From 4620f82a13adce6c324baa6ed77dce511a586504 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Sat, 31 Dec 2022 11:52:16 -0800
Subject: [PATCH 1/2] Fix tidy unittest.

---
 src/tools/tidy/src/features/version/tests.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tools/tidy/src/features/version/tests.rs b/src/tools/tidy/src/features/version/tests.rs
index 31224fdf1ea..7701dce2df1 100644
--- a/src/tools/tidy/src/features/version/tests.rs
+++ b/src/tools/tidy/src/features/version/tests.rs
@@ -12,8 +12,8 @@ fn test_try_from_invalid_version() {
 
 #[test]
 fn test_try_from_single() {
-    assert_eq!("1.32.0".parse(), Ok(Version { parts: [1, 32, 0] }));
-    assert_eq!("1.0.0".parse(), Ok(Version { parts: [1, 0, 0] }));
+    assert_eq!("1.32.0".parse(), Ok(Version::Explicit { parts: [1, 32, 0] }));
+    assert_eq!("1.0.0".parse(), Ok(Version::Explicit { parts: [1, 0, 0] }));
 }
 
 #[test]

From 59b80f598fd983a3800d6f2ffd23f0a5a89c3f4f Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Sat, 31 Dec 2022 12:31:42 -0800
Subject: [PATCH 2/2] Run `cargo test` on tidy itself.

---
 src/bootstrap/builder.rs                      |  1 +
 src/bootstrap/test.rs                         | 34 +++++++++++++++++++
 .../host-x86_64/mingw-check-tidy/Dockerfile   |  2 +-
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 66bc0f023b6..b54bf432621 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -662,6 +662,7 @@ impl<'a> Builder<'a> {
                 crate::toolstate::ToolStateCheck,
                 test::ExpandYamlAnchors,
                 test::Tidy,
+                test::TidySelfTest,
                 test::Ui,
                 test::RunPassValgrind,
                 test::MirOpt,
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index d5bec268a45..ea906be7e3a 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1143,6 +1143,40 @@ help: to skip test's attempt to check tidiness, pass `--exclude src/tools/tidy`
     }
 }
 
+/// Runs tidy's own tests.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct TidySelfTest;
+
+impl Step for TidySelfTest {
+    type Output = ();
+    const DEFAULT: bool = true;
+    const ONLY_HOSTS: bool = true;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.alias("tidyselftest")
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(TidySelfTest);
+    }
+
+    fn run(self, builder: &Builder<'_>) {
+        let bootstrap_host = builder.config.build;
+        let compiler = builder.compiler(0, bootstrap_host);
+        let cargo = tool::prepare_tool_cargo(
+            builder,
+            compiler,
+            Mode::ToolBootstrap,
+            bootstrap_host,
+            "test",
+            "src/tools/tidy",
+            SourceType::InTree,
+            &[],
+        );
+        try_run(builder, &mut cargo.into());
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct ExpandYamlAnchors;
 
diff --git a/src/ci/docker/host-x86_64/mingw-check-tidy/Dockerfile b/src/ci/docker/host-x86_64/mingw-check-tidy/Dockerfile
index 78fee152eb9..c340294fc73 100644
--- a/src/ci/docker/host-x86_64/mingw-check-tidy/Dockerfile
+++ b/src/ci/docker/host-x86_64/mingw-check-tidy/Dockerfile
@@ -33,4 +33,4 @@ COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
 COPY host-x86_64/mingw-check/validate-error-codes.sh /scripts/
 
 ENV RUN_CHECK_WITH_PARALLEL_QUERIES 1
-ENV SCRIPT python3 ../x.py test --stage 0 src/tools/tidy
+ENV SCRIPT python3 ../x.py test --stage 0 src/tools/tidy tidyselftest