run PHPStan on Travis

.gitignore

@@ -1,3 +1,4 @@
 /composer.lock
+/phpstan.neon
 /phpunit.xml
 /vendor

.travis.yml

@@ -14,7 +14,7 @@ matrix:
     - php: 7.0
       env: DEPS='lowest'
     - php: 7.3
-      env: DEPS='unmodified'
+      env: DEPS='unmodified' WITH_STATIC_ANALYSIS='yes'
     - php: 7.3
       env: SYMFONY_VERSION='3.4.*' PARAM_DB_DRIVER='pdo_sqlite' SYMFONY_DEPRECATIONS_HELPER='9'
     - php: 7.3
@@ -46,7 +46,9 @@ before_script:
 
 script:
   # validate composer.json
-  - composer validate --strict --no-check-lock
+  - if [ -n "${WITH_STATIC_ANALYSIS:-}" ]; then composer validate --strict --no-check-lock; fi;
+  # run PHPStan
+  - if [ -n "${WITH_STATIC_ANALYSIS:-}" ]; then vendor/bin/phpstan analyse; fi;
   # run PHPUnit
   - phpdbg -qrr vendor/phpunit/phpunit/phpunit -v --coverage-clover build/logs/clover.xml
   # upload code coverage data

.travis_install_dependencies.sh

@@ -22,4 +22,8 @@ case "${DEPS:-}" in
 		fi
 esac
 
+if [ -n "${WITH_STATIC_ANALYSIS:-}" ]; then
+	composer require --no-update --dev phpstan/phpstan-shim
+fi
+
 composer update ${COMPOSER_UPDATE_ARGS:-}

phpstan.neon.dist

@@ -0,0 +1,24 @@
+parameters:
+	level: 5
+	paths:
+		- %currentWorkingDirectory%
+	excludes_analyse:
+		- %currentWorkingDirectory%/Tests/*
+		- %currentWorkingDirectory%/vendor/*
+	ignoreErrors:
+		-
+			message: '#^Result of || is always true\.$#'
+			path: %currentWorkingDirectory%/Form/Step.php
+		# TODO remove as soon as Symfony >= 4.1 is required
+		-
+			message: '#^Call to function property_exists\(\) with .+ and .size. will always evaluate to false\.$#'
+			path: %currentWorkingDirectory%/Storage/SerializableFile.php
+		# TODO remove as soon as Symfony >= 4.1 is required
+		- '#^Parameter \#5 \$test of class Symfony\\Component\\HttpFoundation\\File\\UploadedFile constructor expects bool, null given\.$#'
+		# TODO remove as soon as Symfony >= 4.3 is required
+		-
+			message: '#^Method Symfony\\Contracts\\EventDispatcher\\EventDispatcherInterface::dispatch\(\) invoked with 2 parameters, 1 required\.$#'
+			path: %currentWorkingDirectory%/Form/FormFlow.php
+		-
+			message: '#^Parameter \#1 \$event of method Symfony\\Contracts\\EventDispatcher\\EventDispatcherInterface::dispatch\(\) expects object, string given\.$#'
+			path: %currentWorkingDirectory%/Form/FormFlow.php