4 files changed, 168 insertions, 0 deletions
diff --git a/third_party/rust/tracing-core/tests/common/mod.rs b/third_party/rust/tracing-core/tests/common/mod.rs
new file mode 100644
index 0000000000..3420f0b899
--- /dev/null
+++ b/third_party/rust/tracing-core/tests/common/mod.rs
@@ -0,0 +1,30 @@
+use tracing_core::{metadata::Metadata, span, subscriber::Subscriber, Event};
+
+pub struct TestSubscriberA;
+impl Subscriber for TestSubscriberA {
+    fn enabled(&self, _: &Metadata<'_>) -> bool {
+        true
+    }
+    fn new_span(&self, _: &span::Attributes<'_>) -> span::Id {
+        span::Id::from_u64(1)
+    }
+    fn record(&self, _: &span::Id, _: &span::Record<'_>) {}
+    fn record_follows_from(&self, _: &span::Id, _: &span::Id) {}
+    fn event(&self, _: &Event<'_>) {}
+    fn enter(&self, _: &span::Id) {}
+    fn exit(&self, _: &span::Id) {}
+}
+pub struct TestSubscriberB;
+impl Subscriber for TestSubscriberB {
+    fn enabled(&self, _: &Metadata<'_>) -> bool {
+        true
+    }
+    fn new_span(&self, _: &span::Attributes<'_>) -> span::Id {
+        span::Id::from_u64(1)
+    }
+    fn record(&self, _: &span::Id, _: &span::Record<'_>) {}
+    fn record_follows_from(&self, _: &span::Id, _: &span::Id) {}
+    fn event(&self, _: &Event<'_>) {}
+    fn enter(&self, _: &span::Id) {}
+    fn exit(&self, _: &span::Id) {}
+}
diff --git a/third_party/rust/tracing-core/tests/dispatch.rs b/third_party/rust/tracing-core/tests/dispatch.rs
new file mode 100644
index 0000000000..3820692a86
--- /dev/null
+++ b/third_party/rust/tracing-core/tests/dispatch.rs
@@ -0,0 +1,56 @@
+#![cfg(feature = "std")]
+mod common;
+
+use common::*;
+use tracing_core::dispatcher::*;
+
+#[test]
+fn set_default_dispatch() {
+    set_global_default(Dispatch::new(TestSubscriberA)).expect("global dispatch set failed");
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "global dispatch get failed"
+        )
+    });
+
+    let guard = set_default(&Dispatch::new(TestSubscriberB));
+    get_default(|current| assert!(current.is::<TestSubscriberB>(), "set_default get failed"));
+
+    // Drop the guard, setting the dispatch back to the global dispatch
+    drop(guard);
+
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "global dispatch get failed"
+        )
+    });
+}
+
+#[test]
+fn nested_set_default() {
+    let _guard = set_default(&Dispatch::new(TestSubscriberA));
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "set_default for outer subscriber failed"
+        )
+    });
+
+    let inner_guard = set_default(&Dispatch::new(TestSubscriberB));
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberB>(),
+            "set_default inner subscriber failed"
+        )
+    });
+
+    drop(inner_guard);
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "set_default outer subscriber failed"
+        )
+    });
+}
diff --git a/third_party/rust/tracing-core/tests/global_dispatch.rs b/third_party/rust/tracing-core/tests/global_dispatch.rs
new file mode 100644
index 0000000000..d430ac6182
--- /dev/null
+++ b/third_party/rust/tracing-core/tests/global_dispatch.rs
@@ -0,0 +1,34 @@
+mod common;
+
+use common::*;
+use tracing_core::dispatcher::*;
+#[test]
+fn global_dispatch() {
+    set_global_default(Dispatch::new(TestSubscriberA)).expect("global dispatch set failed");
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "global dispatch get failed"
+        )
+    });
+
+    #[cfg(feature = "std")]
+    with_default(&Dispatch::new(TestSubscriberB), || {
+        get_default(|current| {
+            assert!(
+                current.is::<TestSubscriberB>(),
+                "thread-local override of global dispatch failed"
+            )
+        });
+    });
+
+    get_default(|current| {
+        assert!(
+            current.is::<TestSubscriberA>(),
+            "reset to global override failed"
+        )
+    });
+
+    set_global_default(Dispatch::new(TestSubscriberA))
+        .expect_err("double global dispatch set succeeded");
+}
diff --git a/third_party/rust/tracing-core/tests/macros.rs b/third_party/rust/tracing-core/tests/macros.rs
new file mode 100644
index 0000000000..ee9007eeeb
--- /dev/null
+++ b/third_party/rust/tracing-core/tests/macros.rs
@@ -0,0 +1,48 @@
+use tracing_core::{
+    callsite::Callsite,
+    metadata,
+    metadata::{Kind, Level, Metadata},
+    subscriber::Interest,
+};
+
+#[test]
+fn metadata_macro_api() {
+    // This test should catch any inadvertent breaking changes
+    // caused by changes to the macro.
+    struct TestCallsite;
+
+    impl Callsite for TestCallsite {
+        fn set_interest(&self, _: Interest) {
+            unimplemented!("test")
+        }
+        fn metadata(&self) -> &Metadata<'_> {
+            unimplemented!("test")
+        }
+    }
+
+    static CALLSITE: TestCallsite = TestCallsite;
+    let _metadata = metadata! {
+        name: "test_metadata",
+        target: "test_target",
+        level: Level::DEBUG,
+        fields: &["foo", "bar", "baz"],
+        callsite: &CALLSITE,
+        kind: Kind::SPAN,
+    };
+    let _metadata = metadata! {
+        name: "test_metadata",
+        target: "test_target",
+        level: Level::TRACE,
+        fields: &[],
+        callsite: &CALLSITE,
+        kind: Kind::EVENT,
+    };
+    let _metadata = metadata! {
+        name: "test_metadata",
+        target: "test_target",
+        level: Level::INFO,
+        fields: &[],
+        callsite: &CALLSITE,
+        kind: Kind::EVENT
+    };
+}