diff --git a/fish-rust/src/tests/debounce.rs b/fish-rust/src/tests/debounce.rs
new file mode 100644
index 000000000..ef03971ba
--- /dev/null
+++ b/fish-rust/src/tests/debounce.rs
@@ -0,0 +1,123 @@
+use std::sync::{
+    atomic::{AtomicU32, Ordering},
+    Arc, Condvar, Mutex,
+};
+use std::time::Duration;
+
+use crate::ffi_tests::add_test;
+use crate::global_safety::RelaxedAtomicBool;
+use crate::threads::{iothread_drain_all, iothread_service_main, Debounce};
+use crate::wchar::prelude::*;
+
+add_test!("test_debounce", || {
+    // Run 8 functions using a condition variable.
+    // Only the first and last should run.
+    let db = Debounce::new(Duration::from_secs(0));
+    const count: usize = 8;
+
+    struct Context {
+        handler_ran: [RelaxedAtomicBool; count],
+        completion_ran: [RelaxedAtomicBool; count],
+        ready_to_go: Mutex<bool>,
+        cv: Condvar,
+    }
+
+    let ctx = Arc::new(Context {
+        handler_ran: std::array::from_fn(|_i| RelaxedAtomicBool::new(false)),
+        completion_ran: std::array::from_fn(|_i| RelaxedAtomicBool::new(false)),
+        ready_to_go: Mutex::new(false),
+        cv: Condvar::new(),
+    });
+
+    // "Enqueue" all functions. Each one waits until ready_to_go.
+    for idx in 0..count {
+        assert!(!ctx.handler_ran[idx].load());
+        let performer = {
+            let ctx = ctx.clone();
+            move || {
+                let guard = ctx.ready_to_go.lock().unwrap();
+                let _guard = ctx.cv.wait_while(guard, |ready| !*ready).unwrap();
+                ctx.handler_ran[idx].store(true);
+                idx
+            }
+        };
+        let completer = {
+            let ctx = ctx.clone();
+            move |idx: usize| {
+                ctx.completion_ran[idx].store(true);
+            }
+        };
+        db.perform_with_completion(performer, completer);
+    }
+
+    // We're ready to go.
+    *ctx.ready_to_go.lock().unwrap() = true;
+    ctx.cv.notify_all();
+
+    // Wait until the last completion is done.
+    while !ctx.completion_ran.last().unwrap().load() {
+        iothread_service_main();
+    }
+    unsafe { iothread_drain_all() };
+
+    // Each perform() call may displace an existing queued operation.
+    // Each operation waits until all are queued.
+    // Therefore we expect the last perform() to have run, and at most one more.
+    assert!(ctx.handler_ran.last().unwrap().load());
+    assert!(ctx.completion_ran.last().unwrap().load());
+
+    let mut total_ran = 0;
+    for idx in 0..count {
+        if ctx.handler_ran[idx].load() {
+            total_ran += 1;
+        }
+        assert_eq!(ctx.handler_ran[idx].load(), ctx.completion_ran[idx].load());
+    }
+    assert!(total_ran <= 2);
+});
+
+add_test!("test_debounce_timeout", || {
+    // Verify that debounce doesn't wait forever.
+    // Use a shared_ptr so we don't have to join our threads.
+    let timeout = Duration::from_millis(500);
+
+    struct Data {
+        db: Debounce,
+        exit_ok: Mutex<bool>,
+        cv: Condvar,
+        running: AtomicU32,
+    }
+
+    let data = Arc::new(Data {
+        db: Debounce::new(timeout),
+        exit_ok: Mutex::new(false),
+        cv: Condvar::new(),
+        running: AtomicU32::new(0),
+    });
+
+    // Our background handler. Note this just blocks until exit_ok is set.
+    let handler = {
+        let data = data.clone();
+        move || {
+            data.running.fetch_add(1, Ordering::Relaxed);
+            let guard = data.exit_ok.lock().unwrap();
+            let _guard = data.cv.wait_while(guard, |exit_ok| !*exit_ok);
+        }
+    };
+
+    // Spawn the handler twice. This should not modify the thread token.
+    let token1 = data.db.perform(handler.clone());
+    let token2 = data.db.perform(handler.clone());
+    assert_eq!(token1, token2);
+
+    // Wait 75 msec, then enqueue something else; this should spawn a new thread.
+    std::thread::sleep(timeout + timeout / 2);
+    assert!(data.running.load(Ordering::Relaxed) == 1);
+    let token3 = data.db.perform(handler.clone());
+    assert!(token3 > token2);
+
+    // Release all the threads.
+    let mut exit_ok = data.exit_ok.lock().unwrap();
+    *exit_ok = true;
+    data.cv.notify_all();
+});
diff --git a/fish-rust/src/tests/mod.rs b/fish-rust/src/tests/mod.rs
index dc33f2df5..69ad761b1 100644
--- a/fish-rust/src/tests/mod.rs
+++ b/fish-rust/src/tests/mod.rs
@@ -3,6 +3,7 @@ use crate::wchar::prelude::*;
 #[cfg(test)]
 mod common;
 mod complete;
+mod debounce;
 #[cfg(test)]
 mod editable_line;
 mod env;
diff --git a/src/fish_tests.cpp b/src/fish_tests.cpp
index 6a8e35d7d..91ea37725 100644
--- a/src/fish_tests.cpp
+++ b/src/fish_tests.cpp
@@ -524,102 +524,6 @@ static void test_pthread() {
     do_test(val == 5);
 }
 
-// todo!("port this");
-static void test_debounce() {
-    say(L"Testing debounce");
-    // Run 8 functions using a condition variable.
-    // Only the first and last should run.
-    auto db = new_debounce_t(0);
-    constexpr size_t count = 8;
-    std::array<bool, count> handler_ran = {};
-    std::array<bool, count> completion_ran = {};
-
-    bool ready_to_go = false;
-    std::mutex m;
-    std::condition_variable cv;
-
-    // "Enqueue" all functions. Each one waits until ready_to_go.
-    for (size_t idx = 0; idx < count; idx++) {
-        do_test(handler_ran[idx] == false);
-        std::function<size_t()> performer = [&, idx] {
-            std::unique_lock<std::mutex> lock(m);
-            cv.wait(lock, [&] { return ready_to_go; });
-            handler_ran[idx] = true;
-            return idx;
-        };
-        std::function<void(size_t)> completer = [&](size_t idx) { completion_ran[idx] = true; };
-        debounce_perform_with_completion(*db, std::move(performer), std::move(completer));
-    }
-
-    // We're ready to go.
-    {
-        std::unique_lock<std::mutex> lock(m);
-        ready_to_go = true;
-    }
-    cv.notify_all();
-
-    // Wait until the last completion is done.
-    while (!completion_ran.back()) {
-        iothread_service_main();
-    }
-    iothread_drain_all();
-
-    // Each perform() call may displace an existing queued operation.
-    // Each operation waits until all are queued.
-    // Therefore we expect the last perform() to have run, and at most one more.
-
-    do_test(handler_ran.back());
-    do_test(completion_ran.back());
-
-    size_t total_ran = 0;
-    for (size_t idx = 0; idx < count; idx++) {
-        total_ran += (handler_ran[idx] ? 1 : 0);
-        do_test(handler_ran[idx] == completion_ran[idx]);
-    }
-    do_test(total_ran <= 2);
-}
-
-// todo!("port this");
-static void test_debounce_timeout() {
-    using namespace std::chrono;
-    say(L"Testing debounce timeout");
-
-    // Verify that debounce doesn't wait forever.
-    // Use a shared_ptr so we don't have to join our threads.
-    const long timeout_ms = 500;
-    struct data_t {
-        rust::box<debounce_t> db = new_debounce_t(timeout_ms);
-        bool exit_ok = false;
-        std::mutex m;
-        std::condition_variable cv;
-        relaxed_atomic_t<uint32_t> running{0};
-    };
-    auto data = std::make_shared<data_t>();
-
-    // Our background handler. Note this just blocks until exit_ok is set.
-    std::function<void()> handler = [data] {
-        data->running++;
-        std::unique_lock<std::mutex> lock(data->m);
-        data->cv.wait(lock, [&] { return data->exit_ok; });
-    };
-
-    // Spawn the handler twice. This should not modify the thread token.
-    uint64_t token1 = debounce_perform(*data->db, handler);
-    uint64_t token2 = debounce_perform(*data->db, handler);
-    do_test(token1 == token2);
-
-    // Wait 75 msec, then enqueue something else; this should spawn a new thread.
-    std::this_thread::sleep_for(std::chrono::milliseconds(timeout_ms + timeout_ms / 2));
-    do_test(data->running == 1);
-    uint64_t token3 = debounce_perform(*data->db, handler);
-    do_test(token3 > token2);
-
-    // Release all the threads.
-    std::unique_lock<std::mutex> lock(data->m);
-    data->exit_ok = true;
-    data->cv.notify_all();
-}
-
 static parser_test_error_bits_t detect_argument_errors(const wcstring &src) {
     using namespace ast;
     auto ast = ast_parse_argument_list(src, parse_flag_none);
@@ -2271,8 +2175,6 @@ static const test_t s_tests[]{
     {TEST_GROUP("convert_nulls"), test_convert_nulls},
     {TEST_GROUP("iothread"), test_iothread},
     {TEST_GROUP("pthread"), test_pthread},
-    {TEST_GROUP("debounce"), test_debounce},
-    {TEST_GROUP("debounce"), test_debounce_timeout},
     {TEST_GROUP("parser"), test_parser},
     {TEST_GROUP("lru"), test_lru},
     {TEST_GROUP("wcstod"), test_wcstod},