Add a rendered list of the full stack to PR descriptions

Requires a change to the main update logic: we now need to
always update every PR, since we need to update the messages
of lower PRs when an upper PR is changed.

Also, when creating new PRs, the list of stacked PRs would
be incomplete. Queue all mutations and execute them at the
end to fix this.

Fixes #139

commit-id:28b937ff

github/githubclient/client.go

@@ -1,6 +1,7 @@
 package githubclient
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"net/url"
@@ -181,7 +182,7 @@ func (c *client) CreatePullRequest(ctx context.Context,
 			}
 		} `graphql:"createPullRequest(input: $input)"`
 	}
-	commitBody := githubv4.String(commit.Body)
+	commitBody := githubv4.String(formatBody(commit, info.PullRequests))
 	input := githubv4.CreatePullRequestInput{
 		RepositoryID: info.RepositoryID,
 		BaseRefName:  githubv4.String(baseRefName),
@@ -214,6 +215,22 @@ func (c *client) CreatePullRequest(ctx context.Context,
 	return pr
 }
 
+func formatStackMarkdown(stack []*github.PullRequest) string {
+	var buf bytes.Buffer
+	for i := len(stack) - 1; i >= 0; i-- {
+		buf.WriteString(fmt.Sprintf("- #%d\n", stack[i].Number))
+	}
+
+	return buf.String()
+}
+
+func formatBody(commit git.Commit, stack []*github.PullRequest) string {
+	if len(stack) <= 1 {
+		return commit.Body
+	}
+	return fmt.Sprintf("**Stack**:\n%s\n\n%s", formatStackMarkdown(stack), commit.Body)
+}
+
 func (c *client) UpdatePullRequest(ctx context.Context,
 	info *github.GitHubInfo, pr *github.PullRequest, commit git.Commit, prevCommit *git.Commit) {
 
@@ -239,7 +256,7 @@ func (c *client) UpdatePullRequest(ctx context.Context,
 	}
 	baseRefNameStr := githubv4.String(baseRefName)
 	subject := githubv4.String(commit.Subject)
-	body := githubv4.String(commit.Body)
+	body := githubv4.String(formatBody(commit, info.PullRequests))
 	input := githubv4.UpdatePullRequestInput{
 		PullRequestID: pr.ID,
 		BaseRefName:   &baseRefNameStr,

spr/spr.go

@@ -109,9 +109,7 @@ func (sd *stackediff) UpdatePullRequests(ctx context.Context) {
 	}
 	githubInfo.PullRequests = validPullRequests
 
-	reorder := false
 	if commitsReordered(localCommits, githubInfo.PullRequests) {
-		reorder = true
 		// if commits have been reordered :
 		//   first - rebase all pull requests to target branch
 		//   then - update all pull requests
@@ -124,6 +122,14 @@ func (sd *stackediff) UpdatePullRequests(ctx context.Context) {
 	sd.syncCommitStackToGitHub(ctx, localCommits, githubInfo)
 	sd.profiletimer.Step("UpdatePullRequests::SyncCommitStackToGithub")
 
+	type prUpdate struct {
+		pr         *github.PullRequest
+		commit     git.Commit
+		prevCommit *git.Commit
+	}
+
+	updateQueue := make([]prUpdate, 0)
+
 	// iterate through local_commits and update pull_requests
 	for commitIndex, c := range localCommits {
 		if c.WIP {
@@ -133,18 +139,12 @@ func (sd *stackediff) UpdatePullRequests(ctx context.Context) {
 		for _, pr := range githubInfo.PullRequests {
 			if c.CommitID == pr.Commit.CommitID {
 				prFound = true
-				if c.CommitHash != pr.Commit.CommitHash || reorder {
-					// if commit id is same but commit hash changed it means the commit
-					//  has been amended and we need to update the pull request
-					// in the reorder case we also want to update the pull request
-
-					var prevCommit *git.Commit
-					if commitIndex > 0 {
-						prevCommit = &localCommits[commitIndex-1]
-					}
-					sd.github.UpdatePullRequest(ctx, githubInfo, pr, c, prevCommit)
-					pr.Commit = c
+				var prevCommit *git.Commit
+				if commitIndex > 0 {
+					prevCommit = &localCommits[commitIndex-1]
 				}
+				updateQueue = append(updateQueue, prUpdate{pr, c, prevCommit})
+				pr.Commit = c
 				break
 			}
 		}
@@ -157,10 +157,17 @@ func (sd *stackediff) UpdatePullRequests(ctx context.Context) {
 			}
 			pr := sd.github.CreatePullRequest(ctx, githubInfo, c, prevCommit)
 			githubInfo.PullRequests = append(githubInfo.PullRequests, pr)
+			updateQueue = append(updateQueue, prUpdate{pr, c, prevCommit})
 		}
 	}
 	sd.profiletimer.Step("UpdatePullRequests::updatePullRequests")
 
+	for _, pr := range updateQueue {
+		sd.github.UpdatePullRequest(ctx, githubInfo, pr.pr, pr.commit, pr.prevCommit)
+	}
+
+	sd.profiletimer.Step("UpdatePullRequests::commitUpdateQueue")
+
 	sd.StatusPullRequests(ctx)
 }