feat: support Date, Set, and Map to literalToAst

Author: antfu

src/proxy/_utils.ts

@@ -64,16 +64,44 @@ export function proxify<T>(node: ESNode): Proxified<T> {
 
 const PROXY_KEY = "__magicast_proxy";
 
-export function literalToAst(value: any): ESNode {
+export function literalToAst(value: any, seen = new Set()): ESNode {
   if (value === undefined) {
     return b.identifier("undefined") as any;
   }
   if (value === null) {
     // eslint-disable-next-line unicorn/no-null
     return b.literal(null) as any;
   }
+  if (seen.has(value)) {
+    throw new Error("Can not serialize circular reference");
+  }
+  seen.add(value);
+  if (value instanceof Set) {
+    return b.newExpression(b.identifier("Set"), [
+      b.arrayExpression([...value].map((n) => literalToAst(n, seen)) as any),
+    ]) as any;
+  }
+  if (value instanceof Date) {
+    return b.newExpression(b.identifier("Date"), [
+      b.literal(value.toISOString()),
+    ]) as any;
+  }
+  if (value instanceof Map) {
+    return b.newExpression(b.identifier("Map"), [
+      b.arrayExpression(
+        [...value].map(([key, value]) => {
+          return b.arrayExpression([
+            literalToAst(key, seen) as any,
+            literalToAst(value, seen) as any,
+          ]) as any;
+        }) as any
+      ),
+    ]) as any;
+  }
   if (Array.isArray(value)) {
-    return b.arrayExpression(value.map((n) => literalToAst(n)) as any) as any;
+    return b.arrayExpression(
+      value.map((n) => literalToAst(n, seen)) as any
+    ) as any;
   }
   if (typeof value === "object") {
     if (PROXY_KEY in value) {
@@ -84,7 +112,7 @@ export function literalToAst(value: any): ESNode {
         return b.property(
           "init",
           b.identifier(key),
-          literalToAst(value) as any
+          literalToAst(value, seen) as any
         ) as any;
       })
     ) as any;

test/utils.test.ts

@@ -8,7 +8,7 @@ describe("literalToAst", () => {
     return print(literalToAst(value)).code;
   }
 
-  it("should work", () => {
+  it("basic", () => {
     expect(run(1)).toMatchInlineSnapshot('"1"');
     expect(run(true)).toMatchInlineSnapshot('"true"');
     expect(run(undefined)).toMatchInlineSnapshot('"undefined"');
@@ -20,4 +20,27 @@ describe("literalToAst", () => {
       }]"
     `);
   });
+
+  it("built-in objects", () => {
+    expect(run(new Set(["foo", 1]))).toMatchInlineSnapshot(
+      '"new Set([\\"foo\\", 1])"'
+    );
+
+    expect(run(new Date("2010-01-01"))).toMatchInlineSnapshot(
+      '"new Date(\\"2010-01-01T00:00:00.000Z\\")"'
+    );
+
+    const map = new Map();
+    map.set(1, "foo");
+    map.set(2, "bar");
+    expect(run(map)).toMatchInlineSnapshot(
+      '"new Map([[1, \\"foo\\"], [2, \\"bar\\"]])"'
+    );
+  });
+
+  it("circular reference", () => {
+    const obj: any = {};
+    obj.foo = obj;
+    expect(() => run(obj)).toThrowError("Can not serialize circular reference");
+  });
 });