Improve typing for Result interface

src/Cache/ArrayResult.php

@@ -17,7 +17,7 @@ final class ArrayResult implements Result
     private readonly int $columnCount;
     private int $num = 0;
 
-    /** @param list<array<string, mixed>> $data */
+    /** @param list<non-empty-array<string, mixed>> $data */
     public function __construct(private array $data)
     {
         $this->columnCount = $data === [] ? 0 : count($data[0]);
@@ -89,7 +89,7 @@ public function free(): void
         $this->data = [];
     }
 
-    /** @return array<string, mixed>|false */
+    /** @return non-empty-array<string,mixed>|false */
     private function fetch(): array|false
     {
         if (! isset($this->data[$this->num])) {

src/Connection.php

@@ -581,7 +581,7 @@ public function fetchAllNumeric(string $query, array $params = [], array $types
      * @param list<mixed>|array<string, mixed> $params
      * @psalm-param WrapperParameterTypeArray $types
      *
-     * @return list<array<string,mixed>>
+     * @return list<non-empty-array<string,mixed>>
      *
      * @throws Exception
      */

src/Driver/FetchUtils.php

@@ -4,6 +4,8 @@
 
 namespace Doctrine\DBAL\Driver;
 
+use function PHPStan\dumpType;
+
 /** @internal */
 final class FetchUtils
 {
@@ -20,7 +22,7 @@ public static function fetchOne(Result $result): mixed
     }
 
     /**
-     * @return list<list<mixed>>
+     * @return list<non-empty-list<mixed>>
      *
      * @throws Exception
      */
@@ -36,7 +38,7 @@ public static function fetchAllNumeric(Result $result): array
     }
 
     /**
-     * @return list<array<string,mixed>>
+     * @return list<non-empty-array<string,mixed>>
      *
      * @throws Exception
      */

src/Driver/IBMDB2/Result.php

@@ -28,6 +28,7 @@ public function __construct(private readonly mixed $statement)
 
     public function fetchNumeric(): array|false
     {
+        /** @var non-empty-list<mixed>|false $row */
         $row = @db2_fetch_array($this->statement);
 
         if ($row === false && db2_stmt_error($this->statement) !== '02000') {
@@ -39,6 +40,7 @@ public function fetchNumeric(): array|false
 
     public function fetchAssociative(): array|false
     {
+        /** @var non-empty-array<string,mixed>|false $row */
         $row = @db2_fetch_assoc($this->statement);
 
         if ($row === false && db2_stmt_error($this->statement) !== '02000') {

src/Driver/Mysqli/Result.php

@@ -14,6 +14,7 @@
 use function array_column;
 use function array_combine;
 use function array_fill;
+use function assert;
 use function count;
 
 final class Result implements ResultInterface
@@ -78,6 +79,11 @@ public function __construct(private readonly mysqli_stmt $statement)
         }
     }
 
+    /**
+     * @return non-empty-list<mixed>|false
+     *
+     * @throws StatementError
+     */
     public function fetchNumeric(): array|false
     {
         try {
@@ -100,6 +106,8 @@ public function fetchNumeric(): array|false
             $values[] = $v;
         }
 
+        assert([] !== $values);
+
         return $values;
     }
 
@@ -111,6 +119,8 @@ public function fetchAssociative(): array|false
             return false;
         }
 
+        assert($this->columnNames !== []);
+
         return array_combine($this->columnNames, $values);
     }
 

src/Driver/PgSQL/Result.php

@@ -22,6 +22,7 @@
 use function pg_field_type;
 use function pg_free_result;
 use function pg_num_fields;
+use function PHPStan\dumpType;
 use function substr;
 
 use const PGSQL_ASSOC;
@@ -53,6 +54,7 @@ public function fetchNumeric(): array|false
             return false;
         }
 
+        /** @var non-empty-list<mixed>|false $row */
         $row = pg_fetch_row($this->result);
         if ($row === false) {
             return false;
@@ -68,6 +70,7 @@ public function fetchAssociative(): array|false
             return false;
         }
 
+        /** @var non-empty-array<string,mixed>|false $row */
         $row = pg_fetch_assoc($this->result);
         if ($row === false) {
             return false;
@@ -93,7 +96,7 @@ public function fetchAllNumeric(): array
 
         return array_map(
             fn (array $row) => $this->mapNumericRow($row, $types),
-            pg_fetch_all($this->result, PGSQL_NUM),
+            $this->pgFetchAll($this->result, PGSQL_NUM),
         );
     }
 
@@ -108,7 +111,7 @@ public function fetchAllAssociative(): array
 
         return array_map(
             fn (array $row) => $this->mapAssociativeRow($row, $types),
-            pg_fetch_all($this->result, PGSQL_ASSOC),
+            $this->pgFetchAll($this->result, PGSQL_ASSOC),
         );
     }
 
@@ -184,10 +187,10 @@ private function fetchAssociativeColumnTypes(): array
     }
 
     /**
-     * @param list<string|null>  $row
+     * @param non-empty-list<string|null>  $row
      * @param array<int, string> $types
      *
-     * @return list<mixed>
+     * @return non-empty-list<mixed>
      */
     private function mapNumericRow(array $row, array $types): array
     {
@@ -201,10 +204,10 @@ private function mapNumericRow(array $row, array $types): array
     }
 
     /**
-     * @param array<string, string|null> $row
-     * @param array<string, string>      $types
+     * @param non-empty-array<string, string|null> $row
+     * @param array<string, string>                $types
      *
-     * @return array<string, mixed>
+     * @return non-empty-array<string, mixed>
      */
     private function mapAssociativeRow(array $row, array $types): array
     {
@@ -237,4 +240,15 @@ private function mapType(string $postgresType, ?string $value): string|int|float
             default => $value,
         };
     }
+
+    /**
+     * @return (
+     *     $mode is PGSQL_NUM ? array<non-empty-list<string|null>> : array<non-empty-array<string, mixed>>
+     * )
+     */
+    private function pgFetchAll(PgSqlResult $result, int $mode = PGSQL_ASSOC): array
+    {
+        /** @var array<non-empty-array<string, mixed>> */
+        return pg_fetch_all($result, $mode);
+    }
 }

src/Driver/SQLite3/Result.php

@@ -27,6 +27,7 @@ public function fetchNumeric(): array|false
             return false;
         }
 
+        /** @var non-empty-list<mixed>|false */
         return $this->result->fetchArray(SQLITE3_NUM);
     }
 
@@ -36,6 +37,7 @@ public function fetchAssociative(): array|false
             return false;
         }
 
+        /** @var non-empty-array<string,mixed>|false */
         return $this->result->fetchArray(SQLITE3_ASSOC);
     }
 

src/Portability/Converter.php

@@ -53,7 +53,7 @@ public function __construct(bool $convertEmptyStringToNull, bool $rightTrimStrin
     /**
      * @param array<int,mixed>|false $row
      *
-     * @return list<mixed>|false
+     * @return non-empty-list<mixed>|false
      */
     public function convertNumeric(array|false $row): array|false
     {
@@ -63,7 +63,7 @@ public function convertNumeric(array|false $row): array|false
     /**
      * @param array<string,mixed>|false $row
      *
-     * @return array<string,mixed>|false
+     * @return non-empty-array<string, mixed>|false
      */
     public function convertAssociative(array|false $row): array|false
     {
@@ -78,7 +78,7 @@ public function convertOne(mixed $value): mixed
     /**
      * @param list<list<mixed>> $data
      *
-     * @return list<list<mixed>>
+     * @return list<non-empty-list<mixed>>
      */
     public function convertAllNumeric(array $data): array
     {
@@ -88,7 +88,7 @@ public function convertAllNumeric(array $data): array
     /**
      * @param list<array<string,mixed>> $data
      *
-     * @return list<array<string,mixed>>
+     * @return list<non-empty-array<string,mixed>>
      */
     public function convertAllAssociative(array $data): array
     {

src/Result.php

@@ -23,7 +23,7 @@ public function __construct(private readonly DriverResult $result, private reado
     /**
      * Returns the next row of the result as a numeric array or FALSE if there are no more rows.
      *
-     * @return list<mixed>|false
+     * @return non-empty-list<mixed>|false
      *
      * @throws Exception
      */
@@ -39,7 +39,7 @@ public function fetchNumeric(): array|false
     /**
      * Returns the next row of the result as an associative array or FALSE if there are no more rows.
      *
-     * @return array<string,mixed>|false
+     * @return non-empty-array<string,mixed>|false
      *
      * @throws Exception
      */
@@ -69,7 +69,7 @@ public function fetchOne(): mixed
     /**
      * Returns an array containing all of the result rows represented as numeric arrays.
      *
-     * @return list<list<mixed>>
+     * @return list<non-empty-list<mixed>>
      *
      * @throws Exception
      */
@@ -85,7 +85,7 @@ public function fetchAllNumeric(): array
     /**
      * Returns an array containing all of the result rows represented as associative arrays.
      *
-     * @return list<array<string,mixed>>
+     * @return list<non-empty-array<string,mixed>>
      *
      * @throws Exception
      */

tests/Cache/ArrayStatementTest.php

@@ -11,7 +11,7 @@
 
 class ArrayStatementTest extends TestCase
 {
-    /** @var list<array<string, mixed>> */
+    /** @var list<non-empty-array<string, mixed>> */
     private array $users = [
         [
             'username' => 'jwage',

tests/Connection/CachedQueryTest.php

@@ -48,7 +48,7 @@ public function testCachedQueryWithChangedImplementationIsExecutedTwice(): void
         )->fetchAllAssociative());
     }
 
-    /** @param list<array<string, mixed>> $data */
+    /** @param list<non-empty-array<string, mixed>> $data */
     private function createConnection(int $expectedQueryCount, array $data): Connection
     {
         $connection = $this->createMock(Driver\Connection::class);