Better error message for only readable/only writable properties in UnusedPrivatePropertyRule

Author: ondrejmirtes

src/Rules/DeadCode/UnusedPrivatePropertyRule.php

@@ -16,6 +16,7 @@
 use function array_map;
 use function count;
 use function is_string;
+use function lcfirst;
 use function sprintf;
 use function str_contains;
 
@@ -111,6 +112,8 @@ public function processNode(Node $node, Scope $scope): array
 				'read' => $read,
 				'written' => $written,
 				'node' => $property,
+				'onlyReadable' => $property->isReadable() && !$property->isWritable(),
+				'onlyWritable' => $property->isWritable() && !$property->isReadable(),
 			];
 		}
 
@@ -222,18 +225,32 @@ public function processNode(Node $node, Scope $scope): array
 						->identifier('property.unused')
 						->build();
 				} else {
-					$errors[] = RuleErrorBuilder::message(sprintf('%s is never read, only written.', $propertyName))
+					if ($data['onlyReadable']) {
+						$errors[] = RuleErrorBuilder::message(sprintf('Readable %s is never read.', lcfirst($propertyName)))
+							->line($propertyNode->getStartLine())
+							->identifier('property.neverRead')
+							->build();
+					} else {
+						$errors[] = RuleErrorBuilder::message(sprintf('%s is never read, only written.', $propertyName))
+							->line($propertyNode->getStartLine())
+							->identifier('property.onlyWritten')
+							->tip($tip)
+							->build();
+					}
+				}
+			} elseif (!$data['written'] && (!array_key_exists($name, $uninitializedProperties) || !$this->checkUninitializedProperties)) {
+				if ($data['onlyWritable']) {
+					$errors[] = RuleErrorBuilder::message(sprintf('Writable %s is never written.', lcfirst($propertyName)))
 						->line($propertyNode->getStartLine())
-						->identifier('property.onlyWritten')
+						->identifier('property.neverWritten')
+						->build();
+				} else {
+					$errors[] = RuleErrorBuilder::message(sprintf('%s is never written, only read.', $propertyName))
+						->line($propertyNode->getStartLine())
+						->identifier('property.onlyRead')
 						->tip($tip)
 						->build();
 				}
-			} elseif (!$data['written'] && (!array_key_exists($name, $uninitializedProperties) || !$this->checkUninitializedProperties)) {
-				$errors[] = RuleErrorBuilder::message(sprintf('%s is never written, only read.', $propertyName))
-					->line($propertyNode->getStartLine())
-					->identifier('property.onlyRead')
-					->tip($tip)
-					->build();
 			}
 		}
 

tests/PHPStan/Rules/DeadCode/UnusedPrivatePropertyRuleTest.php

@@ -408,7 +408,16 @@ public function testBug12702(): void
 		$this->alwaysWrittenTags = [];
 		$this->alwaysReadTags = [];
 
-		$this->analyse([__DIR__ . '/data/bug-12702.php'], []);
+		$this->analyse([__DIR__ . '/data/bug-12702.php'], [
+			[
+				'Readable property Bug12702\Foo2::$i is never read.',
+				43,
+			],
+			[
+				'Writable property Bug12702\Bar2::$i is never written.',
+				54,
+			],
+		]);
 	}
 
 }

tests/PHPStan/Rules/DeadCode/data/bug-12702.php

@@ -33,3 +33,29 @@ public function x(): void {
 		$this->i = 'foo';
 	}
 }
+
+class Foo2
+{
+	/**
+	 * @var string[]
+	 */
+	public array $x = [];
+	private ?string $i { get => $this->x[$this->k] ?? null; }
+	private int $k = 0;
+
+}
+
+class Bar2
+{
+	/**
+	 * @var string[]
+	 */
+	public array $x = [];
+	private ?string $i {
+		set {
+			$this->x[$this->k] = $value;
+		}
+	}
+	private int $k = 0;
+
+}