Precommit hook that runs ktlint and detekt (#907)

Author: clementetb

.githooks/pre-push

@@ -0,0 +1,20 @@
+#!/bin/bash -e
+
+# Prevents pushing any code to the server that does not comply with klint or detekt
+# It ignores any unchecked files.
+
+# Ignore any unchecked file
+echo "Stashing changes before doing checks"
+git stash push -q -u --keep-index
+
+# Pop the stash once the scripts finishes, fails or gets cancelled
+function pop_stash() {
+    echo "Checks completed, popping stash"
+    git stash pop -q
+}
+
+trap "exit" INT TERM ERR
+trap pop_stash EXIT
+
+# Do the actual check ups
+./gradlew ktlintCheck detekt

CONTRIBUTING.md

@@ -81,8 +81,13 @@ We use the offical [style guide](https://kotlinlang.org/docs/reference/coding-co
 ./gradlew ktlintFormat
 ```
 
-Note: ktlint does not allow group imports using `.*`. You can configure IntelliJ to disallow this by going to preferences `Editor > Code Style > Kotlin > Imports` and select "Use single name imports".
+A pre-push git hook that automatically will perform these checks is available. You can configure it with the following command:
 
+```
+git config core.hooksPath .githooks
+```
+
+Note: ktlint does not allow group imports using `.*`. You can configure IntelliJ to disallow this by going to preferences `Editor > Code Style > Kotlin > Imports` and select "Use single name imports".
 
 ## Multiplatform source layout