From 9664f7a9d2223c07e750f0dfc949c3accfa6b65e Mon Sep 17 00:00:00 2001
From: Ondrej Mirtes <ondrej@mirtes.cz>
Date: Fri, 8 Dec 2023 12:32:55 +0100
Subject: [PATCH] Bleeding edge - report unused result of ternary

---
 src/Rules/DeadCode/NoopRule.php               | 17 +++++++++++++++++
 tests/PHPStan/Rules/DeadCode/NoopRuleTest.php |  8 ++++++++
 tests/PHPStan/Rules/DeadCode/data/noop.php    |  6 ++++++
 3 files changed, 31 insertions(+)

diff --git a/src/Rules/DeadCode/NoopRule.php b/src/Rules/DeadCode/NoopRule.php
index d33e767ee3..38c8efb6b9 100644
--- a/src/Rules/DeadCode/NoopRule.php
+++ b/src/Rules/DeadCode/NoopRule.php
@@ -60,6 +60,23 @@ public function processNode(Node $node, Scope $scope): array
 						->build(),
 				];
 			}
+
+			if ($expr instanceof Node\Expr\Ternary) {
+				$if = $expr->if;
+				if ($if === null) {
+					$if = $expr->cond;
+				}
+
+				if (!$this->isNoopExpr($if) || !$this->isNoopExpr($expr->else)) {
+					return [];
+				}
+
+				return [
+					RuleErrorBuilder::message('Unused result of ternary operator.')
+						->line($expr->getLine())
+						->build(),
+				];
+			}
 		}
 		if (!$this->isNoopExpr($expr)) {
 			return [];
diff --git a/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php b/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php
index 50e52a4153..d28e07dccf 100644
--- a/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php
+++ b/tests/PHPStan/Rules/DeadCode/NoopRuleTest.php
@@ -92,6 +92,14 @@ public function testRule(): void
 				38,
 				'This operator has unexpected precedence, try disambiguating the logic with parentheses ().',
 			],
+			[
+				'Unused result of ternary operator.',
+				40,
+			],
+			[
+				'Unused result of ternary operator.',
+				41,
+			],
 		]);
 	}
 
diff --git a/tests/PHPStan/Rules/DeadCode/data/noop.php b/tests/PHPStan/Rules/DeadCode/data/noop.php
index b268cd19a8..927fe41143 100644
--- a/tests/PHPStan/Rules/DeadCode/data/noop.php
+++ b/tests/PHPStan/Rules/DeadCode/data/noop.php
@@ -36,4 +36,10 @@ function (stdClass $foo, bool $a, bool $b) {
 
 	$s = $a or doFoo();
 	$t = $a or $b;
+
+	$a ? $b : $s;
+	$a ?: $b;
+	$a ? doFoo() : $s;
+	$a ? $b : doFoo();
+	$a ? doFoo() : doBar();
 };