feat: support builder.newExpression

Author: antfu

src/builders.ts

@@ -1,5 +1,6 @@
 import * as recast from "recast";
 import { proxifyFunctionCall } from "./proxy/function-call";
+import { proxifyNewExpression } from "./proxy/new-expression";
 import { literalToAst } from "./proxy/_utils";
 import { Proxified } from "./types";
 import { parseExpression } from "./code";
@@ -17,6 +18,16 @@ export const builders = {
     );
     return proxifyFunctionCall(node as any);
   },
+  /**
+   * Create a new expression node.
+   */
+  newExpression(callee: string, ...args: any[]): Proxified {
+    const node = b.newExpression(
+      b.identifier(callee),
+      args.map((i) => literalToAst(i) as any)
+    );
+    return proxifyNewExpression(node as any);
+  },
   /**
    * Create a proxified version of a literal value.
    */

src/proxy/new-expression.ts

@@ -0,0 +1,38 @@
+import { ASTNode } from "../types";
+import { MagicastError } from "../error";
+import { createProxy } from "./_utils";
+import { proxifyArrayElements } from "./array";
+import { ProxifiedModule, ProxifiedNewExpression } from "./types";
+
+export function proxifyNewExpression<T extends []>(
+  node: ASTNode,
+  mod?: ProxifiedModule
+): ProxifiedNewExpression<T> {
+  if (node.type !== "NewExpression") {
+    throw new MagicastError("Not a new expression");
+  }
+
+  function stringifyExpression(node: ASTNode): string {
+    if (node.type === "Identifier") {
+      return node.name;
+    }
+    if (node.type === "MemberExpression") {
+      return `${stringifyExpression(node.object)}.${stringifyExpression(
+        node.property
+      )}`;
+    }
+    throw new MagicastError("Not implemented");
+  }
+
+  const argumentsProxy = proxifyArrayElements<T>(node, node.arguments, mod);
+
+  return createProxy(
+    node,
+    {
+      $type: "new-expression",
+      $callee: stringifyExpression(node.callee as any),
+      $args: argumentsProxy,
+    },
+    {}
+  ) as ProxifiedNewExpression<T>;
+}

src/proxy/proxify.ts

@@ -3,6 +3,7 @@ import { ASTNode } from "../types";
 import { proxifyArray } from "./array";
 import { proxifyFunctionCall } from "./function-call";
 import { proxifyObject } from "./object";
+import { proxifyNewExpression } from "./new-expression";
 import { Proxified, ProxifiedModule, ProxifiedValue } from "./types";
 import { LITERALS_AST, LITERALS_TYPEOF } from "./_utils";
 
@@ -34,6 +35,10 @@ export function proxify<T>(node: ASTNode, mod?: ProxifiedModule): Proxified<T> {
       proxy = proxifyFunctionCall(node, mod);
       break;
     }
+    case "NewExpression": {
+      proxy = proxifyNewExpression(node, mod);
+      break;
+    }
     default:
       throw new MagicastError(`Casting "${node.type}" is not supported`, {
         ast: node,

src/proxy/types.ts

@@ -23,6 +23,13 @@ export type ProxifiedFunctionCall<Args extends any[] = unknown[]> =
     $callee: string;
   };
 
+export type ProxifiedNewExpression<Args extends any[] = unknown[]> =
+  ProxyBase & {
+    $type: "new-expression";
+    $args: ProxifiedArray<Args>;
+    $callee: string;
+  };
+
 export type ProxifiedObject<T extends object = object> = {
   [K in keyof T]: Proxified<T[K]>;
 } & ProxyBase & {
@@ -86,6 +93,7 @@ export interface ImportItemInput {
 export type ProxifiedValue =
   | ProxifiedArray
   | ProxifiedFunctionCall
+  | ProxifiedNewExpression
   | ProxifiedObject
   | ProxifiedModule
   | ProxifiedImportsMap

test/builders.test.ts

@@ -29,6 +29,32 @@ describe("builders", () => {
     `);
   });
 
+  it("new expression", () => {
+    const call = builders.newExpression("Foo", 1, "bar", {
+      foo: "bar",
+    });
+    expect(call.$type).toBe("new-expression");
+    expect(call.$callee).toBe("Foo");
+    expect(call.$args).toMatchInlineSnapshot(`
+      [
+        1,
+        "bar",
+        {
+          "foo": "bar",
+        },
+      ]
+    `);
+
+    const mod = parseModule("");
+    mod.exports.a = call;
+
+    expect(generate(mod)).toMatchInlineSnapshot(`
+      "export const a = new Foo(1, \\"bar\\", {
+        foo: \\"bar\\",
+      });"
+    `);
+  });
+
   it("raw", () => {
     const expression = builders.raw("{ foo: 1 }");
     expect(expression.$type).toBe("object");