From: Danny Milosavljevic <dannym@friendly-machines.com>
Date: Fri, 6 Mar 2026 21:22:41 +0000
Subject: [PATCH] db: Scope default test databases to the current test
License: expat

In test builds, the default database statics use fixed names such as
`DB` and `KEY_VALUE_STORE`. That makes unrelated tests in the same test
binary share the same named in-memory databases, which leaks state
across tests and makes failures depend on execution order and
concurrency.

A first attempt at isolating those statics by thread is not sufficient:
one test can legitimately use multiple threads, and splitting the test's
workspace state across separate databases breaks parent-child foreign key
relationships.

Fix this by scoping the default test databases by the current test name
instead. The `gpui::test` harness now installs the current test name on
the executing thread, the test dispatcher propagates that scope to its
realtime worker threads, and the default test statics resolve one shared
database wrapper per test scope rather than per thread.

That keeps sharing within a single test where it is intentional, while
stopping hidden cross-test state leakage.

diff --git a/crates/db/src/db.rs b/crates/db/src/db.rs
index 36f0365af9..3ff8499c1d 100644
--- a/crates/db/src/db.rs
+++ b/crates/db/src/db.rs
@@ -19,6 +19,12 @@ use std::future::Future;
 use std::path::Path;
 use std::sync::atomic::AtomicBool;
 use std::sync::{LazyLock, atomic::Ordering};
+#[cfg(any(test, feature = "test-support"))]
+use std::collections::HashMap;
+#[cfg(any(test, feature = "test-support"))]
+use std::sync::Mutex;
+#[cfg(any(test, feature = "test-support"))]
+use std::{borrow::Cow, ops::Deref};
 use util::{ResultExt, maybe};
 use zed_env_vars::ZED_STATELESS;
 
@@ -97,7 +103,8 @@ async fn open_fallback_db<M: Migrator>() -> ThreadSafeConnection {
 pub async fn open_test_db<M: Migrator>(db_name: &str) -> ThreadSafeConnection {
     use sqlez::thread_safe_connection::locking_queue;
 
-    ThreadSafeConnection::builder::<M>(db_name, false)
+    let db_name = scoped_test_db_name(db_name);
+    ThreadSafeConnection::builder::<M>(&db_name, false)
         .with_db_initialization_query(DB_INITIALIZE_QUERY)
         .with_connection_initialize_query(CONNECTION_INITIALIZE_QUERY)
         // Serialize queued writes via a mutex and run them synchronously
@@ -107,6 +114,69 @@ pub async fn open_test_db<M: Migrator>(db_name: &str) -> ThreadSafeConnection {
         .unwrap()
 }
 
+#[cfg(any(test, feature = "test-support"))]
+fn scoped_test_db_name(db_name: &str) -> Cow<'_, str> {
+    let Some(test_name) = current_test_scope_name() else {
+        return Cow::Borrowed(db_name);
+    };
+
+    let mut scoped_name = String::with_capacity(db_name.len() + test_name.len() + 2);
+    scoped_name.push_str(db_name);
+    scoped_name.push('@');
+    for ch in test_name.chars() {
+        if ch.is_ascii_alphanumeric() || matches!(ch, '-' | '_' | '.') {
+            scoped_name.push(ch);
+        } else {
+            scoped_name.push('_');
+        }
+    }
+
+    Cow::Owned(scoped_name)
+}
+
+#[cfg(any(test, feature = "test-support"))]
+fn current_test_scope_name() -> Option<String> {
+    if let Some(test_name) = gpui::current_test_name() {
+        return Some(test_name.to_string());
+    }
+
+    let current_thread = std::thread::current();
+    if let Some(test_name) = current_thread.name() {
+        return Some(test_name.to_string());
+    }
+
+    Some(format!("thread_{:?}", current_thread.id()))
+}
+
+#[cfg(any(test, feature = "test-support"))]
+pub struct TestScopedStatic<T: Send + Sync + 'static> {
+    initializer: fn() -> T,
+    values: Mutex<HashMap<String, &'static T>>,
+}
+
+#[cfg(any(test, feature = "test-support"))]
+impl<T: Send + Sync + 'static> TestScopedStatic<T> {
+    pub fn new(initializer: fn() -> T) -> Self {
+        Self {
+            initializer,
+            values: Mutex::new(HashMap::new()),
+        }
+    }
+}
+
+#[cfg(any(test, feature = "test-support"))]
+impl<T: Send + Sync + 'static> Deref for TestScopedStatic<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        let scope_name = current_test_scope_name().unwrap_or_else(|| "default".to_string());
+        let mut values = self.values.lock().unwrap();
+        *values
+            .entry(scope_name)
+            .or_insert_with(|| Box::leak(Box::new((self.initializer)())))
+    }
+}
+
 /// Implements a basic DB wrapper for a given domain
 ///
 /// Arguments:
@@ -126,16 +196,23 @@ macro_rules! static_connection {
 
         impl $t {
             #[cfg(any(test, feature = "test-support"))]
-            pub async fn open_test_db(name: &'static str) -> Self {
+            pub async fn open_test_db(name: &str) -> Self {
                 $t($crate::open_test_db::<$t>(name).await)
             }
         }
 
         #[cfg(any(test, feature = "test-support"))]
-        pub static $id: std::sync::LazyLock<$t> = std::sync::LazyLock::new(|| {
-            #[allow(unused_parens)]
-            $t($crate::smol::block_on($crate::open_test_db::<($($d,)* $t)>(stringify!($id))))
-        });
+        pub static $id: std::sync::LazyLock<$crate::TestScopedStatic<$t>> =
+            std::sync::LazyLock::new(|| {
+                fn initializer() -> $t {
+                    #[allow(unused_parens)]
+                    $t($crate::smol::block_on(
+                        $crate::open_test_db::<($($d,)* $t)>(stringify!($id))
+                    ))
+                }
+
+                $crate::TestScopedStatic::new(initializer)
+            });
 
         #[cfg(not(any(test, feature = "test-support")))]
         pub static $id: std::sync::LazyLock<$t> = std::sync::LazyLock::new(|| {
@@ -161,9 +238,10 @@ where
 
 #[cfg(test)]
 mod tests {
+    use anyhow::Result;
     use std::thread;
 
-    use sqlez::domain::Domain;
+    use sqlez::{domain::Domain, thread_safe_connection::ThreadSafeConnection};
     use sqlez_macros::sql;
 
     use crate::open_db;
@@ -295,4 +373,64 @@ mod tests {
             assert!(guard.join().is_ok());
         }
     }
+
+    pub struct ScopedStaticDb(ThreadSafeConnection);
+
+    impl Domain for ScopedStaticDb {
+        const NAME: &str = "test_scoped_static_db";
+        const MIGRATIONS: &[&str] = &[sql!(
+            CREATE TABLE IF NOT EXISTS scoped_values(
+                value INTEGER NOT NULL
+            ) STRICT;
+        )];
+    }
+
+    crate::static_connection!(SCOPED_STATIC_DB, ScopedStaticDb, []);
+
+    impl ScopedStaticDb {
+        fn replace_value(&self, value: i64) -> Result<()> {
+            smol::block_on(self.write(move |connection| {
+                connection.exec("DELETE FROM scoped_values")?()?;
+                connection
+                    .exec_bound("INSERT INTO scoped_values(value) VALUES (?)")
+                    ?(value)?;
+                anyhow::Ok(())
+            }))
+        }
+
+        fn read_value(&self) -> Result<Option<i64>> {
+            self.select_row::<i64>("SELECT value FROM scoped_values").unwrap()()
+        }
+    }
+
+    #[test]
+    fn static_test_connections_are_scoped_by_test_name() {
+        gpui::with_test_name(Some("static_test_connections_are_scoped_by_test_name_a"), || {
+            assert_eq!(SCOPED_STATIC_DB.read_value().unwrap(), None);
+            SCOPED_STATIC_DB.replace_value(7).unwrap();
+            assert_eq!(SCOPED_STATIC_DB.read_value().unwrap(), Some(7));
+        });
+
+        gpui::with_test_name(Some("static_test_connections_are_scoped_by_test_name_b"), || {
+            assert_eq!(SCOPED_STATIC_DB.read_value().unwrap(), None);
+            SCOPED_STATIC_DB.replace_value(11).unwrap();
+            assert_eq!(SCOPED_STATIC_DB.read_value().unwrap(), Some(11));
+        });
+    }
+
+    #[test]
+    fn static_test_connections_share_state_across_threads_with_same_test_name() {
+        gpui::with_test_name(
+            Some("static_test_connections_share_state_across_threads_with_same_test_name"),
+            || {
+                SCOPED_STATIC_DB.replace_value(13).unwrap();
+
+                let test_name = gpui::current_test_name();
+                let thread = std::thread::spawn(move || {
+                    gpui::with_test_name(test_name, || SCOPED_STATIC_DB.read_value().unwrap())
+                });
+                assert_eq!(thread.join().unwrap(), Some(13));
+            },
+        );
+    }
 }
diff --git a/crates/gpui/src/platform/test/dispatcher.rs b/crates/gpui/src/platform/test/dispatcher.rs
index fc3f7f253a..0d98b082ca 100644
--- a/crates/gpui/src/platform/test/dispatcher.rs
+++ b/crates/gpui/src/platform/test/dispatcher.rs
@@ -136,8 +136,9 @@ impl PlatformDispatcher for TestDispatcher {
     }
 
     fn spawn_realtime(&self, f: Box<dyn FnOnce() + Send>) {
+        let test_name = crate::current_test_name();
         std::thread::spawn(move || {
-            f();
+            crate::with_test_name(test_name, f);
         });
     }
 }
diff --git a/crates/gpui/src/test.rs b/crates/gpui/src/test.rs
index 9f8fd8b198..469affdc1c 100644
--- a/crates/gpui/src/test.rs
+++ b/crates/gpui/src/test.rs
@@ -29,11 +29,44 @@ use crate::{Entity, Subscription, TestAppContext, TestDispatcher};
 use futures::StreamExt as _;
 use smol::channel;
 use std::{
+    cell::Cell,
     env,
     panic::{self, RefUnwindSafe},
     pin::Pin,
 };
 
+thread_local! {
+    static CURRENT_TEST_NAME: Cell<Option<&'static str>> = const { Cell::new(None) };
+}
+
+/// Returns the test name currently associated with this thread, if any.
+pub fn current_test_name() -> Option<&'static str> {
+    CURRENT_TEST_NAME.with(Cell::get)
+}
+
+/// Runs the closure with the given test name installed for the current thread.
+pub fn with_test_name<R>(name: Option<&'static str>, f: impl FnOnce() -> R) -> R {
+    CURRENT_TEST_NAME.with(|current_name| {
+        struct RestoreTestName<'a> {
+            current_name: &'a Cell<Option<&'static str>>,
+            previous_name: Option<&'static str>,
+        }
+
+        impl Drop for RestoreTestName<'_> {
+            fn drop(&mut self) {
+                self.current_name.set(self.previous_name);
+            }
+        }
+
+        let previous_name = current_name.replace(name);
+        let _restore = RestoreTestName {
+            current_name,
+            previous_name,
+        };
+        f()
+    })
+}
+
 /// Run the given test function with the configured parameters.
 /// This is intended for use with the `gpui::test` macro
 /// and generally should not be used directly.
diff --git a/crates/gpui_macros/src/test.rs b/crates/gpui_macros/src/test.rs
index 490ea07fee..3abcaad3ae 100644
--- a/crates/gpui_macros/src/test.rs
+++ b/crates/gpui_macros/src/test.rs
@@ -191,10 +191,12 @@ fn generate_test_function(
                     &[#seeds],
                     #max_retries,
                     &mut |dispatcher, _seed| {
-                        let foreground_executor = gpui::ForegroundExecutor::new(std::sync::Arc::new(dispatcher.clone()));
-                        #cx_vars
-                        foreground_executor.block_test(#inner_fn_name(#inner_fn_args));
-                        #cx_teardowns
+                        gpui::with_test_name(Some(stringify!(#outer_fn_name)), || {
+                            let foreground_executor = gpui::ForegroundExecutor::new(std::sync::Arc::new(dispatcher.clone()));
+                            #cx_vars
+                            foreground_executor.block_test(#inner_fn_name(#inner_fn_args));
+                            #cx_teardowns
+                        })
                     },
                     #on_failure_fn_name
                 );
@@ -274,9 +276,11 @@ fn generate_test_function(
                     &[#seeds],
                     #max_retries,
                     &mut |dispatcher, _seed| {
-                        #cx_vars
-                        #inner_fn_name(#inner_fn_args);
-                        #cx_teardowns
+                        gpui::with_test_name(Some(stringify!(#outer_fn_name)), || {
+                            #cx_vars
+                            #inner_fn_name(#inner_fn_args);
+                            #cx_teardowns
+                        })
                     },
                     #on_failure_fn_name,
                 );
