Setup static analysis

I select levels that do not involve any code change.

.github/workflows/static-analysis.yml

@@ -0,0 +1,28 @@
+name: "Static Analysis"
+
+on:
+  pull_request:
+    branches:
+      - "master"
+    paths:
+      - .github/workflows/static-analysis.yml
+      - composer.*
+      - lib/**
+      - phpstan*
+      - psalm*
+      - tests
+  push:
+    branches:
+      - "master"
+    paths:
+      - .github/workflows/static-analysis.yml
+      - composer.*
+      - lib/**
+      - phpstan*
+      - psalm*
+      - tests
+
+jobs:
+  static-analysis:
+    name: "Static Analysis"
+    uses: "doctrine/.github/.github/workflows/[email protected]"

composer.json

@@ -8,9 +8,11 @@
         "php": "^7.1|^8.0"
     },
     "require-dev": {
+        "doctrine/coding-standard": "^9",
         "phpunit/phpunit": "^7.5|^8.5|^9.5",
+        "phpstan/phpstan": "1.4.10 || 1.10.15",
         "psr/log": "^1|^2|^3",
-        "doctrine/coding-standard": "^9"
+        "vimeo/psalm": "4.30.0 || 5.12.0"
     },
     "suggest": {
         "psr/log": "Allows logging deprecations via PSR-3 logger implementation"

phpstan.neon

@@ -0,0 +1,5 @@
+parameters:
+	level: 3
+	paths:
+		- lib
+		- tests

psalm.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<psalm
+    errorLevel="4"
+    resolveFromConfigFile="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+    findUnusedBaselineEntry="true"
+    findUnusedCode="false"
+>
+    <projectFiles>
+        <directory name="lib/Doctrine/Deprecations" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+</psalm>