feat: metona-sqlark v0.1.12 — 前端TypeScript关系型数据库

- 4种存储引擎：Memory / IndexedDB / OPFS / Hybrid
- 完整SQL支持：SELECT/INSERT/UPDATE/DELETE/JOIN/GROUP BY/HAVING/DISTINCT
- Query Builder链式API + TypeScript泛型支持
- 聚合函数：COUNT/SUM/AVG/MIN/MAX
- 事务、插件系统(14 hooks)、发布订阅、数据迁移、导入导出
- React/Vue框架集成
- 264个测试用例，93.46%覆盖率
- 零运行时依赖

tests/sql/lexer.test.ts

@@ -0,0 +1,96 @@
+/**
+ * Lexer 边缘场景测试
+ */
+
+import { Lexer, tokenize } from '../../src/sql/lexer';
+import { TokenType } from '../../src/sql/tokens';
+
+describe('Lexer 边缘场景', () => {
+  it('空字符串返回 EOF', () => {
+    const tokens = tokenize('');
+    expect(tokens).toHaveLength(1);
+    expect(tokens[0].type).toBe(TokenType.EOF);
+  });
+
+  it('只包含空格', () => {
+    const tokens = tokenize('   \t\n  ');
+    expect(tokens).toHaveLength(1);
+    expect(tokens[0].type).toBe(TokenType.EOF);
+  });
+
+  it('非法字符返回 ILLEGAL', () => {
+    const tokens = tokenize('@');
+    expect(tokens[0].type).toBe(TokenType.ILLEGAL);
+  });
+
+  it('完整的 CREATE TABLE 语句', () => {
+    const tokens = tokenize('CREATE TABLE users (id STRING PRIMARY KEY, name STRING NOT NULL, age NUMBER DEFAULT 0)');
+    const types = tokens.map(t => t.type);
+    expect(types).toEqual([
+      TokenType.CREATE, TokenType.TABLE, TokenType.IDENTIFIER, TokenType.LPAREN,
+      TokenType.IDENTIFIER, TokenType.IDENTIFIER, TokenType.PRIMARY, TokenType.KEY,
+      TokenType.COMMA,
+      TokenType.IDENTIFIER, TokenType.IDENTIFIER, TokenType.NOT, TokenType.NULL,
+      TokenType.COMMA,
+      TokenType.IDENTIFIER, TokenType.IDENTIFIER, TokenType.DEFAULT, TokenType.NUMBER,
+      TokenType.RPAREN, TokenType.EOF,
+    ]);
+  });
+
+  it('带转义单引号的字符串', () => {
+    // SQL 中两个单引号 '' 表示转义的单引号
+    const tokens = tokenize("SELECT 'hello world'");
+    expect(tokens[1].type).toBe(TokenType.STRING);
+    expect(tokens[1].value).toBe('hello world');
+  });
+
+  it('双引号字符串', () => {
+    const tokens = tokenize('SELECT "hello world"');
+    expect(tokens[1].type).toBe(TokenType.STRING);
+    expect(tokens[1].value).toBe('hello world');
+  });
+
+  it('所有关键字', () => {
+    const sql = 'SELECT FROM WHERE INSERT INTO VALUES UPDATE SET DELETE CREATE TABLE DROP ORDER BY ASC DESC LIMIT OFFSET AND OR NOT LIKE IN PRIMARY KEY UNIQUE DEFAULT NULL TRUE FALSE';
+    const tokens = tokenize(sql);
+    const nonEof = tokens.filter(t => t.type !== TokenType.EOF);
+    expect(nonEof).toHaveLength(30);
+    // 验证都是关键字，不是 IDENTIFIER
+    for (const t of nonEof) {
+      expect(t.type).not.toBe(TokenType.IDENTIFIER);
+    }
+  });
+
+  it('下划线标识符', () => {
+    const tokens = tokenize('SELECT my_col_1 FROM user_table');
+    expect(tokens[1].type).toBe(TokenType.IDENTIFIER);
+    expect(tokens[1].value).toBe('my_col_1');
+    expect(tokens[3].type).toBe(TokenType.IDENTIFIER);
+    expect(tokens[3].value).toBe('user_table');
+  });
+
+  it('运算符分隔符', () => {
+    const tokens = tokenize('= != > >= < <= <> ( ) , ; *');
+    const types = tokens.map(t => t.type);
+    expect(types).toEqual([
+      TokenType.EQ, TokenType.NEQ, TokenType.GT, TokenType.GTE,
+      TokenType.LT, TokenType.LTE, TokenType.NEQ,
+      TokenType.LPAREN, TokenType.RPAREN, TokenType.COMMA,
+      TokenType.SEMICOLON, TokenType.STAR, TokenType.EOF,
+    ]);
+  });
+
+  it('数字: 整数和浮点数和负数', () => {
+    const tokens = tokenize('42 3.14 -7 -2.5');
+    expect(tokens[0].value).toBe('42');
+    expect(tokens[1].value).toBe('3.14');
+    expect(tokens[2].value).toBe('-7');
+    expect(tokens[3].value).toBe('-2.5');
+  });
+
+  it('Token position 正确', () => {
+    const lexer = new Lexer('SELECT * FROM users');
+    const tok = lexer.nextToken();
+    expect(tok.position).toBe(0); // SELECT 从位置 0 开始
+  });
+});