Added table name validation

Validation added for
- invalid characters
- invalid names ("C", "c", "R", or "r")
- cell references
- space separate words
- maxlength of 255 characters
- unique table names across worksheet

samples/Table/01_Table.php

@@ -53,7 +53,7 @@ $spreadsheet->getActiveSheet()->fromArray($dataArray, null, 'A2');
 // Create Table
 $helper->log('Create Table');
 $table = new Table();
-$table->setName('Sales Data');
+$table->setName('Sales_Data');
 $table->setRange('A1:D17');
 
 // Create Columns

src/PhpSpreadsheet/Worksheet/Table.php

@@ -88,7 +88,29 @@ class Table
      */
     public function setName(string $name)
     {
-        $this->name = preg_replace('/\s+/', '_', trim($name)) ?? '';
+        $name = trim($name);
+
+        if (strlen($name) == 1 && in_array($name, ['C', 'c', 'R', 'r'])) {
+            throw new PhpSpreadsheetException('The table name is invalid');
+        }
+        if (strlen($name) > 255) {
+            throw new PhpSpreadsheetException('The table name cannot be longer than 255 characters');
+        }
+        // Check for A1 or R1C1 cell reference notation
+        if (
+            preg_match(Coordinate::A1_COORDINATE_REGEX, $name) ||
+            preg_match('/^R\[?\-?[0-9]*\]?C\[?\-?[0-9]*\]?$/i', $name)
+        ) {
+            throw new PhpSpreadsheetException('The table name can\'t be the same as a cell reference');
+        }
+        if (!preg_match('/^[A-Z_\\\\]/i', $name)) {
+            throw new PhpSpreadsheetException('The table name must begin a name with a letter, an underscore character (_), or a backslash (\)');
+        }
+        if (!preg_match('/^[A-Z_\\\\][A-Z0-9\._]+$/i', $name)) {
+            throw new PhpSpreadsheetException('The table name contains invalid characters');
+        }
+
+        $this->name = $name;
 
         return $this;
     }
@@ -216,6 +238,18 @@ class Table
      */
     public function setWorksheet(?Worksheet $worksheet = null)
     {
+        if ($this->name != '' && $worksheet != null) {
+            $spreadsheet = $worksheet->getParent();
+
+            foreach ($spreadsheet->getWorksheetIterator() as $sheet) {
+                foreach ($sheet->getTableCollection() as $table) {
+                    if ($table->getName() == $this->name) {
+                        throw new PhpSpreadsheetException("Workbook already contains a table named '{$this->name}'");
+                    }
+                }
+            }
+        }
+
         $this->workSheet = $worksheet;
 
         return $this;

tests/PhpSpreadsheetTests/Worksheet/Table/TableTest.php

@@ -22,15 +22,78 @@ class TableTest extends SetupTeardown
         self::assertEquals($expectedResult, $result);
     }
 
-    public function testVariousSets(): void
+    /**
+     * @dataProvider validTableNamesProvider
+     */
+    public function testValidTableNames(string $name, string $expected): void
     {
         $sheet = $this->getSheet();
         $table = new Table(self::INITIAL_RANGE, $sheet);
 
-        $result = $table->setName('Table 1');
+        $result = $table->setName($name);
         self::assertInstanceOf(Table::class, $result);
-        // Spaces will be converted to underscore
-        self::assertEquals('Table_1', $table->getName());
+        self::assertEquals($expected, $table->getName());
+    }
+
+    public function validTableNamesProvider(): array
+    {
+        return [
+            ['Table_1', 'Table_1'],
+            ['_table_2', '_table_2'],
+            ['\table_3', '\table_3'],
+            ["	Table_4 \n", 'Table_4'],
+        ];
+    }
+
+    /**
+     * @dataProvider invalidTableNamesProvider
+     */
+    public function testInvalidTableNames(string $name): void
+    {
+        $sheet = $this->getSheet();
+        $table = new Table(self::INITIAL_RANGE, $sheet);
+
+        $this->expectException(PhpSpreadsheetException::class);
+
+        $table->setName($name);
+    }
+
+    public function invalidTableNamesProvider(): array
+    {
+        return [
+            ['C'],
+            ['c'],
+            ['R'],
+            ['r'],
+            ['Z100'],
+            ['Z$100'],
+            ['R1C1'],
+            ['R1C'],
+            ['R11C11'],
+            ['123'],
+            ['=Table'],
+            [bin2hex(random_bytes(255))], // random string with length greater than 255
+        ];
+    }
+
+    public function testUniqueTableName(): void
+    {
+        $this->expectException(PhpSpreadsheetException::class);
+        $sheet = $this->getSheet();
+
+        $table1 = new Table();
+        $table1->setName('Table_1');
+        $sheet->addTable($table1);
+
+        $table2 = new Table();
+        $table2->setName('Table_1');
+        $sheet->addTable($table2);
+    }
+
+    public function testVariousSets(): void
+    {
+        $sheet = $this->getSheet();
+        $table = new Table(self::INITIAL_RANGE, $sheet);
 
         $result = $table->setShowHeaderRow(false);
         self::assertInstanceOf(Table::class, $result);