feat: unapprove on edit

Author: vohoanglong0107

src/bors/event.rs

@@ -1,11 +1,13 @@
 use crate::database::{WorkflowStatus, WorkflowType};
-use crate::github::{CommitSha, GithubRepoName, GithubUser, PullRequestNumber};
+use crate::github::{CommitSha, GithubRepoName, GithubUser, PullRequest, PullRequestNumber};
 use octocrab::models::RunId;
 
 #[derive(Debug)]
 pub enum BorsRepositoryEvent {
     /// A comment was posted on a pull request.
     Comment(PullRequestComment),
+    /// When the pull request is edited by its author
+    PullRequestEdited(PullRequestEdited),
     /// A workflow run on Github Actions or a check run from external CI system has been started.
     WorkflowStarted(WorkflowStarted),
     /// A workflow run on Github Actions or a check run from external CI system has been completed.
@@ -22,6 +24,7 @@ impl BorsRepositoryEvent {
             BorsRepositoryEvent::WorkflowStarted(workflow) => &workflow.repository,
             BorsRepositoryEvent::WorkflowCompleted(workflow) => &workflow.repository,
             BorsRepositoryEvent::CheckSuiteCompleted(payload) => &payload.repository,
+            BorsRepositoryEvent::PullRequestEdited(payload) => &payload.repository,
         }
     }
 }
@@ -50,6 +53,13 @@ pub struct PullRequestComment {
     pub text: String,
 }
 
+#[derive(Debug)]
+pub struct PullRequestEdited {
+    pub repository: GithubRepoName,
+    pub pull_request: PullRequest,
+    pub from_base_sha: Option<CommitSha>,
+}
+
 #[derive(Debug)]
 pub struct WorkflowStarted {
     pub repository: GithubRepoName,

src/bors/handlers/mod.rs

@@ -8,7 +8,9 @@ use crate::bors::event::{BorsGlobalEvent, BorsRepositoryEvent, PullRequestCommen
 use crate::bors::handlers::help::command_help;
 use crate::bors::handlers::ping::command_ping;
 use crate::bors::handlers::refresh::refresh_repository;
-use crate::bors::handlers::review::{command_approve, command_unapprove};
+use crate::bors::handlers::review::{
+    command_approve, command_unapprove, handle_pull_request_edited,
+};
 use crate::bors::handlers::trybuild::{command_try_build, command_try_cancel, TRY_BRANCH_NAME};
 use crate::bors::handlers::workflow::{
     handle_check_suite_completed, handle_workflow_completed, handle_workflow_started,
@@ -112,6 +114,14 @@ pub async fn handle_bors_repository_event(
                 .instrument(span.clone())
                 .await?;
         }
+        BorsRepositoryEvent::PullRequestEdited(payload) => {
+            let span =
+                tracing::info_span!("Pull request edited", repo = payload.repository.to_string());
+
+            handle_pull_request_edited(repo, db, payload)
+                .instrument(span.clone())
+                .await?;
+        }
     }
     Ok(())
 }

src/bors/handlers/review.rs

@@ -1,12 +1,15 @@
 use std::sync::Arc;
 
 use crate::bors::command::Approver;
+use crate::bors::event::PullRequestEdited;
 use crate::bors::handlers::labels::handle_label_trigger;
 use crate::bors::Comment;
 use crate::bors::RepositoryState;
+use crate::github::CommitSha;
 use crate::github::GithubUser;
 use crate::github::LabelTrigger;
 use crate::github::PullRequest;
+use crate::github::PullRequestNumber;
 use crate::permissions::PermissionType;
 use crate::PgDbClient;
 
@@ -52,6 +55,21 @@ pub(super) async fn command_unapprove(
     notify_of_unapproval(&repo_state, pr).await
 }
 
+pub(super) async fn handle_pull_request_edited(
+    repo_state: Arc<RepositoryState>,
+    db: Arc<PgDbClient>,
+    payload: PullRequestEdited,
+) -> anyhow::Result<()> {
+    // If the base branch has changed, unapprove the PR
+    let Some(_) = payload.from_base_sha else {
+        return Ok(());
+    };
+    let pr_number = payload.pull_request.number;
+    db.unapprove(repo_state.repository(), pr_number).await?;
+    handle_label_trigger(&repo_state, pr_number, LabelTrigger::Unapproved).await?;
+    notify_of_edited_pr(&repo_state, pr_number, payload.pull_request.head.sha).await
+}
+
 fn sufficient_approve_permission(repo: Arc<RepositoryState>, author: &GithubUser) -> bool {
     repo.permissions
         .load()
@@ -135,6 +153,23 @@ async fn notify_of_unapproval(repo: &RepositoryState, pr: &PullRequest) -> anyho
         .await
 }
 
+async fn notify_of_edited_pr(
+    repo: &RepositoryState,
+    pr_number: PullRequestNumber,
+    head_sha: CommitSha,
+) -> anyhow::Result<()> {
+    repo.client
+        .post_comment(
+            pr_number,
+            Comment::new(format!(
+                r#":warning: The base branch changed to `{}`, and the 
+PR will need to be re-approved."#,
+                head_sha
+            )),
+        )
+        .await
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{
@@ -226,7 +261,6 @@ approve = ["+approved"]
     }
 
     #[sqlx::test]
-    #[tracing_test::traced_test]
     async fn unapprove(pool: sqlx::PgPool) {
         let world = World::default();
         world.default_repo().lock().set_config(

src/github/webhook.rs

@@ -8,7 +8,8 @@ use axum::http::{HeaderMap, HeaderValue, StatusCode};
 use axum::{async_trait, RequestExt};
 use hmac::{Hmac, Mac};
 use octocrab::models::events::payload::{
-    IssueCommentEventAction, IssueCommentEventPayload, PullRequestReviewCommentEventAction,
+    IssueCommentEventAction, IssueCommentEventPayload, PullRequestEventAction,
+    PullRequestEventChangesFrom, PullRequestReviewCommentEventAction,
     PullRequestReviewCommentEventPayload,
 };
 use octocrab::models::pulls::{PullRequest, Review};
@@ -18,7 +19,7 @@ use sha2::Sha256;
 
 use crate::bors::event::{
     BorsEvent, BorsGlobalEvent, BorsRepositoryEvent, CheckSuiteCompleted, PullRequestComment,
-    WorkflowCompleted, WorkflowStarted,
+    PullRequestEdited, WorkflowCompleted, WorkflowStarted,
 };
 use crate::database::{WorkflowStatus, WorkflowType};
 use crate::github::server::ServerStateRef;
@@ -90,6 +91,26 @@ pub struct WebhookPullRequestReviewEvent<'a> {
     sender: Author,
 }
 
+/// Similar to PullRequestEvent from octocrab, but changes field also includes base sha.
+/// https://docs.github.com/en/webhooks/webhook-events-and-payloads#pull_request
+#[derive(Debug, serde::Deserialize)]
+struct WebhookPullRequestEvent {
+    action: PullRequestEventAction,
+    pull_request: PullRequest,
+    changes: Option<WebhookPullRequestChanges>,
+    repository: Repository,
+}
+
+#[derive(Debug, serde::Deserialize)]
+struct WebhookPullRequestChanges {
+    base: Option<WebhookPullRequestBaseChanges>,
+}
+
+#[derive(Debug, serde::Deserialize)]
+struct WebhookPullRequestBaseChanges {
+    sha: Option<PullRequestEventChangesFrom>,
+}
+
 /// axum extractor for GitHub webhook events.
 #[derive(Debug)]
 pub struct GitHubWebhook(pub BorsEvent);
@@ -149,6 +170,7 @@ fn parse_webhook_event(request: Parts, body: &[u8]) -> anyhow::Result<Option<Bor
 
     match event_type.as_bytes() {
         b"issue_comment" => parse_issue_comment_event(body),
+        b"pull_request" => parse_pull_request_events(body),
         b"pull_request_review" => parse_pull_request_review_events(body),
         b"pull_request_review_comment" => parse_pull_request_review_comment_events(body),
         b"installation_repositories" | b"installation" => Ok(Some(BorsEvent::Global(
@@ -179,6 +201,30 @@ fn parse_issue_comment_event(body: &[u8]) -> anyhow::Result<Option<BorsEvent>> {
     }
 }
 
+fn parse_pull_request_events(body: &[u8]) -> anyhow::Result<Option<BorsEvent>> {
+    let payload: WebhookPullRequestEvent = serde_json::from_slice(body)?;
+    let repository_name = parse_repository_name(&payload.repository)?;
+    if payload.action == PullRequestEventAction::Edited {
+        let Some(changes) = payload.changes else {
+            return Err(anyhow::anyhow!(
+                "Edited pull request event should have `changes` field"
+            ));
+        };
+        Ok(Some(BorsEvent::Repository(
+            BorsRepositoryEvent::PullRequestEdited(PullRequestEdited {
+                repository: repository_name,
+                pull_request: payload.pull_request.into(),
+                from_base_sha: changes
+                    .base
+                    .and_then(|base| base.sha)
+                    .map(|sha| CommitSha(sha.from)),
+            }),
+        )))
+    } else {
+        Ok(None)
+    }
+}
+
 fn parse_pull_request_review_events(body: &[u8]) -> anyhow::Result<Option<BorsEvent>> {
     let payload: WebhookPullRequestReviewEvent = serde_json::from_slice(body)?;
     if payload.action == "submitted" {