fix: serialize milliseconds for DateTime and EpochSeconds timestamp formats (#1289)

* fix: serialize milliseconds for DateTime and EpochSeconds timestamp formats

* fix(smithy-client): add date-time serializer function

* use truncating serializer function for datetime

* no truncation

* remove brackets

Co-authored-by: Trivikram Kamat <[email protected]>

* update Smithy link

---------

Co-authored-by: Trivikram Kamat <[email protected]>

Author: kuhe

.changeset/sweet-years-compete.md

@@ -0,0 +1,5 @@
+---
+"@smithy/smithy-client": minor
+---
+
+add dateTime serializer function

packages/smithy-client/src/ser-utils.spec.ts

@@ -1,4 +1,4 @@
-import { serializeFloat } from "./ser-utils";
+import { serializeDateTime, serializeFloat } from "./ser-utils";
 
 describe("serializeFloat", () => {
   it("handles non-numerics", () => {
@@ -12,3 +12,16 @@ describe("serializeFloat", () => {
     expect(serializeFloat(1.1)).toEqual(1.1);
   });
 });
+
+describe("serializeDateTime", () => {
+  it("should not truncate at the top of the second", () => {
+    const date = new Date(1716476757761);
+    date.setMilliseconds(0);
+    expect(serializeDateTime(date)).toEqual("2024-05-23T15:05:57.000Z");
+  });
+
+  it("should not truncate in general", () => {
+    const date = new Date(1716476757761);
+    expect(serializeDateTime(date)).toEqual("2024-05-23T15:05:57.761Z");
+  });
+});

packages/smithy-client/src/ser-utils.ts

@@ -20,3 +20,9 @@ export const serializeFloat = (value: number): string | number => {
       return value;
   }
 };
+
+/**
+ * @param date - to be serialized.
+ * @returns https://smithy.io/2.0/spec/protocol-traits.html#timestampformat-trait date-time format.
+ */
+export const serializeDateTime = (date: Date): string => date.toISOString();

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/integration/HttpProtocolGeneratorUtils.java

@@ -79,16 +79,23 @@ public static String getTimestampInputParam(
     ) {
         switch (format) {
             case DATE_TIME:
-                // Use the split to not serialize milliseconds.
-                return "(" + dataSource + ".toISOString().split('.')[0]+\"Z\")";
+                context.getWriter().addImport(
+                    "serializeDateTime",
+                    "__serializeDateTime",
+                    TypeScriptDependency.AWS_SMITHY_CLIENT
+                );
+                return "__serializeDateTime(" + dataSource + ")";
             case EPOCH_SECONDS:
-                return "Math.round(" + dataSource + ".getTime() / 1000)";
+                return "(" + dataSource + ".getTime() / 1_000)";
             case HTTP_DATE:
-                context.getWriter().addImport("dateToUtcString", "__dateToUtcString",
-                    TypeScriptDependency.AWS_SMITHY_CLIENT);
+                context.getWriter().addImport(
+                    "dateToUtcString",
+                    "__dateToUtcString",
+                    TypeScriptDependency.AWS_SMITHY_CLIENT
+                );
                 return "__dateToUtcString(" + dataSource + ")";
             default:
-                throw new CodegenException("Unexpected timestamp format `" + format.toString() + "` on " + shape);
+                throw new CodegenException("Unexpected timestamp format `" + format + "` on " + shape);
         }
     }
 

smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/integration/HttpProtocolGeneratorUtilsTest.java

@@ -28,9 +28,9 @@ public void givesCorrectTimestampSerialization() {
         mockContext.setWriter(writer);
         TimestampShape shape = TimestampShape.builder().id("com.smithy.example#Foo").build();
 
-        assertThat("(" + DATA_SOURCE + ".toISOString().split('.')[0]+\"Z\")",
+        assertThat("__serializeDateTime(" + DATA_SOURCE + ")",
                 equalTo(HttpProtocolGeneratorUtils.getTimestampInputParam(mockContext, DATA_SOURCE, shape, Format.DATE_TIME)));
-        assertThat("Math.round(" + DATA_SOURCE + ".getTime() / 1000)",
+        assertThat("(" + DATA_SOURCE + ".getTime() / 1_000)",
                 equalTo(HttpProtocolGeneratorUtils.getTimestampInputParam(mockContext, DATA_SOURCE, shape, Format.EPOCH_SECONDS)));
         assertThat("__dateToUtcString(" + DATA_SOURCE + ")",
                 equalTo(HttpProtocolGeneratorUtils.getTimestampInputParam(mockContext, DATA_SOURCE, shape, Format.HTTP_DATE)));