From 6b77c8f77059208b780f314f26e1ca427f564f20 Mon Sep 17 00:00:00 2001
From: David Davis <daviddavis@redhat.com>
Date: Thu, 9 Sep 2021 13:53:26 -0400
Subject: [PATCH] Add a single commit check workflow

[noissue]
---
 .github/workflows/check_commits.yaml         | 14 ++++++++++++++
 CHANGES/494.feature                          |  1 +
 README.md                                    |  2 ++
 plugin-template                              |  1 +
 templates/github/.github/workflows/ci.yml.j2 | 17 +++++++++++++++++
 5 files changed, 35 insertions(+)
 create mode 100644 CHANGES/494.feature

diff --git a/.github/workflows/check_commits.yaml b/.github/workflows/check_commits.yaml
index c29bf715..499960c6 100644
--- a/.github/workflows/check_commits.yaml
+++ b/.github/workflows/check_commits.yaml
@@ -2,6 +2,20 @@
 name: Check Commit
 on: pull_request
 jobs:
+  single_commit:
+    name: Assert single commit
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      with:
+        fetch-depth: 30
+    - name: Checkout master
+      run: git fetch origin master
+    - name: create local master branch
+      run: git branch master origin/master
+    - name: Commit Count Check
+      run: test `git log  --oneline --no-merges HEAD ^master  | wc -l ` = 1
+    runs-on: ubuntu-latest
   test:
     runs-on: ubuntu-latest
     steps:
diff --git a/CHANGES/494.feature b/CHANGES/494.feature
new file mode 100644
index 00000000..4037277e
--- /dev/null
+++ b/CHANGES/494.feature
@@ -0,0 +1 @@
+Added a workflow to check that PRs contain a single commit.
diff --git a/README.md b/README.md
index 45c2fb83..db4e8a1f 100644
--- a/README.md
+++ b/README.md
@@ -209,6 +209,8 @@ The following settings are stored in `template_config.yml`.
 
   noissue_marker        A string that is used to mark a commit as not attached to an issue.
 
+  single_commit_check   Runs a job to check whether a PR contains a single commit or not.
+
   sync_ci               Enables a nightly workflow to update the CI files.
 
   test_bindings         Include a job that runs a script to test generated client
diff --git a/plugin-template b/plugin-template
index 2b56819c..3b6e6d0a 100755
--- a/plugin-template
+++ b/plugin-template
@@ -60,6 +60,7 @@ DEFAULT_SETTINGS = {
     "release_user": "pulpbot",
     "release_email": "pulp-infra@redhat.com",
     "noissue_marker": "[noissue]",
+    "single_commit_check": True,
     "sync_ci": True,
     "test_bindings": True,
     "test_cli": False,
diff --git a/templates/github/.github/workflows/ci.yml.j2 b/templates/github/.github/workflows/ci.yml.j2
index a04c2e6a..80a6e15e 100644
--- a/templates/github/.github/workflows/ci.yml.j2
+++ b/templates/github/.github/workflows/ci.yml.j2
@@ -17,6 +17,23 @@ jobs:
 
 {% if pre_job_template -%}{{ "  " | indent }}{% include pre_job_template.path %}{%- endif %}
 
+  {%- if single_commit_check %}
+  single_commit:
+    name: Assert single commit
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      with:
+        fetch-depth: 30
+    - name: Checkout {{ plugin_default_branch }}
+      run: git fetch origin {{ plugin_default_branch }}
+    - name: create local {{ plugin_default_branch }} branch
+      run: git branch {{ plugin_default_branch }} origin/{{ plugin_default_branch }}
+    - name: Commit Count Check
+      run: test `git log  --oneline --no-merges HEAD ^{{ plugin_default_branch }}  | wc -l ` = 1
+    runs-on: ubuntu-latest
+  {%- endif %}
+
   lint:
     runs-on: ubuntu-latest
     {% if pre_job_template %}needs: {{ pre_job_template.name }}{% endif %}