PHPStan integration

.travis.yml

@@ -28,7 +28,9 @@ install:
   - if [[ $setup = 'stable' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-stable; fi
   - if [[ $setup = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-stable --prefer-lowest; fi
 
-script: vendor/bin/phpunit --verbose --coverage-text --coverage-clover=coverage.xml
+script:
+  - vendor/bin/phpunit --verbose --coverage-text --coverage-clover=coverage.xml
+  - if [[ $PHPSTAN = 1 ]]; then composer require --dev phpstan/phpstan:^0.5.2 && vendor/bin/phpstan analyse -c phpstan.neon -l 3 src tests; fi
 
 after_success:
   - if [[ $coverage = 'true' ]]; then bash <(curl -s https://codecov.io/bash); fi
@@ -55,10 +57,14 @@ matrix:
       env: setup=lowest
     - php: 7.0
       env: setup=stable
+    - php: 7.0
+      env: PHPSTAN=1
     - php: 7.1
       env: setup=lowest
     - php: 7.1
       env: setup=stable
+    - php: 7.1
+      env: PHPSTAN=1
   allow_failures:
     - php: hhvm
   fast_finish: true

phpstan.neon

@@ -0,0 +1,7 @@
+parameters:
+	ignoreErrors:
+		- '#Access to an undefined property#'
+		- '#Call to an undefined static method#'
+		- '#Property Carbon\\Carbon::\$timezone \(DateTimeZone\) does not accept string#'
+		- '#Property Carbon\\Carbon::\$tz \(DateTimeZone\) does not accept string#'
+		- '#Method Carbon\\Carbon::instance\(\) should return static\(Carbon\\Carbon\) but returns DateTime#'