Fast rerun

src/config.rs

@@ -53,6 +53,8 @@ pub struct Config {
     pub filter_files: Vec<String>,
     /// Override the number of threads to use.
     pub threads: Option<NonZeroUsize>,
+    /// Rerun tests even if they passed previously
+    pub force_rerun: bool,
 }
 
 impl Config {
@@ -94,6 +96,7 @@ impl Config {
             skip_files: Vec::new(),
             filter_files: Vec::new(),
             threads: None,
+            force_rerun: false,
         }
     }
 
@@ -120,6 +123,7 @@ impl Config {
         let Args {
             ref filters,
             quiet: _,
+            force_rerun,
             check,
             bless,
             threads,
@@ -130,6 +134,7 @@ impl Config {
 
         self.filter_files.extend_from_slice(filters);
         self.skip_files.extend_from_slice(skip);
+        self.force_rerun |= force_rerun;
 
         let bless = match (bless, check) {
             (_, true) => false,

src/config/args.rs

@@ -18,6 +18,10 @@ pub struct Args {
     /// output.
     pub check: bool,
 
+    /// Rerun all tests, even if their test files are unchanged and they passed
+    /// in a previous run.
+    pub force_rerun: bool,
+
     /// Whether to overwrite `.stderr` files on mismtach with the actual
     /// output.
     pub bless: bool,
@@ -48,6 +52,8 @@ impl Args {
                 self.check = true;
             } else if arg == "--bless" {
                 self.bless = true;
+            } else if arg == "--force-rerun" {
+                self.force_rerun = true;
             } else if let Some(skip) = parse_value("--skip", &arg, &mut iter)? {
                 self.skip.push(skip.into_owned());
             } else if arg == "--help" {

src/lib.rs

@@ -148,14 +148,35 @@ pub fn default_file_filter(path: &Path, config: &Config) -> bool {
 ///
 /// To only include rust files see [`default_file_filter`].
 pub fn default_any_file_filter(path: &Path, config: &Config) -> bool {
-    let path = path.display().to_string();
-    let contains_path = |files: &[String]| files.iter().any(|f| path.contains(f));
+    let path_str = path.display().to_string();
+    let contains_path = |files: &[String]| files.iter().any(|f| path_str.contains(f));
 
     if contains_path(&config.skip_files) {
         return false;
     }
 
-    config.filter_files.is_empty() || contains_path(&config.filter_files)
+    if !config.filter_files.is_empty() && !contains_path(&config.filter_files) {
+        return false;
+    }
+    config.force_rerun || modified_since_last_successful_run(path, config)
+}
+
+/// Returns `true` if the file was modified since the last time it was tested and passed successfully.
+pub fn modified_since_last_successful_run(path: &Path, config: &Config) -> bool {
+    macro_rules! modified {
+        ($path:expr) => {
+            if let Ok(time) = std::fs::metadata(&$path).and_then(|m| m.modified()) {
+                time
+            } else {
+                // If we can't get a time, assume the file has been modified.
+                return true;
+            }
+        };
+    }
+    let file_modified = modified!(path);
+    let test_suite = modified!(std::env::current_exe().unwrap());
+    let check_file = modified!(config.out_dir.join(path.with_extension("timestamp")));
+    (check_file < test_suite) || (check_file < file_modified)
 }
 
 /// The default per-file config used by `run_tests`.
@@ -271,6 +292,10 @@ pub fn run_tests_generic(
                         todo.push_back((entry, config));
                     }
                 } else if file_filter(&path, config) {
+                    // If we start a test, remove the marker that it was cached.
+                    let check_file = config.out_dir.join(path.with_extension("timestamp"));
+                    // The file may not exist, in this case we don't need to do anything.
+                    let _ = std::fs::remove_file(check_file);
                     let status = status_emitter.register_test(path);
                     // Forward .rs files to the test workers.
                     submit.send((status, config)).unwrap();
@@ -636,6 +661,13 @@ impl dyn TestStatus {
         run_rustfix(
             &stderr, &stdout, path, comments, revision, config, *mode, extra_args,
         )?;
+
+        // Make sure the `default_file_filter` recognizes that the test has already been run successfully
+        // and avoid running it again.
+        let check_file = config.out_dir.join(path.with_extension("timestamp"));
+        std::fs::create_dir_all(check_file.parent().unwrap()).unwrap();
+        std::fs::File::create(check_file).unwrap();
+
         Ok(TestOk::Ok)
     }
 

tests/integrations/basic-bin/tests/ui_tests.rs

@@ -9,6 +9,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
         } else {
             OutputConflictHandling::Error("cargo test".to_string())
         },
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
     config.stderr_filter("in ([0-9]m )?[0-9\\.]+s", "");

tests/integrations/basic-fail-mode/tests/ui_tests.rs

@@ -13,6 +13,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
         } else {
             OutputConflictHandling::Error("cargo test".to_string())
         },
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
     config.stderr_filter("in ([0-9]m )?[0-9\\.]+s", "");

tests/integrations/basic-fail/Cargo.stderr

@@ -9,7 +9,7 @@ Caused by:
 thread 'main' panicked at 'invalid mode/result combo: yolo: Err(tests failed
 
 Location:
-    $DIR/src/lib.rs:LL:CC)', tests/ui_tests_bless.rs:52:18
+    $DIR/src/lib.rs:LL:CC)', tests/ui_tests_bless.rs:53:18
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 error: test failed, to rerun pass `--test ui_tests_bless`
 Error: failed to parse rustc version info: invalid_foobarlaksdfalsdfj

tests/integrations/basic-fail/tests/ui_tests.rs

@@ -8,7 +8,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
         output_conflict_handling: OutputConflictHandling::Error(
             "DO NOT BLESS. These are meant to fail".into(),
         ),
-
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
 

tests/integrations/basic-fail/tests/ui_tests_bless.rs

@@ -26,6 +26,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
                 OutputConflictHandling::Error("cargo test".to_string())
             },
             mode,
+            force_rerun: true,
             ..Config::rustc(root_dir)
         };
 

tests/integrations/basic-fail/tests/ui_tests_invalid_program.rs

@@ -7,6 +7,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
         output_conflict_handling: OutputConflictHandling::Error(
             "DO NOT BLESS. These are meant to fail".into(),
         ),
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
 

tests/integrations/basic-fail/tests/ui_tests_invalid_program2.rs

@@ -8,6 +8,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
             "DO NOT BLESS. These are meant to fail".into(),
         ),
         host: Some("foo".into()),
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
 

tests/integrations/basic/tests/ui_tests.rs

@@ -9,6 +9,7 @@ fn main() -> ui_test::color_eyre::Result<()> {
         } else {
             OutputConflictHandling::Error("cargo test".to_string())
         },
+        force_rerun: true,
         ..Config::rustc("tests/actual_tests")
     };
     config.stderr_filter("in ([0-9]m )?[0-9\\.]+s", "");