feat(tracing): Restrict sentry_capture_event so it only sends non-t…

…ransaction events (#629)

Prevent the public API from being used to send transaction events
as another transaction-specific function is meant to be used to 
accomplish this.

include/sentry.h

@@ -1103,7 +1103,8 @@ SENTRY_API void sentry_user_consent_reset(void);
 SENTRY_API sentry_user_consent_t sentry_user_consent_get(void);
 
 /**
- * Sends a sentry event.
+ * Sends a sentry event. Returns a nil UUID if the event being passed in is a
+ * transaction; `sentry_transaction_finish` should be used to send transactions.
  */
 SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
 

src/sentry_core.c

@@ -362,14 +362,28 @@ sentry__event_is_transaction(sentry_value_t event)
 
 sentry_uuid_t
 sentry_capture_event(sentry_value_t event)
+{
+    if (sentry__event_is_transaction(event)) {
+        return sentry_uuid_nil();
+    } else {
+        return sentry__capture_event(event);
+    }
+}
+
+sentry_uuid_t
+sentry__capture_event(sentry_value_t event)
 {
     sentry_uuid_t event_id;
     sentry_envelope_t *envelope = NULL;
 
     bool was_captured = false;
     SENTRY_WITH_OPTIONS (options) {
         was_captured = true;
-        envelope = sentry__prepare_event(options, event, &event_id);
+        if (sentry__event_is_transaction(event)) {
+            return sentry_uuid_nil();
+        } else {
+            envelope = sentry__prepare_event(options, event, &event_id);
+        }
         if (envelope) {
             if (options->session) {
                 SENTRY_WITH_OPTIONS_MUT (mut_options) {

src/sentry_core.h

@@ -51,6 +51,11 @@ bool sentry__event_is_transaction(sentry_value_t event);
 sentry_envelope_t *sentry__prepare_event(const sentry_options_t *options,
     sentry_value_t event, sentry_uuid_t *event_id);
 
+/**
+ * Sends a sentry event, regardless of its type.
+ */
+sentry_uuid_t sentry__capture_event(sentry_value_t event);
+
 /**
  * This function will submit the `envelope` to the given `transport`, first
  * checking for consent.