Automatically add beta nominated to issues fixing regressions

... from stable to beta

src/github.rs

@@ -749,6 +749,20 @@ pub struct Repository {
 impl Repository {
     const GITHUB_API_URL: &'static str = "https://api.github.com";
 
+    pub async fn get_issue(&self, client: &GithubClient, id: u64) -> anyhow::Result<Issue> {
+        let url = format!(
+            "{}/repos/{}/issues/{}",
+            Repository::GITHUB_API_URL,
+            self.full_name,
+            id
+        );
+        let result = client.get(&url);
+        client
+            .json(result)
+            .await
+            .with_context(|| format!("failed to get issue from {}", url))
+    }
+
     pub async fn get_issues<'a>(
         &self,
         client: &GithubClient,

src/handlers.rs

@@ -25,6 +25,7 @@ impl fmt::Display for HandlerError {
 
 mod assign;
 mod autolabel;
+mod beta_backport;
 mod close;
 mod github_releases;
 mod glacier;
@@ -74,6 +75,14 @@ pub async fn handle(ctx: &Context, event: &Event) -> Vec<HandlerError> {
         );
     }
 
+    if let Err(e) = beta_backport::handle(ctx, event).await {
+        log::error!(
+            "failed to process event {:?} with beta_backport handler: {:?}",
+            event,
+            e
+        );
+    }
+
     if let Some(ghr_config) = config
         .as_ref()
         .ok()

src/handlers/beta_backport.rs

@@ -0,0 +1,52 @@
+use crate::github::{Event, IssuesAction, Label};
+use crate::handlers::Context;
+use regex::Regex;
+
+lazy_static! {
+    // See https://docs.github.com/en/issues/tracking-your-work-with-issues/creating-issues/linking-a-pull-request-to-an-issue
+    // Max 19 digits long to prevent u64 overflow
+    static ref CLOSES_ISSUE: Regex = Regex::new("(close[sd]|fix(e[sd])?|resolve[sd]) #(\\d{1,19})").unwrap();
+}
+
+pub(crate) async fn handle(
+    ctx: &Context,
+    event: &Event,
+) -> anyhow::Result<()> {
+    let issue_event = if let Event::Issue(event) = event {
+        event
+    } else {
+        return Ok(());
+    };
+
+    if issue_event.action != IssuesAction::Opened {
+        return Ok(());
+    }
+
+    if issue_event.issue.pull_request.is_none() {
+        return Ok(());
+    }
+
+    for caps in CLOSES_ISSUE.captures_iter(&issue_event.issue.body) {
+        // Should never fail due to the regex
+        let issue_id = caps.get(1).unwrap().as_str().parse::<u64>().unwrap();
+        let issue = issue_event
+            .repository
+            .get_issue(&ctx.github, issue_id)
+            .await?;
+        if issue.labels.contains(&Label {
+            name: "regression-from-stable-to-beta".to_string(),
+        }) {
+            let mut labels = issue_event.issue.labels().to_owned();
+            labels.push(Label {
+                name: "beta-nominated".to_string(),
+            });
+            issue_event
+                .issue
+                .set_labels(&ctx.github, labels)
+                .await?;
+            break;
+        }
+    }
+
+    Ok(())
+}