tests: configure PHPStan

Author: justlevine

.editorconfig

@@ -13,7 +13,7 @@ insert_final_newline = true
 trim_trailing_whitespace = true
 indent_style = tab
 
-[*.yml]
+[{*.yml,*.neon,*.neon.dist}]
 indent_style = space
 indent_size = 2
 

.gitignore

@@ -22,6 +22,7 @@ wp-tests-config.php
 /build
 /tests/phpunit/build
 /wp-cli.local.yml
+/phpstan.neon
 /jsdoc
 /composer.lock
 /vendor

composer.json

@@ -20,6 +20,7 @@
 		"squizlabs/php_codesniffer": "3.10.3",
 		"wp-coding-standards/wpcs": "~3.1.0",
 		"phpcompatibility/phpcompatibility-wp": "~2.1.3",
+		"phpstan/phpstan": "1.12.7",
 		"yoast/phpunit-polyfills": "^1.1.0"
 	},
 	"config": {
@@ -29,6 +30,7 @@
 		"lock": false
 	},
 	"scripts": {
+		"analyse": "@php ./vendor/bin/phpstan analyse -v",
 		"compat": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcs --standard=phpcompat.xml.dist --report=summary,source",
 		"format": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcbf --report=summary,source",
 		"lint": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcs --report=summary,source",

phpcs.xml.dist

@@ -81,6 +81,9 @@
 	<exclude-pattern>/tests/phpunit/build*</exclude-pattern>
 	<exclude-pattern>/tests/phpunit/data/*</exclude-pattern>
 
+	<!-- PHPStan bootstrap, stubs, and baseline. -->
+	<exclude-pattern>/tests/phpstan/*</exclude-pattern>
+
 	<exclude-pattern>/tools/*</exclude-pattern>
 
 	<!-- Drop-in plugins. -->

phpstan.neon.dist

@@ -0,0 +1,39 @@
+# PHPStan configuration for WordPress Core.
+#
+# To overload this configuration, copy this file to phpstan.neon and adjust as needed.
+#
+# https://phpstan.org/config-reference
+
+includes:
+  # The WordPress Core configuration file includes the base configuration for the WordPress codebase.
+  - tests/phpstan/base.neon
+  # The baseline file includes preexisting errors in the codebase that should be ignored.
+  # https://phpstan.org/user-guide/baseline
+  - tests/phpstan/baseline/level-0.php
+  - tests/phpstan/baseline/level-1.php
+  - tests/phpstan/baseline/level-2.php
+  - tests/phpstan/baseline/level-3.php
+  - tests/phpstan/baseline/level-4.php
+  - tests/phpstan/baseline/level-5.php
+  - tests/phpstan/baseline/level-6.php
+
+parameters:
+  level: 6
+
+  ignoreErrors:
+    # Inner functions aren't supported:
+    - '#Inner named functions are not supported by PHPStan#'
+    # Inner functions within the importer:
+    - '#Function wxr_[a-z_]+ not found#'
+
+    # Level 1:
+
+    # These are too noisy at the moment:
+    - '#Variable \$[a-zA-Z0-9_]+ might not be defined\.#'
+    - '#Variable \$[a-zA-Z0-9_]+ in isset\(\) always exists and is not nullable\.#'
+
+    # Level 6:
+
+    # WPCS syntax for iterable types is not supported:
+    -
+      identifier: missingType.iterableValue

tests/phpstan/base.neon

@@ -0,0 +1,66 @@
+# Base PHPStan configuration for WordPress Core.
+#
+# This is kept separate from the main PHPStan configuration file to allow for easy overloading while baseline errors are being fixed.
+#
+# https://phpstan.org/config-reference
+
+parameters:
+  # What directories and files should be scanned.
+  paths:
+    - ../../src
+  bootstrapFiles:
+    - bootstrap.php
+  scanFiles:
+    - ../../wp-config-sample.php
+    - ../../src/wp-admin/includes/ms.php
+  scanDirectories:
+    - ../../src/wp-includes
+    - ../../src/wp-admin
+  excludePaths:
+    analyseAndScan:
+      # These files are deprecated and should not be scanned.
+      - ../../src/wp-admin/includes/deprecated.php
+      - ../../src/wp-admin/includes/ms-deprecated.php
+      - ../../src/wp-admin/includes/noop.php
+      - ../../src/wp-includes/deprecated.php
+      - ../../src/wp-includes/ms-deprecated.php
+      - ../../src/wp-includes/pluggable-deprecated.php
+      # These files are not part of the WordPress Core codebase.
+      - ../../src/wp-content
+      # JavaScript/CSS/Asset files.
+      - ../../src/js
+      - ../../src/wp-admin/css
+      - ../../src/wp-admin/images
+      - ../../src/wp-admin/js
+    analyse:
+      # Third-party libraries.
+      - ../../src/wp-admin/includes/class-ftp-pure.php
+      - ../../src/wp-admin/includes/class-ftp-sockets.php
+      - ../../src/wp-admin/includes/class-ftp.php
+      - ../../src/wp-admin/includes/class-pclzip.php
+      - ../../src/wp-includes/atomlib.php
+      - ../../src/wp-includes/class-json.php
+      - ../../src/wp-includes/class-phpmailer.php
+      - ../../src/wp-includes/class-requests.php
+      - ../../src/wp-includes/class-simplepie.php
+      - ../../src/wp-includes/class-smtp.php
+      - ../../src/wp-includes/class-snoopy.php
+      - ../../src/wp-includes/class-wp-feed-cache.php
+      - ../../src/wp-includes/class-wp-http-ixr-client.php
+      - ../../src/wp-includes/class-wp-http-requests-hooks.php
+      - ../../src/wp-includes/class-wp-http-requests-response.php
+      - ../../src/wp-includes/class-wp-simplepie-file.php
+      - ../../src/wp-includes/class-wp-simplepie-sanitize-kses.php
+      - ../../src/wp-includes/class-wp-text-diff-renderer-inline.php
+      - ../../src/wp-includes/class-wp-text-diff-renderer-table.php
+      - ../../src/wp-includes/ID3
+      - ../../src/wp-includes/PHPMailer
+      - ../../src/wp-includes/pomo
+      - ../../src/wp-includes/random_compat
+      - ../../src/wp-includes/Requests
+      - ../../src/wp-includes/rss.php
+      - ../../src/wp-includes/SimplePie
+      - ../../src/wp-includes/sodium_compat
+      - ../../src/wp-includes/Text
+      # Contains errors that cannot be ignored by PHPStan.
+      - ../../src/wp-includes/html-api/class-wp-html-processor.php