From d974196464490dda8c6ce78acb82cff114010c3c Mon Sep 17 00:00:00 2001
From: David Leal <halfpacho@gmail.com>
Date: Mon, 17 Jul 2023 12:02:37 -0600
Subject: [PATCH] Delete branches if they're already merged (#39)

---
 README.md  | 10 +++++++++-
 action.yml | 23 +++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index a8e5d40..4422de2 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0 # This pulls changes before doing any changes
-      - uses: Panquesito7/submodules-alternative@v1.5.4
+      - uses: Panquesito7/submodules-alternative@v1.5.5
         with:
           repos_filename: repos                       # In case your file is named `repos.lua`, you can leave it as `repos`.
           use_pr: true                                # Whether to create a pull request when updating/adding the repositories.
@@ -77,8 +77,16 @@ jobs:
           update_repos: true                          # When enabled, this will attempt to update all the repositories.
           squash_commits: false                       # Whether to squash all commits or not on every repository update/addition. Cannot be used if `one_pr` is disabled.
           one_pr: false                               # Creates one single PR for everything if enabled. Works only for `update_repos` if disabled.
+          delete_existing_branches: true              # Deletes the branches that updated the subtrees. Note that this is done only on action run, not on immediate PR merge.
 ```
 
+If `delete_existing_branches` is enabled, it will attempt to delete the branches before running the scripts to ensure there are no merge conflicts.\
+However, this is not the most efficient way of deleting the branches. These are other alternatives I recommend:
+
+1. Automatically [delete branches](https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/configuring-pull-request-merges/managing-the-automatic-deletion-of-branches) on PR merging (recommended).
+2. Manually delete the branches (not recommended).
+3. Use a GitHub Action like [Delete Merged Branch](https://github.com/SvanBoxel/delete-merged-branch).
+
 You can also configure to run the workflow manually by using `workflow_dispatch` instead of `schedule`.\
 For more information about Cron, you can check [CronHub](https://crontab.cronhub.io/).
 
diff --git a/action.yml b/action.yml
index 50eee2e..15662e1 100644
--- a/action.yml
+++ b/action.yml
@@ -41,6 +41,10 @@ inputs:
     description: "Creates one single PR for updating all the repositories. This does not apply to the `fetch-repos` script. `squash_commits` must be disabled!"
     required: false
     default: "false"
+  delete_existing_branches:
+    description: "Deletes the branches that updated the subtrees. Note that this is done only on action run, not on immediate PR merge."
+    required: false
+    default: "true"
 runs:
   using: "composite"
   steps:
@@ -99,6 +103,25 @@ runs:
             wget https://raw.githubusercontent.com/Panquesito7/submodules-alternative/main/update-repos.lua
           fi
         fi
+    - name: Delete existing branches
+      shell: bash
+      run: |
+        if [[ ${{ inputs.update_repos }} == true ]] && [[ ${{ inputs.delete_existing_branches }} == true ]]; then
+          branches=$(lua -e 'local repos = require("${{ inputs.repos_filename }}").repos; dofile("helper-functions.lua"); get_repo_branches(repos)')
+          for branch in ${branches[@]}; do
+            if git ls-remote --heads origin $branch | grep -q $branch; then
+              if git diff --name-only origin/${GITHUB_REF##*/} $branch | grep -q $branch; then
+                git push origin -d $branch
+              fi
+            fi
+          done
+
+          if git ls-remote --heads origin ${{ inputs.branch_name }} | grep -q ${{ inputs.branch_name }}; then
+            if git diff --name-only origin/${GITHUB_REF##*/} ${{ inputs.branch_name }} | grep -q ${{ inputs.branch_name }}; then
+              git push origin -d ${{ inputs.branch_name }}
+            fi
+          fi
+        fi
     - name: Clone repositories
       shell: bash
       run: |