From 708bb4e581d415c9f0924f150d03fd6ecdeb1c81 Mon Sep 17 00:00:00 2001
From: James Buncle <jbuncle@hotmail.com>
Date: Wed, 1 Apr 2026 20:50:59 +0100
Subject: [PATCH] Add ordering false-positive regressions

---
 src/Signature/ContractIdentity.php | 20 +++++--
 src/Signature/TraitUseIdentity.php | 25 +++++++--
 tests/run.php                      | 86 ++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+), 6 deletions(-)

diff --git a/src/Signature/ContractIdentity.php b/src/Signature/ContractIdentity.php
index c53fed9..813f796 100644
--- a/src/Signature/ContractIdentity.php
+++ b/src/Signature/ContractIdentity.php
@@ -32,7 +32,7 @@ public function toIdentityKey(): string {
             'kind:' . $this->kind,
             'types:[' . implode(',', array_map(function (IdentityKey $type): string {
                 return $type->toIdentityKey();
-            }, $this->types)) . ']',
+            }, $this->getNormalisedTypes())) . ']',
         ]);
     }
 
@@ -41,12 +41,26 @@ public function equals(IdentityKey $other): bool {
             return false;
         }
 
-        foreach ($this->types as $index => $type) {
-            if (!$type->equals($other->types[$index])) {
+        $left = $this->getNormalisedTypes();
+        $right = $other->getNormalisedTypes();
+        foreach ($left as $index => $type) {
+            if (!$type->equals($right[$index])) {
                 return false;
             }
         }
 
         return true;
     }
+
+    /**
+     * @return IdentityKey[]
+     */
+    private function getNormalisedTypes(): array {
+        $types = $this->types;
+        usort($types, function (IdentityKey $left, IdentityKey $right): int {
+            return strcmp($left->toIdentityKey(), $right->toIdentityKey());
+        });
+
+        return $types;
+    }
 }
diff --git a/src/Signature/TraitUseIdentity.php b/src/Signature/TraitUseIdentity.php
index e714543..667dbfe 100644
--- a/src/Signature/TraitUseIdentity.php
+++ b/src/Signature/TraitUseIdentity.php
@@ -50,7 +50,7 @@ public function toIdentityKey(): string {
             'kind:' . $this->kind,
             'traits:[' . implode(',', array_map(function (IdentityKey $trait): string {
                 return $trait->toIdentityKey();
-            }, $this->traits)) . ']',
+            }, $this->getNormalisedTraits())) . ']',
             'method:' . ($this->method ?? ''),
             'newName:' . ($this->newName ?? ''),
             'newModifier:' . ($this->newModifier ?? ''),
@@ -67,12 +67,31 @@ public function equals(IdentityKey $other): bool {
             return false;
         }
 
-        foreach ($this->traits as $index => $trait) {
-            if (!$trait->equals($other->traits[$index])) {
+        $left = $this->getNormalisedTraits();
+        $right = $other->getNormalisedTraits();
+        foreach ($left as $index => $trait) {
+            if (!$trait->equals($right[$index])) {
                 return false;
             }
         }
 
         return true;
     }
+
+    /**
+     * @return IdentityKey[]
+     */
+    private function getNormalisedTraits(): array {
+        if ($this->kind !== 'precedence' || count($this->traits) <= 2) {
+            return $this->traits;
+        }
+
+        $selected = $this->traits[0];
+        $insteadOfTraits = array_slice($this->traits, 1);
+        usort($insteadOfTraits, function (IdentityKey $left, IdentityKey $right): int {
+            return strcmp($left->toIdentityKey(), $right->toIdentityKey());
+        });
+
+        return array_merge([$selected], $insteadOfTraits);
+    }
 }
diff --git a/tests/run.php b/tests/run.php
index 3182996..b84d699 100644
--- a/tests/run.php
+++ b/tests/run.php
@@ -787,6 +787,89 @@ function testNamespaceConstantOrderingDoesNotBumpVersion(): void {
     assertSameValue('Reordering namespace constants without changing values should remain PATCH.', 'PATCH', $diff->diff('HEAD', 'WC')->getIncrement());
 }
 
+
+function testImplementedContractOrderingDoesNotBumpVersion(): void {
+    $root = createRepository('implements-ordering', [
+        'src/Worker.php' => <<<'PHP'
+<?php
+namespace Demo;
+use Vendor\Contract\FirstContract;
+use Vendor\Contract\SecondContract;
+class Worker implements FirstContract, SecondContract {}
+PHP,
+    ]);
+
+    writeFile($root . '/src/Worker.php', <<<'PHP'
+<?php
+namespace Demo;
+use Vendor\Contract\FirstContract;
+use Vendor\Contract\SecondContract;
+class Worker implements SecondContract, FirstContract {}
+PHP
+    );
+
+    $diff = new SemVerDiff($root, [], []);
+    assertSameValue('Reordering implemented contracts without changing the set should remain PATCH.', 'PATCH', $diff->diff('HEAD', 'WC')->getIncrement());
+}
+
+function testExtendedInterfaceOrderingDoesNotBumpVersion(): void {
+    $root = createRepository('interface-extends-ordering', [
+        'src/Contract.php' => <<<'PHP'
+<?php
+namespace Demo;
+use Vendor\Contract\FirstBase;
+use Vendor\Contract\SecondBase;
+interface Contract extends FirstBase, SecondBase {}
+PHP,
+    ]);
+
+    writeFile($root . '/src/Contract.php', <<<'PHP'
+<?php
+namespace Demo;
+use Vendor\Contract\FirstBase;
+use Vendor\Contract\SecondBase;
+interface Contract extends SecondBase, FirstBase {}
+PHP
+    );
+
+    $diff = new SemVerDiff($root, [], []);
+    assertSameValue('Reordering extended interfaces without changing the set should remain PATCH.', 'PATCH', $diff->diff('HEAD', 'WC')->getIncrement());
+}
+
+function testTraitPrecedenceOrderingDoesNotBumpVersion(): void {
+    $root = createRepository('trait-precedence-ordering', [
+        'src/Worker.php' => <<<'PHP'
+<?php
+namespace Demo;
+trait SharedTrait { public function boot() {} }
+trait FirstFallback { public function boot() {} }
+trait SecondFallback { public function boot() {} }
+class Worker {
+    use SharedTrait, FirstFallback, SecondFallback {
+        SharedTrait::boot insteadof FirstFallback, SecondFallback;
+    }
+}
+PHP,
+    ]);
+
+    writeFile($root . '/src/Worker.php', <<<'PHP'
+<?php
+namespace Demo;
+trait SharedTrait { public function boot() {} }
+trait FirstFallback { public function boot() {} }
+trait SecondFallback { public function boot() {} }
+class Worker {
+    use SharedTrait, FirstFallback, SecondFallback {
+        SharedTrait::boot insteadof SecondFallback, FirstFallback;
+    }
+}
+PHP
+    );
+
+    $diff = new SemVerDiff($root, [], []);
+    assertSameValue('Reordering insteadof fallback traits without changing the set should remain PATCH.', 'PATCH', $diff->diff('HEAD', 'WC')->getIncrement());
+}
+
 function testIncludePathsRestrictTheSurface(): void {
     $root = createRepository('include-paths', [
         'src/Foo.php' => "<?php\nnamespace Demo;\nclass Foo { public function stableMethod() {} }\n",
@@ -2209,6 +2292,9 @@ function testCliParsingAndDefaults(): void {
 testGroupedAndUngroupedConstImportsRemainEquivalent();
 testTraitAliasFormattingEquivalenceIsPatch();
 testNamespaceConstantOrderingDoesNotBumpVersion();
+testImplementedContractOrderingDoesNotBumpVersion();
+testExtendedInterfaceOrderingDoesNotBumpVersion();
+testTraitPrecedenceOrderingDoesNotBumpVersion();
 testGitIgnoreInlineCommentsAreIgnored();
 testRootAnchoredGitIgnorePatternsAreHonoured();
 testIncludePathsRestrictTheSurface();