fix(parser): add spaces around 'in' and 'instanceof' operators

- Fix generate function to properly handle keyword operators by adding spaces
- Add unit tests for 'in' and 'instanceof' operators in parser tests
- Ensure 'in' operator works correctly in boolean expressions

Author: codehz

src/integration.boolean.test.ts

@@ -254,4 +254,17 @@ describe("集成测试：布尔表达式", () => {
       }
     });
   });
+
+  describe("in 运算符", () => {
+    test("检查对象属性", () => {
+      const obj = variable(z.record(z.string(), z.number()));
+      const key = variable(z.string());
+
+      const hasKey = expr({ key, obj })("key in obj");
+      const compiled = compile(hasKey, { key, obj });
+
+      expect(evaluate<boolean>(compiled, { key: "a", obj: { a: 1, b: 2 } })).toBe(true);
+      expect(evaluate<boolean>(compiled, { key: "c", obj: { a: 1, b: 2 } })).toBe(false);
+    });
+  });
 });

src/parser.test.ts

@@ -51,6 +51,12 @@ test("parse: logical operators", () => {
   expect(generate(parse("a ?? b"))).toBe("a??b");
 });
 
+test("parse: keyword operators (in, instanceof)", () => {
+  expect(generate(parse("key in obj"))).toBe("key in obj");
+  expect(generate(parse("value instanceof Array"))).toBe("value instanceof Array");
+  expect(generate(parse("'prop' in object"))).toBe('"prop" in object');
+});
+
 test("parse: unary expressions", () => {
   expect(generate(parse("!a"))).toBe("!a");
   expect(generate(parse("-a"))).toBe("-a");

src/parser.ts

@@ -706,6 +706,10 @@ export function generate(node: ASTNode): string {
     case "BinaryExpr": {
       const left = wrapIfNeeded(node.left, node, "left");
       const right = wrapIfNeeded(node.right, node, "right");
+      // 关键字运算符需要空格
+      if (node.operator === "in" || node.operator === "instanceof") {
+        return `${left} ${node.operator} ${right}`;
+      }
       return `${left}${node.operator}${right}`;
     }