Add static analysis

.circleci/config.yml

@@ -20,6 +20,9 @@ commands:
           key: composer-v1-{{ .Environment.CIRCLE_JOB }}-{{ checksum "composer.json" }}
           paths:
             - vendor
+  run-static-analysis:
+    steps:
+      - run: composer static-analysis
   run-unit-tests:
     steps:
       - run: composer test-unit-ci
@@ -37,6 +40,7 @@ jobs:
       - image: circleci/php:7.3
     steps:
       - prepare
+      - run-static-analysis
       - run-unit-tests
       - run:
           command: bash <(curl -s https://codecov.io/bash)
@@ -46,6 +50,7 @@ jobs:
       - image: circleci/php:7.4
     steps:
       - prepare
+      - run-static-analysis
       - run-unit-tests
       - run:
           command: bash <(curl -s https://codecov.io/bash)
@@ -55,6 +60,7 @@ jobs:
       - image: circleci/php:8.0
     steps:
       - prepare
+      - run-static-analysis
       - run-unit-tests
       - run:
           command: bash <(curl -s https://codecov.io/bash)

CONTRIBUTING.md

@@ -15,6 +15,12 @@ echo '#!/bin/sh' > .git/hooks/pre-commit && echo 'composer pre-commit' >> .git/h
 - Run `composer phpcs` for the changed PHP files before submitting your PR for review (optional). 
 - Keep PRs focused and change the minimum number of lines to achieve your goal.
 
+### Running static analysis
+
+Prior to making a PR, make sure the static analysis suite detects no defects:
+
+`composer static-analysis`
+
 ### Running unit tests
 
 Prior to making a PR, ensure that the unit tests pass:

composer.json

@@ -32,7 +32,8 @@
     "dealerdirect/phpcodesniffer-composer-installer": "^0.7",
     "cache/adapter-common": "^1.2",
     "cache/hierarchical-cache": "^1.1",
-    "cache/array-adapter": "^1.1"
+    "cache/array-adapter": "^1.1",
+    "phpstan/phpstan": "^0.12.64"
   },
   "autoload": {
     "psr-4": {
@@ -51,12 +52,14 @@
     "test-unit-ci": "SHELL_INTERACTIVE=1 \"vendor/bin/phpunit\" --stop-on-failure --coverage-clover=build/coverage.xml --testsuite=unit",
     "test-integration": "SHELL_INTERACTIVE=1 \"vendor/bin/phpunit\" --coverage-text --testsuite=integration",
     "test-integration-ci": "\"vendor/bin/phpunit\" --stop-on-failure --coverage-clover=build/coverage.xml --testsuite=integration",
+    "static-analysis": "@php ./vendor/bin/phpstan analyze",
     "compat": "@php ./vendor/bin/phpcs --standard=.phpcs-compat.xml.dist",
     "format": "@php ./vendor/bin/phpcbf",
     "lint": "@php ./vendor/bin/phpcs",
     "sniffs": "\"vendor/bin/phpcs\" -e",
     "config-phpcs": "Dealerdirect\\Composer\\Plugin\\Installers\\PHPCodeSniffer\\Plugin::run",
     "pre-commit": [
+      "@static-analysis",
       "@test",
       "@format",
       "@compat"

phpstan.neon

@@ -0,0 +1,5 @@
+parameters:
+    checkGenericClassInNonGenericObjectType: false
+    level: 1
+    paths:
+        - src