feat(evaluate): serialize map and set (#26730)

closes: https://github.com/microsoft/playwright/issues/24040

packages/playwright-core/src/protocol/serializers.ts

@@ -75,6 +75,10 @@ function innerParseSerializedValue(value: SerializedValue, handles: any[] | unde
     return BigInt(value.bi);
   if (value.r !== undefined)
     return new RegExp(value.r.p, value.r.f);
+  if (value.m !== undefined)
+    return new Map(innerParseSerializedValue(value.m, handles, refs));
+  if (value.se !== undefined)
+    return new Set(innerParseSerializedValue(value.se, handles, refs));
 
   if (value.a !== undefined) {
     const result: any[] = [];
@@ -145,6 +149,10 @@ function innerSerializeValue(value: any, handleSerializer: (value: any) => Handl
     }
     return { s: `${error.name}: ${error.message}\n${error.stack}` };
   }
+  if (isMap(value))
+    return { m: innerSerializeValue(Array.from(value), handleSerializer, visitorInfo) };
+  if (isSet(value))
+    return { se: innerSerializeValue(Array.from(value), handleSerializer, visitorInfo) };
   if (isDate(value))
     return { d: value.toJSON() };
   if (isURL(value))
@@ -175,6 +183,14 @@ function innerSerializeValue(value: any, handleSerializer: (value: any) => Handl
   throw new Error('Unexpected value');
 }
 
+function isMap(obj: any): obj is Map<any, any> {
+  return obj instanceof Map || Object.prototype.toString.call(obj) === '[object Map]';
+}
+
+function isSet(obj: any): obj is Set<any> {
+  return obj instanceof Set || Object.prototype.toString.call(obj) === '[object Set]';
+}
+
 function isRegExp(obj: any): obj is RegExp {
   return obj instanceof RegExp || Object.prototype.toString.call(obj) === '[object RegExp]';
 }

packages/playwright-core/src/protocol/validator.ts

@@ -58,6 +58,8 @@ scheme.SerializedValue = tObject({
   d: tOptional(tString),
   u: tOptional(tString),
   bi: tOptional(tString),
+  m: tOptional(tType('SerializedValue')),
+  se: tOptional(tType('SerializedValue')),
   r: tOptional(tObject({
     p: tString,
     f: tString,

packages/playwright-core/src/server/isomorphic/utilityScriptSerializers.ts

@@ -20,6 +20,8 @@ export type SerializedValue =
     { d: string } |
     { u: string } |
     { bi: string } |
+    { m: SerializedValue } |
+    { se: SerializedValue } |
     { r: { p: string, f: string} } |
     { a: SerializedValue[], id: number } |
     { o: { k: string, v: SerializedValue }[], id: number } |
@@ -35,6 +37,14 @@ type VisitorInfo = {
 
 export function source() {
 
+  function isMap(obj: any): obj is Map<any, any> {
+    return obj instanceof Map || Object.prototype.toString.call(obj) === '[object Map]';
+  }
+
+  function isSet(obj: any): obj is Set<any> {
+    return obj instanceof Set || Object.prototype.toString.call(obj) === '[object Set]';
+  }
+
   function isRegExp(obj: any): obj is RegExp {
     try {
       return obj instanceof RegExp || Object.prototype.toString.call(obj) === '[object RegExp]';
@@ -94,6 +104,10 @@ export function source() {
         return new URL(value.u);
       if ('bi' in value)
         return BigInt(value.bi);
+      if ('m' in value)
+        return new Map(parseEvaluationResultValue(value.m));
+      if ('se' in value)
+        return new Set(parseEvaluationResultValue(value.se));
       if ('r' in value)
         return new RegExp(value.r.p, value.r.f);
       if ('a' in value) {
@@ -163,6 +177,11 @@ export function source() {
     if (typeof value === 'bigint')
       return { bi: value.toString() };
 
+    if (isMap(value))
+      return { m: serialize(Array.from(value), handleSerializer, visitorInfo) };
+    if (isSet(value))
+      return { se: serialize(Array.from(value), handleSerializer, visitorInfo) };
+
     if (isError(value)) {
       const error = value;
       if (error.stack?.startsWith(error.name + ': ' + error.message)) {

packages/protocol/src/channels.ts

@@ -180,6 +180,8 @@ export type SerializedValue = {
   d?: string,
   u?: string,
   bi?: string,
+  m?: SerializedValue,
+  se?: SerializedValue,
   r?: {
     p: string,
     f: string,

packages/protocol/src/protocol.yml

@@ -82,6 +82,10 @@ SerializedValue:
     u: string?
     # String representation of BigInt.
     bi: string?
+    # JS representation of Map: [[key1, value1], [key2, value2], ...].
+    m: SerializedValue?
+    # JS representation of Set: [item1, item2, ...].
+    se: SerializedValue?
     # Regular expression pattern and flags.
     r:
       type: object?

tests/page/page-evaluate.spec.ts

@@ -99,9 +99,14 @@ it('should transfer bigint', async ({ page }) => {
   expect(await page.evaluate(a => a, 17n)).toBe(17n);
 });
 
-it('should transfer maps as empty objects', async ({ page }) => {
+it('should transfer maps', async ({ page }) => {
-  const result = await page.evaluate(a => a.x.constructor.name + ' ' + JSON.stringify(a.x), { x: new Map([[1, 2]]) });
+  expect(await page.evaluate(() => new Map([[1, { test: 42n }]]))).toEqual(new Map([[1, { test: 42n }]]));
-  expect(result).toBe('Object {}');
+  expect(await page.evaluate(a => a, new Map([[1, { test: 17n }]]))).toEqual(new Map([[1, { test: 17n }]]));
+});
+
+it('should transfer sets', async ({ page }) => {
+  expect(await page.evaluate(() => new Set([1, { test: 42n }]))).toEqual(new Set([1, { test: 42n }]));
+  expect(await page.evaluate(a => a, new Set([1, { test: 17n }]))).toEqual(new Set([1, { test: 17n }]));
 });
 
 it('should modify global environment', async ({ page }) => {