Respect --nocapture in panic=abort test mode

Author: tmandry

src/libtest/lib.rs

@@ -63,8 +63,7 @@ use std::{
     env, io,
     io::prelude::Write,
     panic::{self, catch_unwind, AssertUnwindSafe, PanicInfo},
-    process,
-    process::{Command, Termination},
+    process::{self, Command, Termination},
     sync::mpsc::{channel, Sender},
     sync::{Arc, Mutex},
     thread,
@@ -457,9 +456,13 @@ pub fn run_test(
                 monitor_ch,
                 opts.time,
             ),
-            RunStrategy::SpawnPrimary => {
-                spawn_test_subprocess(desc, opts.time.is_some(), monitor_ch, opts.time)
-            }
+            RunStrategy::SpawnPrimary => spawn_test_subprocess(
+                desc,
+                opts.nocapture,
+                opts.time.is_some(),
+                monitor_ch,
+                opts.time,
+            ),
         };
 
         // If the platform is single-threaded we're just going to run
@@ -558,6 +561,7 @@ fn run_test_in_process(
 
 fn spawn_test_subprocess(
     desc: TestDesc,
+    nocapture: bool,
     report_time: bool,
     monitor_ch: Sender<CompletedTest>,
     time_opts: Option<time::TestTimeOptions>,
@@ -566,11 +570,15 @@ fn spawn_test_subprocess(
         let args = env::args().collect::<Vec<_>>();
         let current_exe = &args[0];
 
+        let mut command = Command::new(current_exe);
+        command.env(SECONDARY_TEST_INVOKER_VAR, desc.name.as_slice());
+        if nocapture {
+            command.stdout(process::Stdio::inherit());
+            command.stderr(process::Stdio::inherit());
+        }
+
         let start = report_time.then(Instant::now);
-        let output = match Command::new(current_exe)
-            .env(SECONDARY_TEST_INVOKER_VAR, desc.name.as_slice())
-            .output()
-        {
+        let output = match command.output() {
             Ok(out) => out,
             Err(e) => {
                 let err = format!("Failed to spawn {} as child for test: {:?}", args[0], e);

src/test/ui/test-panic-abort-nocapture.rs

@@ -0,0 +1,39 @@
+// no-prefer-dynamic
+// compile-flags: --test -Cpanic=abort -Zpanic_abort_tests
+// run-flags: --test-threads=1 --nocapture
+// run-fail
+// check-run-results
+// exec-env:RUST_BACKTRACE=0
+
+// ignore-wasm no panic or subprocess support
+// ignore-emscripten no panic or subprocess support
+
+#![cfg(test)]
+
+use std::io::Write;
+
+#[test]
+fn it_works() {
+    println!("about to succeed");
+    assert_eq!(1 + 1, 2);
+}
+
+#[test]
+#[should_panic]
+fn it_panics() {
+    println!("about to panic");
+    assert_eq!(1 + 1, 4);
+}
+
+#[test]
+fn it_fails() {
+    println!("about to fail");
+    assert_eq!(1 + 1, 4);
+}
+
+#[test]
+fn it_writes_to_stdio() {
+    println!("hello, world");
+    writeln!(std::io::stdout(), "testing123").unwrap();
+    writeln!(std::io::stderr(), "testing321").unwrap();
+}

src/test/ui/test-panic-abort-nocapture.run.stderr

@@ -0,0 +1,9 @@
+thread 'main' panicked at 'assertion failed: `(left == right)`
+  left: `2`,
+ right: `4`', $DIR/test-panic-abort-nocapture.rs:31:5
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+thread 'main' panicked at 'assertion failed: `(left == right)`
+  left: `2`,
+ right: `4`', $DIR/test-panic-abort-nocapture.rs:25:5
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+testing321

src/test/ui/test-panic-abort-nocapture.run.stdout

@@ -0,0 +1,23 @@
+
+running 4 tests
+test it_fails ... about to fail
+FAILED
+test it_panics ... about to panic
+ok
+test it_works ... about to succeed
+ok
+test it_writes_to_stdio ... hello, world
+testing123
+ok
+
+failures:
+
+---- it_fails stdout ----
+---- it_fails stderr ----
+
+
+failures:
+    it_fails
+
+test result: FAILED. 3 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
+