Add telemetry::event! (#22146)

CC @JosephTLyons

Release Notes:

- N/A

crates/telemetry/src/telemetry.rs

@@ -0,0 +1,57 @@
+//! See [Telemetry in Zed](https://zed.dev/docs/telemetry) for additional information.
+use futures::channel::mpsc;
+pub use serde_json;
+use std::sync::OnceLock;
+pub use telemetry_events::FlexibleEvent as Event;
+
+/// Macro to create telemetry events and send them to the telemetry queue.
+///
+/// By convention, the name should be "Noun Verbed", e.g. "Keymap Changed"
+/// or "Project Diagnostics Opened".
+///
+/// The properties can be any value that implements serde::Serialize.
+///
+/// ```
+/// telemetry::event!("Keymap Changed", version = "1.0.0");
+/// telemetry::event!("Documentation Viewed", url, source = "Extension Upsell");
+/// ```
+#[macro_export]
+macro_rules! event {
+    ($name:expr, $($key:ident $(= $value:expr)?),+ $(,)?) => {{
+        let event = $crate::Event {
+            event_type: $name.to_string(),
+            event_properties: std::collections::HashMap::from([
+                $(
+                    (stringify!($key).to_string(),
+                        $crate::serde_json::value::to_value(&$crate::serialize_property!($key $(= $value)?))
+                            .unwrap_or_else(|_| $crate::serde_json::to_value(&()).unwrap())
+                    ),
+                )+
+            ]),
+        };
+        $crate::send_event(event);
+    }};
+}
+
+#[macro_export]
+macro_rules! serialize_property {
+    ($key:ident) => {
+        $key
+    };
+    ($key:ident = $value:expr) => {
+        $value
+    };
+}
+
+pub fn send_event(event: Event) {
+    if let Some(queue) = TELEMETRY_QUEUE.get() {
+        queue.unbounded_send(event).ok();
+        return;
+    }
+}
+
+pub fn init(tx: mpsc::UnboundedSender<Event>) {
+    TELEMETRY_QUEUE.set(tx).ok();
+}
+
+static TELEMETRY_QUEUE: OnceLock<mpsc::UnboundedSender<Event>> = OnceLock::new();