Figure out get_taxonomies's return type

Author: szepeviktor

extension.neon

@@ -23,6 +23,10 @@ services:
         class: PHPStan\WordPress\GetPostsDynamicFunctionReturnTypeExtension
         tags:
             - phpstan.broker.dynamicFunctionReturnTypeExtension
+    -
+        class: PHPStan\WordPress\GetTaxonomiesDynamicFunctionReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicFunctionReturnTypeExtension
 parameters:
     bootstrapFiles:
         - ../../php-stubs/wordpress-stubs/wordpress-stubs.php

src/GetTaxonomiesDynamicFunctionReturnTypeExtension.php

@@ -0,0 +1,59 @@
+<?php
+
+/**
+ * Set return type of get_post().
+ */
+
+declare(strict_types=1);
+
+namespace PHPStan\WordPress;
+
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\Type;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\IntegerType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Constant\ConstantStringType;
+
+class GetTaxonomiesDynamicFunctionReturnTypeExtension implements \PHPStan\Type\DynamicFunctionReturnTypeExtension
+{
+    public function isFunctionSupported(FunctionReflection $functionReflection): bool
+    {
+        return in_array($functionReflection->getName(), ['get_taxonomies'], true);
+    }
+
+    /**
+     * @see https://developer.wordpress.org/reference/functions/get_taxonomies/
+     */
+    public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): Type
+    {
+        // Called without second $output arguments
+        if (count($functionCall->args) <= 1) {
+            return new ArrayType(new IntegerType(), new ObjectType('WP_Taxonomy'));
+        }
+
+        $argumentType = $scope->getType($functionCall->args[1]->value);
+
+        // When called with a non-string $output, return default return type
+        if (! $argumentType instanceof ConstantStringType) {
+            return ParametersAcceptorSelector::selectFromArgs(
+                $scope,
+                $functionCall->args,
+                $functionReflection->getVariants()
+            )->getReturnType();
+        }
+
+        // Called with a string $output
+        switch ($argumentType->getValue()) {
+            case 'names':
+                return new ArrayType(new IntegerType(), new StringType());
+            case 'objects':
+            default:
+                return new ArrayType(new IntegerType(), new ObjectType('WP_Taxonomy'));
+        }
+    }
+}