Fix: Temporal diff() incorrectly compares cast values as strings

src/Phaseolies/Database/Temporal/InteractsWithTemporal.php

@@ -129,7 +129,7 @@ public function diff(string $from, string $to): ?array
         foreach ($snapshotTo as $col => $newVal) {
             if (!array_key_exists($col, $snapshotFrom)) {
                 $added[$col] = $newVal;
-            } elseif ((string) $snapshotFrom[$col] !== (string) $newVal) {
+            } elseif (self::snapshotValuesDiffer($snapshotFrom[$col], $newVal)) {
                 $changes[$col] = ['from' => $snapshotFrom[$col], 'to' => $newVal];
             }
         }
@@ -259,6 +259,49 @@ private function snapshotAt(string $datetime): ?array
         return json_decode($row['snapshot'], true) ?? null;
     }
 
+    /**
+     * Determine whether two snapshot values are different
+     *
+     * @param mixed $from
+     * @param mixed $to
+     * @return bool
+     */
+    private static function snapshotValuesDiffer(mixed $from, mixed $to): bool
+    {
+        if (is_array($from) || is_array($to)) {
+            if (!is_array($from) || !is_array($to) || count($from) !== count($to)) {
+                return true;
+            }
+
+            foreach ($from as $key => $value) {
+                if (!array_key_exists($key, $to) || self::snapshotValuesDiffer($value, $to[$key])) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        if ($from === null || $to === null) {
+            return $from !== $to;
+        }
+
+        if (is_object($from) || is_object($to)) {
+            return $from != $to;
+        }
+
+        return self::snapshotScalar($from) !== self::snapshotScalar($to);
+    }
+
+    /**
+     * @param bool|int|float|string $value
+     * @return string
+     */
+    private static function snapshotScalar(mixed $value): string
+    {
+        return is_bool($value) ? ($value ? '1' : '0') : (string) $value;
+    }
+
     /**
      * Assert that the model is temporal and has a primary key loaded.
      *

tests/Model/TemporalModelTest.php

@@ -505,6 +505,106 @@ private function registerTemporalHooks(string $class): void
         $register();
     }
 
+    public function testDiffDetectsChangesInArrayValues(): void
+    {
+        $changes = $this->diffBetween(['tags' => ['a']], ['tags' => ['b']]);
+
+        $this->assertSame(['tags'], array_keys($changes));
+        $this->assertSame(['a'], $changes['tags']['from']);
+        $this->assertSame(['b'], $changes['tags']['to']);
+    }
+
+    public function testDiffDetectsAddedAndRemovedArrayItemsAndNestedChanges(): void
+    {
+        $this->assertArrayHasKey('t', $this->diffBetween(['t' => ['a']], ['t' => ['a', 'b']]));
+        $this->assertArrayHasKey('t', $this->diffBetween(['t' => ['a', 'b']], ['t' => ['a']]));
+        $this->assertArrayHasKey('t', $this->diffBetween(['t' => ['k' => ['x' => 1]]], ['t' => ['k' => ['x' => 2]]]));
+        $this->assertArrayHasKey('t', $this->diffBetween(['t' => []], ['t' => ['a']]));
+        $this->assertArrayHasKey('t', $this->diffBetween(['t' => ['a']], ['t' => 'a']));
+    }
+
+    public function testDiffIgnoresEqualArraysWithoutWarnings(): void
+    {
+        $warnings = [];
+        set_error_handler(function (int $no, string $message) use (&$warnings) {
+            $warnings[] = $message;
+
+            return true;
+        });
+
+        try {
+            $changes = $this->diffBetween(
+                ['t' => ['a', 'b'], 'o' => ['x' => 1, 'y' => ['z' => true]]],
+                ['t' => ['a', 'b'], 'o' => ['y' => ['z' => true], 'x' => 1]]
+            );
+        } finally {
+            restore_error_handler();
+        }
+
+        $this->assertSame([], $changes);
+        $this->assertSame([], $warnings);
+    }
+
+    public function testDiffKeepsNullFalseAndEmptyStringApart(): void
+    {
+        $this->assertArrayHasKey('v', $this->diffBetween(['v' => null], ['v' => '']));
+        $this->assertArrayHasKey('v', $this->diffBetween(['v' => false], ['v' => null]));
+        $this->assertArrayHasKey('v', $this->diffBetween(['v' => false], ['v' => '']));
+        $this->assertArrayHasKey('v', $this->diffBetween(['v' => null], ['v' => 0]));
+        $this->assertArrayHasKey('v', $this->diffBetween(['v' => true], ['v' => false]));
+        $this->assertSame([], $this->diffBetween(['v' => null], ['v' => null]));
+    }
+
+    public function testDiffTreatsDatabaseStyleScalarsAsEqual(): void
+    {
+        $this->assertSame([], $this->diffBetween(['n' => 1], ['n' => '1']));
+        $this->assertSame([], $this->diffBetween(['n' => true], ['n' => 1]));
+        $this->assertSame([], $this->diffBetween(['n' => false], ['n' => '0']));
+        $this->assertSame([], $this->diffBetween(['n' => 1.0], ['n' => 1]));
+        $this->assertArrayHasKey('n', $this->diffBetween(['n' => 1], ['n' => 2]));
+    }
+
+    public function testDiffStillReportsAddedAndRemovedColumns(): void
+    {
+        $diff = $this->diffReport(['a' => 1], ['a' => 1, 'b' => ['x']]);
+
+        $this->assertSame(['b' => ['x']], $diff['added']);
+        $this->assertSame([], $diff['removed']);
+
+        $diff = $this->diffReport(['a' => 1, 'b' => 2], ['a' => 1]);
+
+        $this->assertSame(['b' => 2], $diff['removed']);
+    }
+
+    private function diffBetween(array $from, array $to): array
+    {
+        return $this->diffReport($from, $to)['changes'];
+    }
+
+    /**
+     * Store two hand-written snapshots for one record and diff them.
+     */
+    private function diffReport(array $from, array $to): array
+    {
+        $this->travelTo('2026-02-01 10:00:00.100000');
+        $created = MockTemporalRecord::create(['title' => 'T', 'status' => 'a', 'body' => 'b']);
+        $record = MockTemporalRecord::find($created->id);
+
+        $history = $record->historyTable();
+        $this->pdo->exec("DELETE FROM {$history}");
+
+        foreach ([[$from, '2026-02-01 10:00:00.000000'], [$to, '2026-02-01 11:00:00.000000']] as [$snapshot, $at]) {
+            $this->pdo
+                ->prepare("INSERT INTO {$history} (record_id, action, valid_from, snapshot) VALUES (?, 'updated', ?, ?)")
+                ->execute([$record->id, $at, json_encode($snapshot)]);
+        }
+
+        $report = $record->diff('2026-02-01 10:30:00', '2026-02-01 12:00:00');
+        $this->pdo->exec('DELETE FROM temporal_records');
+
+        return $report;
+    }
+
     private function travelTo(string $datetime): void
     {
         Carbon::setTestNow(Carbon::parse($datetime, 'UTC'));