Merge pull request #1702 from ehuss/docs-update-trigger

Add ability to trigger docs-update via Zulip

Author: Mark-Simulacrum

src/actions.rs

@@ -112,6 +112,7 @@ impl<'a> Action for Step<'a> {
                     // These are unused for query.
                     default_branch: "master".to_string(),
                     fork: false,
+                    parent: None,
                 };
 
                 for QueryMap { name, kind, query } in queries {

src/github.rs

@@ -987,6 +987,7 @@ pub struct Repository {
     pub default_branch: String,
     #[serde(default)]
     pub fork: bool,
+    pub parent: Option<Box<Repository>>,
 }
 
 #[derive(Copy, Clone)]
@@ -1485,16 +1486,66 @@ impl Repository {
     }
 
     /// Synchronize a branch (in a forked repository) by pulling in its upstream contents.
+    ///
+    /// **Warning**: This will to a force update if there are conflicts.
     pub async fn merge_upstream(&self, client: &GithubClient, branch: &str) -> anyhow::Result<()> {
         let url = format!("{}/merge-upstream", self.url());
-        client
+        let merge_error = match client
             .send_req(client.post(&url).json(&serde_json::json!({
                 "branch": branch,
             })))
             .await
+        {
+            Ok(_) => return Ok(()),
+            Err(e) => {
+                if e.downcast_ref::<reqwest::Error>().map_or(false, |e| {
+                    matches!(
+                        e.status(),
+                        Some(StatusCode::UNPROCESSABLE_ENTITY | StatusCode::CONFLICT)
+                    )
+                }) {
+                    e
+                } else {
+                    return Err(e);
+                }
+            }
+        };
+        // 409 is a clear error that there is a merge conflict.
+        // However, I don't understand how/why 422 might happen. The docs don't really say.
+        // The gh cli falls back to trying to force a sync, so let's try that.
+        log::info!(
+            "{} failed to merge upstream branch {branch}, trying force sync: {merge_error:?}",
+            self.full_name
+        );
+        let parent = self.parent.as_ref().ok_or_else(|| {
+            anyhow::anyhow!(
+                "{} failed to merge upstream branch {branch}, \
+                 force sync could not determine parent",
+                self.full_name
+            )
+        })?;
+        // Note: I'm not sure how to handle the case where the branch name
+        // differs to the upstream. For example, if I create a branch off
+        // master in my fork, somehow GitHub knows that my branch should push
+        // to upstream/master (not upstream/my-branch-name). I can't find a
+        // way to find that branch name. Perhaps GitHub assumes it is the
+        // default branch if there is no matching branch name?
+        let branch_ref = format!("heads/{branch}");
+        let latest_parent_commit = parent
+            .get_reference(client, &branch_ref)
+            .await
+            .with_context(|| {
+                format!(
+                    "failed to get head branch {branch} when merging upstream to {}",
+                    self.full_name
+                )
+            })?;
+        let sha = latest_parent_commit.object.sha;
+        self.update_reference(client, &branch_ref, &sha)
+            .await
             .with_context(|| {
                 format!(
-                    "{} failed to merge upstream branch {branch}",
+                    "failed to force update {branch} to {sha} for {}",
                     self.full_name
                 )
             })?;

src/handlers/docs_update.rs

@@ -1,7 +1,7 @@
 //! A scheduled job to post a PR to update the documentation on rust-lang/rust.
 
 use crate::db::jobs::JobSchedule;
-use crate::github::{self, GitTreeEntry, GithubClient, Repository};
+use crate::github::{self, GitTreeEntry, GithubClient, Issue, Repository};
 use anyhow::Context;
 use anyhow::Result;
 use cron::Schedule;
@@ -56,10 +56,13 @@ pub async fn handle_job() -> Result<()> {
     }
 
     tracing::trace!("starting docs-update");
-    docs_update().await.context("failed to process docs update")
+    docs_update()
+        .await
+        .context("failed to process docs update")?;
+    Ok(())
 }
 
-async fn docs_update() -> Result<()> {
+pub async fn docs_update() -> Result<Option<Issue>> {
     let gh = GithubClient::new_with_default_token(Client::new());
     let work_repo = gh.repository(WORK_REPO).await?;
     work_repo
@@ -69,12 +72,11 @@ async fn docs_update() -> Result<()> {
     let updates = get_submodule_updates(&gh, &work_repo).await?;
     if updates.is_empty() {
         tracing::trace!("no updates this week?");
-        return Ok(());
+        return Ok(None);
     }
 
     create_commit(&gh, &work_repo, &updates).await?;
-    create_pr(&gh, &updates).await?;
-    Ok(())
+    Ok(Some(create_pr(&gh, &updates).await?))
 }
 
 struct Update {
@@ -184,7 +186,7 @@ async fn create_commit(
     Ok(())
 }
 
-async fn create_pr(gh: &GithubClient, updates: &[Update]) -> Result<()> {
+async fn create_pr(gh: &GithubClient, updates: &[Update]) -> Result<Issue> {
     let dest_repo = gh.repository(DEST_REPO).await?;
     let mut body = String::new();
     for update in updates {
@@ -197,5 +199,5 @@ async fn create_pr(gh: &GithubClient, updates: &[Update]) -> Result<()> {
         .new_pr(gh, TITLE, &head, &dest_repo.default_branch, &body)
         .await?;
     tracing::debug!("created PR {}", pr.html_url);
-    Ok(())
+    Ok(pr)
 }