1use futures::channel::oneshot;
2use futures::{FutureExt, select_biased};
3use gpui::{App, Context, Global, Subscription, Task, Window};
4use std::cell::RefCell;
5use std::rc::Rc;
6use std::sync::LazyLock;
7use std::time::Duration;
8use std::{future::Future, pin::Pin, task::Poll};
9
10#[derive(Default)]
11struct FeatureFlags {
12 flags: Vec<String>,
13 staff: bool,
14}
15
16pub static ZED_DISABLE_STAFF: LazyLock<bool> = LazyLock::new(|| {
17 std::env::var("ZED_DISABLE_STAFF").map_or(false, |value| !value.is_empty() && value != "0")
18});
19
20impl FeatureFlags {
21 fn has_flag<T: FeatureFlag>(&self) -> bool {
22 if T::enabled_for_all() {
23 return true;
24 }
25
26 if self.staff && T::enabled_for_staff() {
27 return true;
28 }
29
30 self.flags.iter().any(|f| f.as_str() == T::NAME)
31 }
32}
33
34impl Global for FeatureFlags {}
35
36/// To create a feature flag, implement this trait on a trivial type and use it as
37/// a generic parameter when called [`FeatureFlagAppExt::has_flag`].
38///
39/// Feature flags are enabled for members of Zed staff by default. To disable this behavior
40/// so you can test flags being disabled, set ZED_DISABLE_STAFF=1 in your environment,
41/// which will force Zed to treat the current user as non-staff.
42pub trait FeatureFlag {
43 const NAME: &'static str;
44
45 /// Returns whether this feature flag is enabled for Zed staff.
46 fn enabled_for_staff() -> bool {
47 true
48 }
49
50 /// Returns whether this feature flag is enabled for everyone.
51 ///
52 /// This is generally done on the server, but we provide this as a way to entirely enable a feature flag client-side
53 /// without needing to remove all of the call sites.
54 fn enabled_for_all() -> bool {
55 false
56 }
57}
58
59pub struct PredictEditsRateCompletionsFeatureFlag;
60impl FeatureFlag for PredictEditsRateCompletionsFeatureFlag {
61 const NAME: &'static str = "predict-edits-rate-completions";
62}
63
64pub struct LlmClosedBetaFeatureFlag {}
65impl FeatureFlag for LlmClosedBetaFeatureFlag {
66 const NAME: &'static str = "llm-closed-beta";
67}
68
69pub struct ZedProFeatureFlag {}
70impl FeatureFlag for ZedProFeatureFlag {
71 const NAME: &'static str = "zed-pro";
72}
73
74pub struct NotebookFeatureFlag;
75
76impl FeatureFlag for NotebookFeatureFlag {
77 const NAME: &'static str = "notebooks";
78}
79
80pub struct DebuggerFeatureFlag {}
81impl FeatureFlag for DebuggerFeatureFlag {
82 const NAME: &'static str = "debugger";
83}
84
85pub struct ThreadAutoCaptureFeatureFlag {}
86impl FeatureFlag for ThreadAutoCaptureFeatureFlag {
87 const NAME: &'static str = "thread-auto-capture";
88
89 fn enabled_for_staff() -> bool {
90 false
91 }
92}
93
94pub struct JjUiFeatureFlag {}
95
96impl FeatureFlag for JjUiFeatureFlag {
97 const NAME: &'static str = "jj-ui";
98}
99
100pub trait FeatureFlagViewExt<V: 'static> {
101 fn observe_flag<T: FeatureFlag, F>(&mut self, window: &Window, callback: F) -> Subscription
102 where
103 F: Fn(bool, &mut V, &mut Window, &mut Context<V>) + Send + Sync + 'static;
104
105 fn when_flag_enabled<T: FeatureFlag>(
106 &mut self,
107 window: &mut Window,
108 callback: impl Fn(&mut V, &mut Window, &mut Context<V>) + Send + Sync + 'static,
109 );
110}
111
112impl<V> FeatureFlagViewExt<V> for Context<'_, V>
113where
114 V: 'static,
115{
116 fn observe_flag<T: FeatureFlag, F>(&mut self, window: &Window, callback: F) -> Subscription
117 where
118 F: Fn(bool, &mut V, &mut Window, &mut Context<V>) + 'static,
119 {
120 self.observe_global_in::<FeatureFlags>(window, move |v, window, cx| {
121 let feature_flags = cx.global::<FeatureFlags>();
122 callback(feature_flags.has_flag::<T>(), v, window, cx);
123 })
124 }
125
126 fn when_flag_enabled<T: FeatureFlag>(
127 &mut self,
128 window: &mut Window,
129 callback: impl Fn(&mut V, &mut Window, &mut Context<V>) + Send + Sync + 'static,
130 ) {
131 if self
132 .try_global::<FeatureFlags>()
133 .is_some_and(|f| f.has_flag::<T>())
134 {
135 self.defer_in(window, move |view, window, cx| {
136 callback(view, window, cx);
137 });
138 return;
139 }
140 let subscription = Rc::new(RefCell::new(None));
141 let inner = self.observe_global_in::<FeatureFlags>(window, {
142 let subscription = subscription.clone();
143 move |v, window, cx| {
144 let feature_flags = cx.global::<FeatureFlags>();
145 if feature_flags.has_flag::<T>() {
146 callback(v, window, cx);
147 subscription.take();
148 }
149 }
150 });
151 subscription.borrow_mut().replace(inner);
152 }
153}
154
155pub trait FeatureFlagAppExt {
156 fn wait_for_flag<T: FeatureFlag>(&mut self) -> WaitForFlag;
157
158 /// Waits for the specified feature flag to resolve, up to the given timeout.
159 fn wait_for_flag_or_timeout<T: FeatureFlag>(&mut self, timeout: Duration) -> Task<bool>;
160
161 fn update_flags(&mut self, staff: bool, flags: Vec<String>);
162 fn set_staff(&mut self, staff: bool);
163 fn has_flag<T: FeatureFlag>(&self) -> bool;
164 fn is_staff(&self) -> bool;
165
166 fn observe_flag<T: FeatureFlag, F>(&mut self, callback: F) -> Subscription
167 where
168 F: FnMut(bool, &mut App) + 'static;
169}
170
171impl FeatureFlagAppExt for App {
172 fn update_flags(&mut self, staff: bool, flags: Vec<String>) {
173 let feature_flags = self.default_global::<FeatureFlags>();
174 feature_flags.staff = staff;
175 feature_flags.flags = flags;
176 }
177
178 fn set_staff(&mut self, staff: bool) {
179 let feature_flags = self.default_global::<FeatureFlags>();
180 feature_flags.staff = staff;
181 }
182
183 fn has_flag<T: FeatureFlag>(&self) -> bool {
184 self.try_global::<FeatureFlags>()
185 .map(|flags| flags.has_flag::<T>())
186 .unwrap_or(false)
187 }
188
189 fn is_staff(&self) -> bool {
190 self.try_global::<FeatureFlags>()
191 .map(|flags| flags.staff)
192 .unwrap_or(false)
193 }
194
195 fn observe_flag<T: FeatureFlag, F>(&mut self, mut callback: F) -> Subscription
196 where
197 F: FnMut(bool, &mut App) + 'static,
198 {
199 self.observe_global::<FeatureFlags>(move |cx| {
200 let feature_flags = cx.global::<FeatureFlags>();
201 callback(feature_flags.has_flag::<T>(), cx);
202 })
203 }
204
205 fn wait_for_flag<T: FeatureFlag>(&mut self) -> WaitForFlag {
206 let (tx, rx) = oneshot::channel::<bool>();
207 let mut tx = Some(tx);
208 let subscription: Option<Subscription>;
209
210 match self.try_global::<FeatureFlags>() {
211 Some(feature_flags) => {
212 subscription = None;
213 tx.take().unwrap().send(feature_flags.has_flag::<T>()).ok();
214 }
215 None => {
216 subscription = Some(self.observe_global::<FeatureFlags>(move |cx| {
217 let feature_flags = cx.global::<FeatureFlags>();
218 if let Some(tx) = tx.take() {
219 tx.send(feature_flags.has_flag::<T>()).ok();
220 }
221 }));
222 }
223 }
224
225 WaitForFlag(rx, subscription)
226 }
227
228 fn wait_for_flag_or_timeout<T: FeatureFlag>(&mut self, timeout: Duration) -> Task<bool> {
229 let wait_for_flag = self.wait_for_flag::<T>();
230
231 self.spawn(async move |_cx| {
232 let mut wait_for_flag = wait_for_flag.fuse();
233 let mut timeout = FutureExt::fuse(smol::Timer::after(timeout));
234
235 select_biased! {
236 is_enabled = wait_for_flag => is_enabled,
237 _ = timeout => false,
238 }
239 })
240 }
241}
242
243pub struct WaitForFlag(oneshot::Receiver<bool>, Option<Subscription>);
244
245impl Future for WaitForFlag {
246 type Output = bool;
247
248 fn poll(mut self: Pin<&mut Self>, cx: &mut core::task::Context<'_>) -> Poll<Self::Output> {
249 self.0.poll_unpin(cx).map(|result| {
250 self.1.take();
251 result.unwrap_or(false)
252 })
253 }
254}