libtest: Rename test option --nocapture to --no-capture

Rust's built-in unit testing framework supports not capturing the output
of tests. The current flag `--nocapture` is inconsistent with the other
long name options, i.e., they are written in spinal-case (a.k.a.
kebab-case).

Codegen options `no-prepopulate-passes`, `no-vectorize-loops`,
`no-vectorize-slp`, `no-integrated-as`, and `no-redzone` are hyphenated
between "no" and the name. Cargo has `--no-default-features` and
`--no-deps`.

This change renames the test option `--nocapture` to `--no-capture` to
be consistent with Rust's naming of long name options. The ENV variable
`RUST_TEST_NOCAPTURE` is also renamed to `RUST_TEST_NO_CAPTURE`.

Because this is a public facing option, it is a [breaking-change].

man/rustc.1

@@ -253,8 +253,8 @@ The test framework Rust provides executes tests in parallel. This variable sets
 the maximum number of threads used for this purpose.
 
 .TP
-\fBRUST_TEST_NOCAPTURE\fR
-A synonym for the --nocapture flag.
+\fBRUST_TEST_NO_CAPTURE\fR
+A synonym for the --no-capture flag.
 
 .TP
 \fBRUST_MIN_STACK\fR

src/compiletest/compiletest.rs

@@ -270,7 +270,7 @@ pub fn test_opts(config: &Config) -> test::TestOpts {
         logfile: config.logfile.clone(),
         run_tests: true,
         bench_benchmarks: true,
-        nocapture: env::var("RUST_TEST_NOCAPTURE").is_ok(),
+        no_capture: env::var("RUST_TEST_NO_CAPTURE").is_ok(),
         color: test::AutoColor,
     }
 }

src/compiletest/header.rs

@@ -131,7 +131,7 @@ pub fn load_props(testfile: &Path) -> TestProps {
         true
     });
 
-    for key in vec!["RUST_TEST_NOCAPTURE", "RUST_TEST_THREADS"] {
+    for key in vec!["RUST_TEST_NO_CAPTURE", "RUST_TEST_THREADS"] {
         match env::var(key) {
             Ok(val) =>
                 if exec_env.iter().find(|&&(ref x, _)| *x == key.to_string()).is_none() {

src/libtest/lib.rs

@@ -287,7 +287,7 @@ pub struct TestOpts {
     pub run_tests: bool,
     pub bench_benchmarks: bool,
     pub logfile: Option<PathBuf>,
-    pub nocapture: bool,
+    pub no_capture: bool,
     pub color: ColorConfig,
 }
 
@@ -300,7 +300,7 @@ impl TestOpts {
             run_tests: false,
             bench_benchmarks: false,
             logfile: None,
-            nocapture: false,
+            no_capture: false,
             color: AutoColor,
         }
     }
@@ -316,7 +316,7 @@ fn optgroups() -> Vec<getopts::OptGroup> {
       getopts::optflag("h", "help", "Display this message (longer with --help)"),
       getopts::optopt("", "logfile", "Write logs to the specified file instead \
                           of stdout", "PATH"),
-      getopts::optflag("", "nocapture", "don't capture stdout/stderr of each \
+      getopts::optflag("", "no-capture", "don't capture stdout/stderr of each \
                                          task, allow printing directly"),
       getopts::optopt("", "color", "Configure coloring of output:
             auto   = colorize if stdout is a tty and tests are run on serially (default);
@@ -335,7 +335,7 @@ By default, all tests are run in parallel. This can be altered with 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 the RUST_TEST_NOCAPTURE=1
+This can be overridden with the --no-capture flag or the RUST_TEST_NO_CAPTURE=1
 environment variable. Logging is not captured by default.
 
 Test Attributes:
@@ -381,9 +381,9 @@ pub fn parse_opts(args: &[String]) -> Option<OptRes> {
     let run_tests = ! bench_benchmarks ||
         matches.opt_present("test");
 
-    let mut nocapture = matches.opt_present("nocapture");
-    if !nocapture {
-        nocapture = env::var("RUST_TEST_NOCAPTURE").is_ok();
+    let mut no_capture = matches.opt_present("no-capture");
+    if !no_capture {
+        no_capture = env::var("RUST_TEST_NO_CAPTURE").is_ok();
     }
 
     let color = match matches.opt_str("color").as_ref().map(|s| &**s) {
@@ -402,7 +402,7 @@ pub fn parse_opts(args: &[String]) -> Option<OptRes> {
         run_tests: run_tests,
         bench_benchmarks: bench_benchmarks,
         logfile: logfile,
-        nocapture: nocapture,
+        no_capture: no_capture,
         color: color,
     };
 
@@ -929,7 +929,7 @@ pub fn run_test(opts: &TestOpts,
 
     fn run_test_inner(desc: TestDesc,
                       monitor_ch: Sender<MonitorMsg>,
-                      nocapture: bool,
+                      no_capture: bool,
                       testfn: Thunk<'static>) {
         struct Sink(Arc<Mutex<Vec<u8>>>);
         impl Write for Sink {
@@ -948,7 +948,7 @@ pub fn run_test(opts: &TestOpts,
             });
 
             let result_guard = cfg.spawn(move || {
-                if !nocapture {
+                if !no_capture {
                     io::set_print(box Sink(data2.clone()));
                     io::set_panic(box Sink(data2));
                 }
@@ -983,8 +983,8 @@ pub fn run_test(opts: &TestOpts,
             monitor_ch.send((desc, TrMetrics(mm), Vec::new())).unwrap();
             return;
         }
-        DynTestFn(f) => run_test_inner(desc, monitor_ch, opts.nocapture, f),
-        StaticTestFn(f) => run_test_inner(desc, monitor_ch, opts.nocapture,
+        DynTestFn(f) => run_test_inner(desc, monitor_ch, opts.no_capture, f),
+        StaticTestFn(f) => run_test_inner(desc, monitor_ch, opts.no_capture,
                                           Box::new(move|| f()))
     }
 }