chore(api): 移除多余类型断言并简化代理返回

详细的提交内容：
- 去掉 `getProxyMetadata`、`parse`、`variableIds.set` 等位置的多余 `as object` /
  `as string` 类型断言，直接使用推导类型
- 精简 `lambda` 与模板表达式相关实现，移除不必要的显式返回类型断言
- 调整 `serializeArgumentToAST` 中基础字面量节点的构造方式，减少对 AST 类型的冗余强转
- 同步更新单元测试中的调用方式，确保测试覆盖新的类型推导写法
- 这次改动主要用于提升代码可读性与类型推导一致性，降低后续维护成本
- 影响范围：`api`、`proxy` 及相关单元测试

Author: codehz

src/__tests__/unit/proxy-variable.test.ts

@@ -8,7 +8,7 @@ describe("代理变量 单元测试", () => {
   test("创建代理变量", () => {
     const x = variable<number>();
     expect(typeof x).toBe("function"); // Proxy wraps function
-    const meta = getProxyMetadata(x as object);
+    const meta = getProxyMetadata(x);
     expect(meta?.type).toBe("variable");
   });
 
@@ -20,7 +20,7 @@ describe("代理变量 单元测试", () => {
     const config = variable<Config>();
     const timeout = config.timeout;
 
-    const meta = getProxyMetadata(timeout as object);
+    const meta = getProxyMetadata(timeout);
     expect(meta?.type).toBe("expression");
     expect(meta?.ast).toBeDefined();
     if (meta?.ast) {
@@ -47,7 +47,7 @@ describe("代理变量 单元测试", () => {
     const builder = variable<Builder>();
     const result = builder.build("test");
 
-    const meta = getProxyMetadata(result as object);
+    const meta = getProxyMetadata(result);
     expect(meta?.type).toBe("expression");
     expect(meta?.ast).toBeDefined();
     if (meta?.ast) {
@@ -153,7 +153,7 @@ describe("代理变量 单元测试", () => {
     const ui = variable<UI>();
     const configured = ui.configure({ padding: 10, margin: 5 });
 
-    const meta = getProxyMetadata(configured as object);
+    const meta = getProxyMetadata(configured);
     expect(meta?.ast).toBeDefined();
     if (meta?.ast) {
       const source = generate(meta.ast);

src/__tests__/unit/template.test.ts

@@ -9,7 +9,7 @@ describe("模板标签 单元测试", () => {
     const name = variable<string>();
     const greeting = t`Hello, ${name}!`;
 
-    const meta = getProxyMetadata(greeting as object);
+    const meta = getProxyMetadata(greeting);
     expect(meta?.type).toBe("expression");
     expect(meta?.ast).toBeDefined();
     if (meta?.ast) {

src/__tests__/unit/type-parser.test.ts

@@ -121,7 +121,7 @@ describe("type-parser 单元测试", () => {
       const _y = variable<number>();
 
       const _sum = expr({ x: _x, y: _y })("x + y");
-      const meta = getProxyMetadata(_sum as object);
+      const meta = getProxyMetadata(_sum);
 
       // 验证元数据
       expect(meta?.type).toBe("expression");
@@ -134,7 +134,7 @@ describe("type-parser 单元测试", () => {
 
       const _sum = expr({ x: _x, y: _y })("x + y");
       const _doubled = expr({ sum: _sum })("sum * 2");
-      const meta = getProxyMetadata(_doubled as object);
+      const meta = getProxyMetadata(_doubled);
 
       expect(meta?.type).toBe("expression");
       expect(meta?.ast).toBeDefined();
@@ -144,7 +144,7 @@ describe("type-parser 单元测试", () => {
       const _age = variable<number>();
 
       const _isAdult = expr({ age: _age })("age >= 18");
-      const meta = getProxyMetadata(_isAdult as object);
+      const meta = getProxyMetadata(_isAdult);
 
       expect(meta?.type).toBe("expression");
       expect(meta?.ast).toBeDefined();
@@ -156,7 +156,7 @@ describe("type-parser 单元测试", () => {
 
       // (x + y) * 2 - 1
       const _complex = expr({ x: _x, y: _y })("(x + y) * 2 - 1");
-      const meta = getProxyMetadata(_complex as object);
+      const meta = getProxyMetadata(_complex);
 
       expect(meta?.type).toBe("expression");
       expect(meta?.ast).toBeDefined();
@@ -167,7 +167,7 @@ describe("type-parser 单元测试", () => {
       const _b = variable<boolean>();
 
       const _result = expr({ a: _a, b: _b })("a && b || !a");
-      const meta = getProxyMetadata(_result as object);
+      const meta = getProxyMetadata(_result);
 
       // 逻辑表达式最终返回 boolean
       expect(meta?.type).toBe("expression");
@@ -179,7 +179,7 @@ describe("type-parser 单元测试", () => {
       const _lastName = variable<string>();
 
       const _fullName = expr({ firstName: _firstName, lastName: _lastName })("firstName + lastName");
-      const meta = getProxyMetadata(_fullName as object);
+      const meta = getProxyMetadata(_fullName);
 
       expect(meta?.type).toBe("expression");
       expect(meta?.ast).toBeDefined();
@@ -195,8 +195,8 @@ describe("type-parser 单元测试", () => {
       const _sum = expr({ x: _x, y: _y })("x + y");
       const _isPositive = expr({ sum: _sum })("sum > 0");
 
-      const sumMeta = getProxyMetadata(_sum as object);
-      const isPositiveMeta = getProxyMetadata(_isPositive as object);
+      const sumMeta = getProxyMetadata(_sum);
+      const isPositiveMeta = getProxyMetadata(_isPositive);
 
       expect(sumMeta?.type).toBe("expression");
       expect(isPositiveMeta?.type).toBe("expression");

src/api/expr.ts

@@ -92,7 +92,7 @@ export function expr<TContext extends Record<string, unknown>>(
     }
 
     // 解析用户输入的字符串为 AST
-    const ast = parse(source as string);
+    const ast = parse(source);
 
     // 统计每个标识符的引用次数，用于决定是否内联
     const refCounts = new Map<string, number>();

src/api/lambda.ts

@@ -96,7 +96,7 @@ export function lambda<Args extends unknown[], R>(builder: LambdaBuilder<Args, R
     });
   }
 
-  return lambdaProxy as Lambda<Args, R>;
+  return lambdaProxy;
 }
 
 /**

src/api/template.ts

@@ -1,6 +1,6 @@
 import { collectDepsFromArgs, createProxyExpressionWithAST, serializeArgumentToAST } from "../proxy/proxy-variable";
 import type { Proxify } from "../types";
-import type { ASTNode, BinaryExpr, StringLiteral } from "../types/ast-types";
+import type { ASTNode, StringLiteral } from "../types/ast-types";
 
 /**
  * Tagged template 函数，用于创建包含变量的字符串表达式
@@ -33,7 +33,7 @@ export function t(strings: TemplateStringsArray, ...values: unknown[]): Proxify<
         type: "StringLiteral",
         value: str,
         quote: '"',
-      } as StringLiteral);
+      });
     }
 
     if (i < values.length) {
@@ -66,7 +66,7 @@ export function t(strings: TemplateStringsArray, ...values: unknown[]): Proxify<
       operator: "+",
       left: resultAst,
       right: parts[i]!,
-    } as BinaryExpr;
+    };
   }
 
   return createProxyExpressionWithAST<string>(resultAst, deps);

src/api/variable.ts

@@ -25,7 +25,7 @@ let variableCounter = 0;
 export function variable<T>(): Variable<T> {
   const id = Symbol(`var_${variableCounter++}`);
   const proxy = createProxyVariable<T>(id);
-  variableIds.set(proxy as object, id);
+  variableIds.set(proxy, id);
   return proxy;
 }
 

src/proxy/proxy-variable.ts

@@ -3,13 +3,10 @@ import type { Proxify } from "../types";
 import type {
   ArrayExpr,
   ASTNode,
-  BooleanLiteral,
   CallExpr,
   Identifier,
   MemberExpr,
-  NullLiteral,
   NumberLiteral,
-  ObjectExpr,
   Placeholder,
   StringLiteral,
 } from "../types/ast-types";
@@ -205,13 +202,13 @@ export function serializeArgumentToAST(arg: unknown): ASTNode {
       const key: ASTNode = isValidIdentifier ? identifier(k) : stringLiteral(k);
       return { key, value: serializeArgumentToAST(v), computed: false, shorthand: false };
     });
-    return { type: "ObjectExpr", properties } as ObjectExpr;
+    return { type: "ObjectExpr", properties };
   }
 
   // 4. 原始值
-  if (arg === null) return { type: "NullLiteral" } as NullLiteral;
+  if (arg === null) return { type: "NullLiteral" };
   if (arg === undefined) return identifier("undefined");
-  if (typeof arg === "boolean") return { type: "BooleanLiteral", value: arg } as BooleanLiteral;
+  if (typeof arg === "boolean") return { type: "BooleanLiteral", value: arg };
   if (typeof arg === "number") return numberLiteral(arg);
   if (typeof arg === "string") return stringLiteral(arg);
   if (typeof arg === "bigint") return callExpr(identifier("BigInt"), [stringLiteral(arg.toString())]);