fix: Date and LocalDateTime serialization in post data (#1150)

Author: yury-s

playwright/src/main/java/com/microsoft/playwright/impl/Serialization.java

@@ -32,9 +32,13 @@
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
 import java.time.Instant;
 import java.time.LocalDateTime;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
 import java.util.*;
 import java.util.regex.Pattern;
 
@@ -43,6 +47,8 @@
 
 class Serialization {
   private static final Gson gson = new GsonBuilder().disableHtmlEscaping()
+    .registerTypeAdapter(Date.class, new DateSerializer())
+    .registerTypeAdapter(LocalDateTime.class, new LocalDateTimeSerializer())
     .registerTypeAdapter(SameSiteAttribute.class, new SameSiteAdapter().nullSafe())
     .registerTypeAdapter(BrowserChannel.class, new ToLowerCaseAndDashSerializer<BrowserChannel>())
     .registerTypeAdapter(ColorScheme.class, new ToLowerCaseAndDashSerializer<ColorScheme>())
@@ -468,5 +474,29 @@ public SameSiteAttribute read(JsonReader in) throws IOException {
       return SameSiteAttribute.valueOf(value.toUpperCase());
     }
   }
+
+  private static DateFormat iso8601Format() {
+    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.getDefault());
+    dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    return dateFormat;
+  }
+  private static final DateFormat dateFormat = iso8601Format();
+
+  private static class DateSerializer implements JsonSerializer<Date> {
+    @Override
+    public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
+      return new JsonPrimitive(dateFormat.format(src));
+    }
+  }
+
+  private static class LocalDateTimeSerializer implements JsonSerializer<LocalDateTime> {
+    @Override
+    public JsonElement serialize(LocalDateTime src, Type typeOfSrc, JsonSerializationContext context) {
+      ZoneOffset offset = ZoneId.systemDefault().getRules().getOffset(src);
+      Instant instant = src.toInstant(offset);
+      return new JsonPrimitive(dateFormat.format(Date.from(instant)));
+    }
+  }
+
 }
 

playwright/src/test/java/com/microsoft/playwright/TestBrowserContextFetch.java

@@ -9,6 +9,9 @@
 import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
+import java.text.ParseException;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
 import java.util.*;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -479,6 +482,28 @@ void shouldOverrideRequestParameters() throws ExecutionException, InterruptedExc
     assertEquals("data", new String(req.get().postBody));
   }
 
+  public static class TestData {
+    public String name;
+    public LocalDateTime localDateTime;
+    public Date date;
+    public LocalDateTime nullLocalDateTime;
+    public Date nullDate;
+  }
+
+  @Test
+  void shouldSerializeDateAndLocalDateTime() throws ExecutionException, InterruptedException, ParseException {
+    Request pageReq = page.waitForRequest("**/*", () -> page.navigate(server.EMPTY_PAGE));
+    Future<Server.Request> req = server.futureRequest("/empty.html");
+    TestData testData = new TestData();
+    testData.name = "foo";
+    long currentMillis = 1671776098818L;
+    testData.date = new Date(currentMillis);
+    testData.localDateTime = testData.date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();
+    context.request().fetch(pageReq, RequestOptions.create().setMethod("POST").setData(testData));
+    assertEquals("{\"name\":\"foo\",\"localDateTime\":\"2022-12-23T06:14:58.818Z\",\"date\":\"2022-12-23T06:14:58.818Z\"}",
+      new String(req.get().postBody));
+  }
+
   @Test
   void shouldSupportApplicationXWwwFormUrlencoded() throws ExecutionException, InterruptedException {
     Future<Server.Request> req = server.futureRequest("/empty.html");