Filtering to 'opened' pull request events.

src/githubctl/pull_request_event.rs

@@ -1,12 +1,26 @@
+use crate::json_util::get_json_object;
 use crate::json_util::get_json_string;
 
 pub struct PullRequestEvent<'a> {
     original_event: &'a serde_json::Value,
+    pub action: &'a String,
 }
 
 impl<'a> PullRequestEvent<'a> {
     pub fn new(original_event: &'a serde_json::Value) -> Result<Self, Box<dyn std::error::Error>> {
-        Ok(PullRequestEvent { original_event })
+        let payload = original_event
+            .get("payload")
+            .map(get_json_object)
+            .expect("Ran into a PullRequestEvent without a payload.");
+        let action = payload
+            .get("action")
+            .map(get_json_string)
+            .expect("Ran into a PullRequestEvent without a payload.action.");
+
+        Ok(PullRequestEvent {
+            original_event,
+            action,
+        })
     }
 
     pub fn is_a(event: &'a serde_json::Value) -> Result<bool, Box<dyn std::error::Error>> {