Add Loops Transparency (#631)

app/src/lib/sendLoopsEvent.ts

@@ -1,13 +1,41 @@
+// keep a simple cache that prevents the same loops event from being sent twice
+// in the same session
+const sentEvents = new Set<string>();
+
 export function sendLoopsEvent(body: { email: string; eventName: string }) {
-  if (process.env.REACT_APP_VERCEL_ENV !== "production") return;
+  if (process.env.REACT_APP_VERCEL_ENV !== "production") {
+    console.log("Not sending loops event in dev mode");
+    return;
+  }
+
+  const key = `${body.email}:${body.eventName}`;
+  if (sentEvents.has(key)) {
+    console.log(
+      `Loops event: ${body.eventName} for ${body.email} already sent`
+    );
+    return;
+  }
+  sentEvents.add(key);
+
+  console.log(`Loops event: ${body.eventName} for ${body.email} sent`);
 
   fetch("/api/loops-event", {
     method: "POST",
     headers: {
       "Content-Type": "application/json",
     },
     body: JSON.stringify(body),
-  });
+  })
+    .then((res) => {
+      if (!res.ok) {
+        console.error("Failed to send loops event", res);
+      } else {
+        console.log("Sent loops event", body);
+      }
+    })
+    .catch((err) => {
+      console.error("Failed to send loops event", err);
+    });
 }
 
 export function loopsNewSubscriber(email: string) {