Auto merge of #38181 - jsgf:test-filter-exact, r=alexcrichton

libtest: add --exact to make filter matching exact

Filter matching is by substring by default. This makes it impossible
to run a single test if its name is a substring of some other test.
For example, its not possible to run just `mymod::test` with these
tests:

```
  mymod::test
  mymod::test1
  mymod::test_module::moretests
```

You could declare by convention that no test has a name that's a
substring of another test, but that's not really practical.

This PR adds the `--exact` flag, to make filter matching exactly
match the complete name.

src/libtest/lib.rs

@@ -301,6 +301,7 @@ pub enum ColorConfig {
 
 pub struct TestOpts {
     pub filter: Option<String>,
+    pub filter_exact: bool,
     pub run_ignored: bool,
     pub run_tests: bool,
     pub bench_benchmarks: bool,
@@ -317,6 +318,7 @@ impl TestOpts {
     fn new() -> TestOpts {
         TestOpts {
             filter: None,
+            filter_exact: false,
             run_ignored: false,
             run_tests: false,
             bench_benchmarks: false,
@@ -348,6 +350,7 @@ fn optgroups() -> Vec<getopts::OptGroup> {
       getopts::optmulti("", "skip", "Skip tests whose names contain FILTER (this flag can \
                                      be used multiple times)","FILTER"),
       getopts::optflag("q", "quiet", "Display one character per test instead of one line"),
+      getopts::optflag("", "exact", "Exactly match filters rather than by substring"),
       getopts::optopt("", "color", "Configure coloring of output:
             auto   = colorize if stdout is a tty and tests are run on serially (default);
             always = always colorize output;
@@ -407,6 +410,7 @@ pub fn parse_opts(args: &[String]) -> Option<OptRes> {
 
     let run_ignored = matches.opt_present("ignored");
     let quiet = matches.opt_present("quiet");
+    let exact = matches.opt_present("exact");
 
     let logfile = matches.opt_str("logfile");
     let logfile = logfile.map(|s| PathBuf::from(&s));
@@ -448,6 +452,7 @@ pub fn parse_opts(args: &[String]) -> Option<OptRes> {
 
     let test_opts = TestOpts {
         filter: filter,
+        filter_exact: exact,
         run_ignored: run_ignored,
         run_tests: run_tests,
         bench_benchmarks: bench_benchmarks,
@@ -1118,14 +1123,26 @@ pub fn filter_tests(opts: &TestOpts, tests: Vec<TestDescAndFn>) -> Vec<TestDescA
         None => filtered,
         Some(ref filter) => {
             filtered.into_iter()
-                    .filter(|test| test.desc.name.as_slice().contains(&filter[..]))
+                    .filter(|test| {
+                        if opts.filter_exact {
+                            test.desc.name.as_slice() == &filter[..]
+                        } else {
+                            test.desc.name.as_slice().contains(&filter[..])
+                        }
+                    })
                     .collect()
         }
     };
 
     // Skip tests that match any of the skip filters
     filtered = filtered.into_iter()
-        .filter(|t| !opts.skip.iter().any(|sf| t.desc.name.as_slice().contains(&sf[..])))
+        .filter(|t| !opts.skip.iter().any(|sf| {
+                if opts.filter_exact {
+                    t.desc.name.as_slice() == &sf[..]
+                } else {
+                    t.desc.name.as_slice().contains(&sf[..])
+                }
+            }))
         .collect();
 
     // Maybe pull out the ignored test and unignore them
@@ -1654,6 +1671,77 @@ mod tests {
         assert!(!filtered[0].desc.ignore);
     }
 
+    #[test]
+    pub fn exact_filter_match() {
+        fn tests() -> Vec<TestDescAndFn> {
+            vec!["base",
+                 "base::test",
+                 "base::test1",
+                 "base::test2",
+            ].into_iter()
+            .map(|name| TestDescAndFn {
+                desc: TestDesc {
+                    name: StaticTestName(name),
+                    ignore: false,
+                    should_panic: ShouldPanic::No,
+                },
+                testfn: DynTestFn(Box::new(move |()| {}))
+            })
+            .collect()
+        }
+
+        let substr = filter_tests(&TestOpts {
+                filter: Some("base".into()),
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(substr.len(), 4);
+
+        let substr = filter_tests(&TestOpts {
+                filter: Some("bas".into()),
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(substr.len(), 4);
+
+        let substr = filter_tests(&TestOpts {
+                filter: Some("::test".into()),
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(substr.len(), 3);
+
+        let substr = filter_tests(&TestOpts {
+                filter: Some("base::test".into()),
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(substr.len(), 3);
+
+        let exact = filter_tests(&TestOpts {
+                filter: Some("base".into()),
+                filter_exact: true, ..TestOpts::new()
+            }, tests());
+        assert_eq!(exact.len(), 1);
+
+        let exact = filter_tests(&TestOpts {
+                filter: Some("bas".into()),
+                filter_exact: true,
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(exact.len(), 0);
+
+        let exact = filter_tests(&TestOpts {
+                filter: Some("::test".into()),
+                filter_exact: true,
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(exact.len(), 0);
+
+        let exact = filter_tests(&TestOpts {
+                filter: Some("base::test".into()),
+                filter_exact: true,
+                ..TestOpts::new()
+            }, tests());
+        assert_eq!(exact.len(), 1);
+    }
+
     #[test]
     pub fn sort_tests() {
         let mut opts = TestOpts::new();

src/tools/compiletest/src/common.rs

@@ -127,6 +127,9 @@ pub struct Config {
     // Only run tests that match this filter
     pub filter: Option<String>,
 
+    // Exactly match the filter, rather than a substring
+    pub filter_exact: bool,
+
     // Write out a parseable log of tests that were run
     pub logfile: Option<PathBuf>,
 

src/tools/compiletest/src/main.rs

@@ -89,6 +89,7 @@ pub fn parse_config(args: Vec<String> ) -> Config {
                  "(compile-fail|parse-fail|run-fail|run-pass|\
                   run-pass-valgrind|pretty|debug-info|incremental|mir-opt)"),
           optflag("", "ignored", "run tests marked as ignored"),
+          optflag("", "exact", "filters match exactly"),
           optopt("", "runtool", "supervisor program to run tests under \
                                  (eg. emulator, valgrind)", "PROGRAM"),
           optopt("", "host-rustcflags", "flags to pass to rustc for host", "FLAGS"),
@@ -167,6 +168,7 @@ pub fn parse_config(args: Vec<String> ) -> Config {
         mode: matches.opt_str("mode").unwrap().parse().ok().expect("invalid mode"),
         run_ignored: matches.opt_present("ignored"),
         filter: matches.free.first().cloned(),
+        filter_exact: matches.opt_present("exact"),
         logfile: matches.opt_str("logfile").map(|s| PathBuf::from(&s)),
         runtool: matches.opt_str("runtool"),
         host_rustcflags: matches.opt_str("host-rustcflags"),
@@ -216,6 +218,7 @@ pub fn log_config(config: &Config) {
                     opt_str(&config.filter
                                    .as_ref()
                                    .map(|re| re.to_owned()))));
+    logv(c, format!("filter_exact: {}", config.filter_exact));
     logv(c, format!("runtool: {}", opt_str(&config.runtool)));
     logv(c, format!("host-rustcflags: {}",
                     opt_str(&config.host_rustcflags)));
@@ -309,6 +312,7 @@ pub fn run_tests(config: &Config) {
 pub fn test_opts(config: &Config) -> test::TestOpts {
     test::TestOpts {
         filter: config.filter.clone(),
+        filter_exact: config.filter_exact,
         run_ignored: config.run_ignored,
         quiet: config.quiet,
         logfile: config.logfile.clone(),