Create a hacky fail-fast mode that stops tests at the first failure

Author: oli-obk

library/test/src/cli.rs

@@ -26,6 +26,10 @@ pub struct TestOpts {
     pub test_threads: Option<usize>,
     pub skip: Vec<String>,
     pub time_options: Option<TestTimeOptions>,
+    /// Stop at first failing test.
+    /// May run a few more tests due to threading, but will
+    /// abort as soon as possible.
+    pub fail_fast: bool,
     pub options: Options,
 }
 
@@ -296,6 +300,7 @@ fn parse_opts_impl(matches: getopts::Matches) -> OptRes {
         skip,
         time_options,
         options,
+        fail_fast: false,
     };
 
     Ok(test_opts)

library/test/src/console.rs

@@ -293,7 +293,7 @@ pub fn run_tests_console(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> io::Resu
     run_tests(opts, tests, |x| on_test_event(&x, &mut st, &mut *out))?;
     st.exec_time = start_time.map(|t| TestSuiteExecTime(t.elapsed()));
 
-    assert!(st.current_test_count() == st.total);
+    assert!(opts.fail_fast || st.current_test_count() == st.total);
 
     out.write_run_finish(&st)
 }

library/test/src/lib.rs

@@ -384,8 +384,17 @@ where
             let mut completed_test = rx.recv().unwrap();
             RunningTest { join_handle }.join(&mut completed_test);
 
+            let fail_fast = match completed_test.result {
+                TrIgnored | TrOk | TrBench(_) => false,
+                TrFailed | TrFailedMsg(_) | TrTimedFail => opts.fail_fast,
+            };
+
             let event = TestEvent::TeResult(completed_test);
             notify_about_test_event(event)?;
+
+            if fail_fast {
+                return Ok(());
+            }
         }
     } else {
         while pending > 0 || !remaining.is_empty() {
@@ -431,9 +440,20 @@ where
             let running_test = running_tests.remove(&completed_test.id).unwrap();
             running_test.join(&mut completed_test);
 
+            let fail_fast = match completed_test.result {
+                TrIgnored | TrOk | TrBench(_) => false,
+                TrFailed | TrFailedMsg(_) | TrTimedFail => opts.fail_fast,
+            };
+
             let event = TestEvent::TeResult(completed_test);
             notify_about_test_event(event)?;
             pending -= 1;
+
+            if fail_fast {
+                // Prevent remaining test threads from panicking
+                std::mem::forget(rx);
+                return Ok(());
+            }
         }
     }
 

library/test/src/tests.rs

@@ -51,6 +51,7 @@ impl TestOpts {
             skip: vec![],
             time_options: None,
             options: Options::new(),
+            fail_fast: false,
         }
     }
 }

src/tools/compiletest/src/main.rs

@@ -514,6 +514,7 @@ pub fn test_opts(config: &Config) -> test::TestOpts {
         options: test::Options::new(),
         time_options: None,
         force_run_in_process: false,
+        fail_fast: std::env::var_os("RUSTC_TEST_FAIL_FAST").is_some(),
     }
 }