fix(SelectQuery): process the last partial chunk in runChunks() (#255)

Author: roxblnfk

src/Query/SelectQuery.php

@@ -305,7 +305,7 @@ public function runChunks(int $limit, callable $callback): void
         $select->limit($limit);
 
         $offset = 0;
-        while ($offset + $limit <= $count) {
+        while ($offset < $count) {
             $result = $callback(
                 $select->offset($offset)->getIterator(),
                 $offset,

tests/Database/Functional/Driver/Common/Driver/StatementTest.php

@@ -292,6 +292,90 @@ function ($result) use (&$count) {
         $this->assertSame(5, $count);
     }
 
+    public function testChunksProcessLastPartialChunk(): void
+    {
+        $table = $this->database->table('sample_table');
+        $this->fillData();
+
+        $select = $table->select()->orderBy('id');
+
+        // 10 rows split by chunks of 3: the last chunk holds the single remaining row (10 % 3 == 1)
+        $visited = [];
+        $select->runChunks(
+            3,
+            function (StatementInterface $result) use (&$visited): void {
+                foreach ($result as $row) {
+                    $visited[] = $row['id'];
+                }
+            },
+        );
+
+        $this->assertEquals(\range(1, 10), $visited);
+    }
+
+    public function testChunksWithLimitGreaterThanCount(): void
+    {
+        $table = $this->database->table('sample_table');
+        $this->fillData();
+
+        $select = $table->select()->orderBy('id');
+
+        // chunk size larger than the total row count must still yield every row in a single chunk
+        $visited = [];
+        $chunks = 0;
+        $select->runChunks(
+            100,
+            function (StatementInterface $result) use (&$visited, &$chunks): void {
+                $chunks++;
+                foreach ($result as $row) {
+                    $visited[] = $row['id'];
+                }
+            },
+        );
+
+        $this->assertSame(1, $chunks);
+        $this->assertEquals(\range(1, 10), $visited);
+    }
+
+    public function testChunksOnEmptyResultNeverInvokesCallback(): void
+    {
+        $table = $this->database->table('sample_table');
+        // no data inserted
+
+        $select = $table->select();
+
+        $invoked = false;
+        $select->runChunks(
+            5,
+            function () use (&$invoked): void {
+                $invoked = true;
+            },
+        );
+
+        $this->assertFalse($invoked);
+    }
+
+    public function testChunksPassOffsetAndCountToCallback(): void
+    {
+        $table = $this->database->table('sample_table');
+        $this->fillData();
+
+        $select = $table->select();
+
+        $offsets = [];
+        $counts = [];
+        $select->runChunks(
+            3,
+            function (StatementInterface $result, int $offset, int $count) use (&$offsets, &$counts): void {
+                $offsets[] = $offset;
+                $counts[] = $count;
+            },
+        );
+
+        $this->assertSame([0, 3, 6, 9], $offsets);
+        $this->assertSame([10, 10, 10, 10], $counts);
+    }
+
     public function testNativeParameters(): void
     {
         $this->fillData();