Support PHP 8.1 (#23)

.github/workflows/test.yml

@@ -24,6 +24,12 @@ jobs:
           - '7.3'
           - '7.4'
           - '8.0'
+          - '8.1'
+        exclude:
+            # PHPUnit prefer-lowest on 8.1 fails because the 8.x line doesn't
+            # specifiy compatibility correctly. Doubt that'll get fixed.
+            - php: '8.1'
+              dependencies: low
 
     steps:
       - name: Check out code

phpunit.xml

@@ -6,6 +6,10 @@
          beStrictAboutCoversAnnotation="false"
          beStrictAboutOutputDuringTests="true"
          beStrictAboutTodoAnnotatedTests="true"
+         convertDeprecationsToExceptions="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
          verbose="true">
     <testsuite name="default">
         <directory suffix="Test.php">tests</directory>

src/Containers/ParsedInput.php

@@ -150,8 +150,10 @@ public function asArray(): array
 
     /**
      * Invoked via `isset` and `empty`
+     *
+     * @return never
      */
-    public function offsetExists($offset)
+    public function offsetExists($offset): bool
     {
         throw new BadMethodCallException(
             "ParsedInput is already validated, and contains all expected " .
@@ -161,8 +163,10 @@ public function offsetExists($offset)
 
     /**
      * Invoked by array access of the object
+     *
      * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         $data = $this->getData();
@@ -181,16 +185,20 @@ public function offsetGet($offset)
 
     /**
      * Invoked by setting an array value on the object
+     *
+     * @return never
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value): void
     {
         throw new BadMethodCallException("ParsedInput is read-only");
     }
 
     /**
      * Invoked via `unset`
+     *
+     * @return never
      */
-    public function offsetUnset($offset)
+    public function offsetUnset($offset): void
     {
         throw new BadMethodCallException("ParsedInput is read-only");
     }