Mark PRs temporarily draft while submitting

src/stack_pr/cli.py

@@ -294,7 +294,7 @@ class StackEntry:
     _pr: str | None = None
     _base: str | None = None
     _head: str | None = None
-    need_update: bool = False
+    is_tmp_draft: bool = False
 
     @property
     def pr(self) -> str:
@@ -783,7 +783,7 @@ def toc_entry(se: StackEntry) -> str:
     return f"Stacked PRs:\n{''.join(entries)}\n"
 
 
-def get_current_pr_body(e: StackEntry) -> str:
+def get_pr_body(e: StackEntry) -> str:
     out = get_command_output(
         ["gh", "pr", "view", e.pr, "--json", "body"],
     )
@@ -815,7 +815,7 @@ def add_cross_links(st: list[StackEntry], *, keep_body: bool, verbose: bool) ->
 
         if keep_body:
             # Keep current body of the PR after the cross links component
-            current_pr_body = get_current_pr_body(e)
+            current_pr_body = get_pr_body(e)
             body_content = current_pr_body.split(CROSS_LINKS_DELIMETER, 1)[-1].lstrip()
 
         pr_body = [*header, body_content]
@@ -831,6 +831,13 @@ def add_cross_links(st: list[StackEntry], *, keep_body: bool, verbose: bool) ->
             raise RuntimeError
 
 
+def is_draft_pr(e: StackEntry) -> bool:
+    out = get_command_output(
+        ["gh", "pr", "view", e.pr, "--json", "isDraft"],
+    )
+    return json.loads(out)["isDraft"]
+
+
 # Temporarily set base branches of existing PRs to the bottom of the stack.
 # This needs to be done to avoid PRs getting closed when commits are
 # rearranged.
@@ -852,14 +859,21 @@ def add_cross_links(st: list[StackEntry], *, keep_body: bool, verbose: bool) ->
 # stack/2. If we push stack/1, then PR #2 gets automatically closed, since its
 # head branch will contain all the commits from its base branch.
 #
-# To avoid this, we temporarily set all base branches to point to 'main' - once
-# all the branches are pushed we can set the actual base branches.
+# To avoid this, we temporarily set all base branches to point to 'main'. To ensure
+# we don't accidentally notify reviewers in this transient state (where the PRs are
+# pointing to 'main'), we mark the PRs as draft - once all the branches are pushed
+# we can set the actual base branches and undraft the PRs.
 def reset_remote_base_branches(
     st: list[StackEntry], target: str, *, verbose: bool
 ) -> None:
     log(h("Resetting remote base branches"), level=2)
 
     for e in filter(lambda e: e.has_pr(), st):
+        # We need to check if the PR is already draft, otherwise we would
+        # unintentionally undo the draft status later.
+        if not is_draft_pr(e):
+            run_shell_command(["gh", "pr", "ready", e.pr, "--undo"], quiet=not verbose)
+            e.is_tmp_draft = True
         run_shell_command(["gh", "pr", "edit", e.pr, "-B", target], quiet=not verbose)
 
 
@@ -1117,6 +1131,12 @@ def command_submit(
     log(h("Adding cross-links to PRs"), level=1)
     add_cross_links(st, keep_body=keep_body, verbose=args.verbose)
 
+    # Undraft the PRs if they were marked as temporary drafts.
+    for e in st:
+        if e.is_tmp_draft:
+            run_shell_command(["gh", "pr", "ready", e.pr], quiet=not args.verbose)
+            e.is_tmp_draft = False
+
     if need_to_rebase_current:
         log(h(f"Rebasing the original branch '{current_branch}'"), level=2)
         run_shell_command(