test_type: TestType::Unknown,
         },
-        testfn: DynTestFn(Box::new(move || {})),
+        testfn: DynTestFn(Box::new(move || Ok(()))),
     });
 
     let filtered = filter_tests(&opts, tests);
@@ -504,7 +512,7 @@ pub fn exact_filter_match() {
                     no_run: false,
                     test_type: TestType::Unknown,
                 },
-                testfn: DynTestFn(Box::new(move || {})),
+                testfn: DynTestFn(Box::new(move || Ok(()))),
             })
             .collect()
     }
@@ -580,7 +588,9 @@ fn sample_tests() -> Vec<TestDescAndFn> {
         "test::run_include_ignored_option".to_string(),
         "test::sort_tests".to_string(),
     ];
-    fn testfn() {}
+    fn testfn() -> Result<(), String> {
+        Ok(())
+    }
     let mut tests = Vec::new();
     for name in &names {
         let test = TestDescAndFn {
@@ -601,33 +611,6 @@ fn sample_tests() -> Vec<TestDescAndFn> {
 }
 
 #[test]
-pub fn sort_tests() {
-    let mut opts = TestOpts::new();
-    opts.run_tests = true;
-
-    let tests = sample_tests();
-    let filtered = filter_tests(&opts, tests);
-
-    let expected = vec![
-        "isize::test_pow".to_string(),
-        "isize::test_to_str".to_string(),
-        "sha1::test".to_string(),
-        "test::do_not_run_ignored_tests".to_string(),
-        "test::filter_for_ignored_option".to_string(),
-        "test::first_free_arg_should_be_a_filter".to_string(),
-        "test::ignored_tests_result_in_ignored".to_string(),
-        "test::parse_ignored_flag".to_string(),
-        "test::parse_include_ignored_flag".to_string(),
-        "test::run_include_ignored_option".to_string(),
-        "test::sort_tests".to_string(),
-    ];
-
-    for (a, b) in expected.iter().zip(filtered) {
-        assert_eq!(*a, b.desc.name.to_string());
-    }
-}
-
-#[test]
 pub fn shuffle_tests() {
     let mut opts = TestOpts::new();
     opts.shuffle = true;
@@ -717,21 +700,26 @@ pub fn test_metricmap_compare() {
 
 #[test]
 pub fn test_bench_once_no_iter() {
-    fn f(_: &mut Bencher) {}
-    bench::run_once(f);
+    fn f(_: &mut Bencher) -> Result<(), String> {
+        Ok(())
+    }
+    bench::run_once(f).unwrap();
 }
 
 #[test]
 pub fn test_bench_once_iter() {
-    fn f(b: &mut Bencher) {
-        b.iter(|| {})
+    fn f(b: &mut Bencher) -> Result<(), String> {
+        b.iter(|| {});
+        Ok(())
     }
-    bench::run_once(f);
+    bench::run_once(f).unwrap();
 }
 
 #[test]
 pub fn test_bench_no_iter() {
-    fn f(_: &mut Bencher) {}
+    fn f(_: &mut Bencher) -> Result<(), String> {
+        Ok(())
+    }
 
     let (tx, rx) = channel();
 
@@ -751,8 +739,9 @@ pub fn test_bench_no_iter() {
 
 #[test]
 pub fn test_bench_iter() {
-    fn f(b: &mut Bencher) {
-        b.iter(|| {})
+    fn f(b: &mut Bencher) -> Result<(), String> {
+        b.iter(|| {});
+        Ok(())
     }
 
     let (tx, rx) = channel();
@@ -821,3 +810,33 @@ fn should_sort_failures_before_printing_them() {
     let bpos = s.find("b").unwrap();
     assert!(apos < bpos);
 }
+
+#[test]
+#[cfg(not(target_os = "emscripten"))]
+fn test_dyn_bench_returning_err_fails_when_run_as_test() {
+    fn f(_: &mut Bencher) -> Result<(), String> {
+        Result::Err("An error".into())
+    }
+    let desc = TestDescAndFn {
+        desc: TestDesc {
+            name: StaticTestName("whatever"),
+            ignore: false,
+            ignore_message: None,
+            should_panic: ShouldPanic::No,
+            compile_fail: false,
+            no_run: false,
+            test_type: TestType::Unknown,
+        },
+        testfn: DynBenchFn(Box::new(f)),
+    };
+    let (tx, rx) = channel();
+    let notify = move |event: TestEvent| {
+        if let TestEvent::TeResult(result) = event {
+            tx.send(result).unwrap();
+        }
+        Ok(())
+    };
+    run_tests(&TestOpts { run_tests: true, ..TestOpts::new() }, vec![desc], notify).unwrap();
+    let result = rx.recv().unwrap().result;
+    assert_eq!(result, TrFailed);
+}
diff --git a/library/test/src/types.rs b/library/test/src/types.rs
index ffb1efe18..888afff79 100644
--- a/library/test/src/types.rs
+++ b/library/test/src/types.rs
@@ -75,14 +75,15 @@ impl fmt::Display for TestName {
 }
 
 // A function that runs a test. If the function returns successfully,
-// the test succeeds; if the function panics then the test fails. We
-// may need to come up with a more clever definition of test in order
-// to support isolation of tests into threads.
+// the test succeeds; if the function panics or returns Result::Err
+// then the test fails. We may need to come up with a more clever
+// definition of test in order to support isolation of tests into
+// threads.
 pub enum TestFn {
-    StaticTestFn(fn()),
-    StaticBenchFn(fn(&mut Bencher)),
-    DynTestFn(Box<dyn FnOnce() + Send>),
-    DynBenchFn(Box<dyn Fn(&mut Bencher) + Send>),
+    StaticTestFn(fn() -> Result<(), String>),
+    StaticBenchFn(fn(&mut Bencher) -> Result<(), String>),
+    DynTestFn(Box<dyn FnOnce() -> Result<(), String> + Send>),
+    DynBenchFn(Box<dyn Fn(&mut Bencher) -> Result<(), String> + Send>),
 }
 
 impl TestFn {