Fix timestamp 96's nsec to be unsignd

gfx · gfx · commit ae345525228d · 2019-05-06T22:46:28.000+09:00
msgpack/msgpack#266
diff --git a/src/ExtensionCodec.ts b/src/ExtensionCodec.ts
@@ -36,21 +36,29 @@ export function encodeTimestampFromTimeSpec({ sec, nsec }: TimeSpec): Uint8Array
       return rv;
     }
   } else {
-    // timestamp 96 = { nsec32 (signed), sec64 (signed) }
+    // timestamp 96 = { nsec32 (unsigned), sec64 (signed) }
     const rv = new Uint8Array(12);
     const view = new DataView(rv.buffer);
-    view.setInt32(0, nsec);
+    view.setUint32(0, nsec);
     encodeInt64(sec, view, 4);
     return rv;
   }
 }
 
+export function encodeDateToTimeSpec(date: Date): TimeSpec {
+  const time = date.getTime();
+  const sec = time < 0 ? Math.ceil(time / 1000) : Math.floor(time / 1000);
+  const nsec = (time - sec * 1000) * 1e6;
+  return {
+    sec: sec + Math.floor(nsec / 1e9),
+    nsec: nsec - Math.floor(nsec / 1e9) * 1e9,
+  };
+}
+
 export const encodeTimestampExtension: ExtensionEncoderType = (object: unknown) => {
   if (isDate(object)) {
-    const time = object.getTime();
-    const sec = time < 0 ? Math.ceil(time / 1000) : Math.floor(time / 1000);
-    const nsec = (time - sec * 1000) * 1e6;
-    return encodeTimestampFromTimeSpec({ sec, nsec });
+    const timeSpec = encodeDateToTimeSpec(object);
+    return encodeTimestampFromTimeSpec(timeSpec);
   } else {
     return null;
   }
@@ -77,10 +85,10 @@ export const decodeTimestampExtension: ExtensionDecoderType = (data: Uint8Array)
       return new Date(sec * 1000 + nsec / 1e6);
     }
     case 12: {
-      // timestamp 96 = { nsec32 (signed), sec64 (signed) }
+      // timestamp 96 = { nsec32 (unsigned), sec64 (signed) }
       const view = new DataView(data.buffer, data.byteOffset, data.byteLength);
 
-      const nsec = view.getInt32(0);
+      const nsec = view.getUint32(0);
       const sec = decodeInt64(data[4], data[5], data[6], data[7], data[8], data[9], data[10], data[11]);
 
       return new Date(sec * 1000 + nsec / 1e6);
diff --git a/test/codec-timestamp.test.ts b/test/codec-timestamp.test.ts
@@ -1,6 +1,7 @@
 import assert from "assert";
 import util from "util";
 import { encode, decode } from "../src";
+import { encodeDateToTimeSpec } from "../src/ExtensionCodec";
 
 const TIME = 1556636810389;
 
@@ -17,13 +18,21 @@ const SPECS = {
   REGRESSION_1: new Date(1556799054803),
 } as Record<string, Date>;
 
-describe("codec: timestamp 32/64/96", () => {
-  for (const name of Object.keys(SPECS)) {
-    const value = SPECS[name];
+describe("codec: timestamp", () => {
+  context("timestamp 32/64/96", () => {
+    for (const name of Object.keys(SPECS)) {
+      const value = SPECS[name];
 
-    it(`encodes and decodes ${name} (${value.toISOString()})`, () => {
-      const encoded = encode(value);
-      assert.deepStrictEqual(decode(encoded), value, `encoded: ${util.inspect(Buffer.from(encoded))}`);
+      it(`encodes and decodes ${name} (${value.toISOString()})`, () => {
+        const encoded = encode(value);
+        assert.deepStrictEqual(decode(encoded), value, `encoded: ${util.inspect(Buffer.from(encoded))}`);
+      });
+    }
+  });
+
+  context("encodeDateToTimeSpec", () => {
+    it("normalizes new Date(-1) to { sec: -1, nsec: 999000000 }", () => {
+      assert.deepStrictEqual(encodeDateToTimeSpec(new Date(-1)), { sec: -1, nsec: 999000000 });
     });
-  }
+  });
 });
