fix: distinguish delimiters in queries from SQL comments (#22)

* fix: distinguish double dashes in queries from SQL comments

* test: add no backtick case

Author: wellwelwel

src/index.ts

@@ -29,6 +29,7 @@ const CHARS_ESCAPE_MAP: Record<string, string> = {
 
 const charCode = {
   singleQuote: 39,
+  backtick: 96,
   backslash: 92,
   dash: 45,
   slash: 47,
@@ -110,6 +111,23 @@ const skipSqlContext = (sql: string, position: number): number => {
     return sql.length;
   }
 
+  if (currentChar === charCode.backtick) {
+    const length = sql.length;
+
+    for (let cursor = position + 1; cursor < length; cursor++) {
+      if (sql.charCodeAt(cursor) !== charCode.backtick) continue;
+
+      if (sql.charCodeAt(cursor + 1) === charCode.backtick) {
+        cursor++;
+        continue;
+      }
+
+      return cursor + 1;
+    }
+
+    return length;
+  }
+
   if (currentChar === charCode.dash && nextChar === charCode.dash) {
     const lineBreak = sql.indexOf('\n', position + 2);
     return lineBreak === -1 ? sql.length : lineBreak + 1;
@@ -132,6 +150,7 @@ const findNextPlaceholder = (sql: string, start: number): number => {
 
     if (
       code === charCode.singleQuote ||
+      code === charCode.backtick ||
       code === charCode.dash ||
       code === charCode.slash
     ) {
@@ -153,6 +172,7 @@ const findSetKeyword = (sql: string, startFrom = 0): number => {
 
     if (
       code === charCode.singleQuote ||
+      code === charCode.backtick ||
       code === charCode.dash ||
       code === charCode.slash
     ) {

test/everyday-queries.test.ts

@@ -544,3 +544,75 @@ describe('Nice to have: Boolean in various contexts', () => {
     assert.equal(sql, 'UPDATE t SET `active` = true, `archived` = false');
   });
 });
+
+describe('Critical: Backtick-quoted identifiers with comment-like sequences', () => {
+  test('database/table names with double dashes', () => {
+    const sql = format(
+      'INSERT INTO `db--name`.`table`(`a`, `b`) VALUES (?, ?)',
+      [1, 'hello']
+    );
+    assert.equal(
+      sql,
+      "INSERT INTO `db--name`.`table`(`a`, `b`) VALUES (1, 'hello')"
+    );
+  });
+
+  test('column names with double dashes', () => {
+    const sql = format(
+      'INSERT INTO t (`col--1`, `col--2`) VALUES (?, ?)',
+      [1, 2]
+    );
+    assert.equal(sql, 'INSERT INTO t (`col--1`, `col--2`) VALUES (1, 2)');
+  });
+
+  test('backticks with block comment markers', () => {
+    const sql = format('INSERT INTO `table/*name*/` VALUES (?)', [1]);
+    assert.equal(sql, 'INSERT INTO `table/*name*/` VALUES (1)');
+  });
+
+  test('escaped backticks inside identifiers', () => {
+    const sql = format('INSERT INTO `table``name` VALUES (?)', [1]);
+    assert.equal(sql, 'INSERT INTO `table``name` VALUES (1)');
+  });
+
+  test('multiple backtick identifiers with mixed comment markers', () => {
+    const sql = format(
+      'SELECT * FROM `db--1`.`table/*test*/` WHERE `col--id` = ?',
+      [42]
+    );
+    assert.equal(
+      sql,
+      'SELECT * FROM `db--1`.`table/*test*/` WHERE `col--id` = 42'
+    );
+  });
+
+  test('UPDATE with backtick identifiers containing dashes', () => {
+    const sql = format('UPDATE `table--name` SET `col--1` = ? WHERE id = ?', [
+      'value',
+      1,
+    ]);
+    assert.equal(
+      sql,
+      "UPDATE `table--name` SET `col--1` = 'value' WHERE id = 1"
+    );
+  });
+
+  test('SELECT with ?? and backtick-quoted values with dashes', () => {
+    const sql = format('SELECT ?? FROM `users--table` WHERE id = ?', [
+      ['col--1', 'col--2'],
+      1,
+    ]);
+    assert.equal(
+      sql,
+      'SELECT `col--1`, `col--2` FROM `users--table` WHERE id = 1'
+    );
+  });
+
+  test('SELECT with ?? without any backticks in query', () => {
+    const sql = format('SELECT ?? FROM users WHERE id = ?', [
+      ['id', 'name'],
+      1,
+    ]);
+    assert.equal(sql, 'SELECT `id`, `name` FROM users WHERE id = 1');
+  });
+});