[llvm] [GitHub] Add Greeting comment to new PRs with useful information (PR #72249)

[David Spickett via llvm-commits]

https://github.com/DavidSpickett created https://github.com/llvm/llvm-project/pull/72249

This adds a new workflow that responds to PRs that are opened with a comment thanking the author for their contribution, and provides answers to common problems (problem for now, could expand later).

According to my testing, and the docs here:
https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target

`opened` will only trigger on the first opening, not a re-open.

I considered including this comment in the one the labeller adds, but that means that it would be emailed to all subscribers not just the author.

Though it's still possible that this workflow would end up commenting after another one, in which case subscribers would get a notification.

>From ea1f031f06b6701699a20a5937103dde774b1cb2 Mon Sep 17 00:00:00 2001
From: David Spickett <david.spickett at linaro.org>
Date: Mon, 13 Nov 2023 13:18:16 +0000
Subject: [PATCH] [GitHub] Add Greeting comment to new PRs with useful
 information

This adds a new workflow that responds to PRs that are opened
with a comment thanking the author for their contribution, and
provides answers to common problems (problem for now, could expand later).

According to my testing, and the docs here:
https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target

`opened` will only trigger on the first opening, not a re-open.

I considered including this comment in the one the labeller adds,
but that means that it would be emailed to all subscribers not just
the author.

Though it's still possible that this workflow would end up commenting
after another one, in which case subscribers would get a notification.
---
 .github/workflows/pr-greeter.yml    | 27 ++++++++++++++++++++++
 llvm/utils/git/github-automation.py | 35 +++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 .github/workflows/pr-greeter.yml

diff --git a/.github/workflows/pr-greeter.yml b/.github/workflows/pr-greeter.yml
new file mode 100644
index 000000000000000..9bc7ed734ccd34e
--- /dev/null
+++ b/.github/workflows/pr-greeter.yml
@@ -0,0 +1,27 @@
+name: PR Greeter
+
+on:
+  pull_request_target:
+   types: [ opened ]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  greet:
+    runs-on: ubuntu-latest
+    if: github.repository == 'llvm/llvm-project'
+    steps:
+      - name: Setup Automation Script
+        run: |
+          curl -O -L --fail https://raw.githubusercontent.com/"$GITHUB_REPOSITORY"/main/llvm/utils/git/github-automation.py
+          curl -O -L --fail https://raw.githubusercontent.com/"$GITHUB_REPOSITORY"/main/llvm/utils/git/requirements.txt
+          chmod a+x github-automation.py
+          pip install -r requirements.txt
+
+      - name: Greet Author
+        run: |
+          ./github-automation.py \
+            --token '${{ secrets.GITHUB_TOKEN }}' \
+            pr-greeter \
+            --issue-number "${{ github.event.pull_request.number }}"
diff --git a/llvm/utils/git/github-automation.py b/llvm/utils/git/github-automation.py
index ad1878d41193920..be4962b8093ce9e 100755
--- a/llvm/utils/git/github-automation.py
+++ b/llvm/utils/git/github-automation.py
@@ -211,6 +211,35 @@ def _get_curent_team(self) -> Optional[github.Team.Team]:
         return None
 
 
+class PRGreeter:
+    def __init__(self, token: str, repo: str, pr_number: int):
+        repo = github.Github(token).get_repo(repo)
+        self.pr = repo.get_issue(pr_number).as_pull_request()
+
+    def run(self) -> bool:
+        # We assume that this is only called for a PR that has just been opened.
+
+        # This text is using Markdown formatting.
+        comment = f"""\
+Thank you for submitting a Pull Request (PR) to the LLVM Project!
+
+You can add reviewers by using the "Reviewers" section on this page.
+
+If this is not working for you, it's probably because you don't have write
+permissions for the repository. In which case you can instead tag reviewers by
+name in a comment by using `@` followed by their GitHub username.
+
+If you have received no comments on your PR for a week, you can request a review
+by "ping"ing the PR by adding a comment “Ping”. The common courtesy "ping" rate
+is once a week. Please remember that you are asking for valuable time from other developers.
+
+If you have further questions, they may be answered by the [LLVM GitHub User Guide](https://llvm.org/docs/GitHub.html).
+
+You can also ask questions in a comment on this PR, on the [LLVM Discord](https://discord.com/invite/xS7Z362) or on the [forums](https://discourse.llvm.org/)."""
+        self.pr.as_issue().create_comment(comment)
+        return True
+
+
 def setup_llvmbot_git(git_dir="."):
     """
     Configure the git repo in `git_dir` with the llvmbot account so
@@ -655,6 +684,9 @@ def execute_command(self) -> bool:
 pr_subscriber_parser.add_argument("--label-name", type=str, required=True)
 pr_subscriber_parser.add_argument("--issue-number", type=int, required=True)
 
+pr_greeter_parser = subparsers.add_parser("pr-greeter")
+pr_greeter_parser.add_argument("--issue-number", type=int, required=True)
+
 release_workflow_parser = subparsers.add_parser("release-workflow")
 release_workflow_parser.add_argument(
     "--llvm-project-dir",
@@ -705,6 +737,9 @@ def execute_command(self) -> bool:
         args.token, args.repo, args.issue_number, args.label_name
     )
     pr_subscriber.run()
+elif args.command == "pr-greeter":
+    pr_greeter = PRGreeter(args.token, args.repo, args.issue_number)
+    pr_greeter.run()
 elif args.command == "release-workflow":
     release_workflow = ReleaseWorkflow(
         args.token,