From 556982ad8bdf9228ededf5ba98b633ed5dd01476 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Brey=20Vilas?= <alvaro.brey@nextcloud.com>
Date: Fri, 24 Sep 2021 14:07:11 +0200
Subject: [PATCH] Add simple git hooks and gradle task to install them
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 - Pre-commit hook checks ktlint and detekt
 - Pre-push hook checks signoff

Signed-off-by: Álvaro Brey Vilas <alvaro.brey@nextcloud.com>
---
 CONTRIBUTING.md          |  8 ++++++++
 build.gradle             |  7 +++++++
 scripts/hooks/pre-commit |  6 ++++++
 scripts/hooks/pre-push   | 31 +++++++++++++++++++++++++++++++
 4 files changed, 52 insertions(+)
 create mode 100755 scripts/hooks/pre-commit
 create mode 100755 scripts/hooks/pre-push

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c578bd3b29..519ea35ab2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -119,6 +119,14 @@ There are three build variants
 * gplay: with Google Stuff (Push notification), used for Google Play Store
 * versionDev: based on master and library master, available as direct download and FDroid
 
+### Git hooks
+We provide git hooks to make development process easier for both the developer and the reviewers.
+To install them, just run:
+
+```bash
+./gradlew installGitHooks
+```
+
 ## Contribution process
 * Contribute your code in the branch 'master'. It will give us a better chance to test your code before merging it with stable code.
 * For your first contribution start a pull request on master.
diff --git a/build.gradle b/build.gradle
index 37c0613443..1c61e7caa7 100644
--- a/build.gradle
+++ b/build.gradle
@@ -440,6 +440,13 @@ task ktlintFormat(type: JavaExec, group: "formatting") {
     args "-F", "src/**/*.kt"
 }
 
+task installGitHooks(type: Copy) {
+    from('scripts/hooks') {
+        include '*'
+    }
+    into '.git/hooks'
+}
+
 detekt {
     reports {
         xml {
diff --git a/scripts/hooks/pre-commit b/scripts/hooks/pre-commit
new file mode 100755
index 0000000000..4707b2d632
--- /dev/null
+++ b/scripts/hooks/pre-commit
@@ -0,0 +1,6 @@
+#!/bin/bash
+# Pre-commit hook: don't allow commits if detekt or ktlint fail. Skip with "git commit --no-verify".
+set -euo pipefail
+
+./gradlew --daemon --quiet detekt
+./gradlew --daemon --quiet ktlint
diff --git a/scripts/hooks/pre-push b/scripts/hooks/pre-push
new file mode 100755
index 0000000000..aaaa929bfb
--- /dev/null
+++ b/scripts/hooks/pre-push
@@ -0,0 +1,31 @@
+#!/bin/bash
+# Pre-push: Don't allow commits without Signed-off-by. Skip with "git push --no-verify".
+set -euo pipefail
+
+z40=0000000000000000000000000000000000000000 # magic deleted ref
+
+while read local_ref local_sha remote_ref remote_sha
+do
+	if [ "$local_sha" != $z40 ]
+	then
+		if [ "$remote_sha" = $z40 ]
+		then
+			# New branch, examine all commits
+			range="$(git merge-base master $local_sha)..$local_sha"
+		else
+			# Update to existing branch, examine new commits
+			range="$remote_sha..$local_sha"
+		fi
+
+		# Check for WIP commit
+		commit=$(git rev-list --grep 'Signed-off-by' --invert-grep "$range")
+		if [ -n "$commit" ]
+		then
+			echo >&2 "Found commits without signoff in $local_ref. Aborting push. Offending commits:"
+			echo >&2 "$commit"
+			exit 1
+		fi
+	fi
+done
+
+exit 0