Initial implementation of relnotes handler

src/github.rs

@@ -166,6 +166,34 @@ impl GithubClient {
         let (body, _req_dbg) = self.send_req(req).await?;
         Ok(serde_json::from_slice(&body)?)
     }
+
+    pub(crate) async fn new_issue(
+        &self,
+        repo: &IssueRepository,
+        title: &str,
+        body: &str,
+        labels: Vec<String>,
+    ) -> anyhow::Result<NewIssueResponse> {
+        #[derive(serde::Serialize)]
+        struct NewIssue<'a> {
+            title: &'a str,
+            body: &'a str,
+            labels: Vec<String>,
+        }
+        let url = format!("{}/issues", repo.url(&self));
+        self.json(self.post(&url).json(&NewIssue {
+            title,
+            body,
+            labels,
+        }))
+        .await
+        .context("failed to create issue")
+    }
+}
+
+#[derive(Debug, serde::Deserialize)]
+pub struct NewIssueResponse {
+    pub number: u64,
 }
 
 impl User {
@@ -327,6 +355,7 @@ pub struct Issue {
     pub head: Option<CommitBase>,
     /// Whether it is open or closed.
     pub state: IssueState,
+    pub milestone: Option<Milestone>,
 }
 
 #[derive(Debug, serde::Deserialize, Eq, PartialEq)]
@@ -2509,7 +2538,7 @@ impl GithubClient {
     }
 
     /// Set the milestone of an issue or PR.
-    async fn set_milestone(
+    pub async fn set_milestone(
         &self,
         full_repo_name: &str,
         milestone: &Milestone,

src/handlers.rs

@@ -43,6 +43,7 @@ mod prioritize;
 pub mod project_goals;
 pub mod pull_requests_assignment_update;
 mod relabel;
+mod relnotes;
 mod review_requested;
 mod review_submitted;
 mod rfc_helper;
@@ -107,6 +108,14 @@ pub async fn handle(ctx: &Context, event: &Event) -> Vec<HandlerError> {
         );
     }
 
+    if let Err(e) = relnotes::handle(ctx, event).await {
+        log::error!(
+            "failed to process event {:?} with relnotes handler: {:?}",
+            event,
+            e
+        );
+    }
+
     if let Some(config) = config
         .as_ref()
         .ok()

src/handlers/relnotes.rs

@@ -0,0 +1,114 @@
+//! This handler implements collecting release notes from issues and PRs that are tagged with
+//! `relnotes`. Any such tagging will open a new issue in rust-lang/rust responsible for tracking
+//! the inclusion in releases notes.
+//!
+//! The new issue will be closed when T-release has added the text proposed (tracked in the issue
+//! description) into the final release notes PR.
+//!
+//! The issue description will be edited manually by teams through the GitHub UI -- in the future,
+//! we might add triagebot support for maintaining that text via commands or similar.
+//!
+//! These issues will also be automatically milestoned when their corresponding PR or issue is. In
+//! the absence of a milestone, T-release is responsible for ascertaining which release is
+//! associated with the issue.
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    db::issue_data::IssueData,
+    github::{Event, IssuesAction},
+    handlers::Context,
+};
+
+const RELNOTES_KEY: &str = "relnotes";
+
+#[derive(Debug, Default, Deserialize, Serialize)]
+struct RelnotesState {
+    relnotes_issue: Option<u64>,
+}
+
+pub async fn handle(ctx: &Context, event: &Event) -> anyhow::Result<()> {
+    let Event::Issue(e) = event else {
+        return Ok(());
+    };
+
+    let repo = e.issue.repository();
+    if !(repo.organization == "rust-lang" && repo.repository == "rust") {
+        return Ok(());
+    }
+
+    if e.issue
+        .title
+        .starts_with("Tracking issue for release notes")
+    {
+        // Ignore these issues -- they're otherwise potentially self-recursive.
+        return Ok(());
+    }
+
+    let mut client = ctx.db.get().await;
+    let mut state: IssueData<'_, RelnotesState> =
+        IssueData::load(&mut client, &e.issue, RELNOTES_KEY).await?;
+
+    if let Some(paired) = state.data.relnotes_issue {
+        // Already has a paired release notes issue.
+
+        if let IssuesAction::Milestoned = &e.action {
+            if let Some(milestone) = &e.issue.milestone {
+                ctx.github
+                    .set_milestone(&e.issue.repository().to_string(), &milestone, paired)
+                    .await?;
+            }
+        }
+
+        return Ok(());
+    }
+
+    if let IssuesAction::Labeled { label } = &e.action {
+        if label.name == "relnotes" || label.name == "relnotes-perf" {
+            let title = format!(
+                "Tracking issue for release notes of #{}: {}",
+                e.issue.number, e.issue.title
+            );
+            let body = format!(
+                "
+This issue tracks the release notes text for #{}.
+
+- [ ] Issue is nominated for the responsible team (and T-release nomination is removed).
+- [ ] Proposed text is drafted by team responsible for underlying change.
+- [ ] Issue is nominated for release team review of clarity for wider audience.
+- [ ] Release team includes text in release notes/blog posts.
+
+Release notes text:
+
+The section title will be de-duplicated by the release team with other release notes issues.
+Prefer to use the standard titles from [previous releases](https://doc.rust-lang.org/nightly/releases.html).
+More than one section can be included if needed.
+
+```markdown
+# Compatibility Notes
+- [{}]({})
+```
+
+Release blog section (if any, leave blank if no section is expected):
+
+```markdown
+```
+",
+                e.issue.number, e.issue.title, e.issue.html_url,
+            );
+            let resp = ctx
+                .github
+                .new_issue(
+                    &e.issue.repository(),
+                    &title,
+                    &body,
+                    vec!["relnotes".to_owned(), "I-release-nominated".to_owned()],
+                )
+                .await?;
+            state.data.relnotes_issue = Some(resp.number);
+            state.save().await?;
+        }
+    }
+
+    Ok(())
+}