Gracefully handle non-contiguous arrays in Differ

Fixes #909.
nikic · May 21, 2023 · 289756d · 289756d
1 parent 8490c0e
commit 289756d
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Showing 3 changed files with 26 additions and 1 deletion.
diff --git a/lib/PhpParser/Internal/Differ.php b/lib/PhpParser/Internal/Differ.php
@@ -33,6 +33,8 @@ public function __construct(callable $isEqual) {
      * @return DiffElem[] Diff (edit script)
      */
     public function diff(array $old, array $new): array {
+        $old = \array_values($old);
+        $new = \array_values($new);
         list($trace, $x, $y) = $this->calculateTrace($old, $new);
         return $this->extractDiff($trace, $x, $y, $old, $new);
     }

diff --git a/test/PhpParser/Internal/DifferTest.php b/test/PhpParser/Internal/DifferTest.php
@@ -65,4 +65,15 @@ public function provideTestDiffWithReplacements() {
             ['abcde', 'axyzue', 'a-b-c-d+x+y+z+ue'],
         ];
     }
+
+    public function testNonContiguousIndices() {
+        $differ = new Differ(function ($a, $b) {
+            return $a === $b;
+        });
+        $diff = $differ->diff([0 => 'a', 2 => 'b'], [0 => 'a', 3 => 'b']);
+        $this->assertEquals([
+            new DiffElem(DiffElem::TYPE_KEEP, 'a', 'a'),
+            new DiffElem(DiffElem::TYPE_KEEP, 'b', 'b'),
+        ], $diff);
+    }
 }
diff --git a/test/code/formatPreservation/listRemoval.test b/test/code/formatPreservation/listRemoval.test
@@ -207,4 +207,16 @@ class Foo
     function getBaz()
     {
     }
-}
+}
+-----
+<?php
+class Test {
+    use A, B;
+}
+-----
+unset($stmts[0]->stmts[0]->traits[0]);
+-----
+<?php
+class Test {
+    use B;
+}