fix #531 time.secondsAndNanoseconds (#533)

Correct Time.secondsAndNanoseconds error

Currently, after calling function secondsAndNanoseconds of Time object, the value of it will be changed which should keep the same as it is.

This patch corrects this wrong behaviour and a unit test for this is also added.

Fix #531

Author: wayneparrott

lib/time.js

@@ -97,9 +97,9 @@ class Time {
    */
 
   get secondsAndNanoseconds() {
-    let seconds = this._nanoseconds.divide(1e9).toNumber();
-    let nanoseconds = this._nanoseconds.mod(1e9).toNumber();
-    return {seconds, nanoseconds};
+    const seconds = int64.from(this._nanoseconds).divide(1e9).toNumber();
+    const nanoseconds = int64.from(this._nanoseconds).mod(1e9).toNumber();
+    return { seconds, nanoseconds };
   }
 
   /**

test/test-time.js

@@ -148,6 +148,10 @@ describe('rclnodejs Time/Clock testing', function() {
     assert.throws(() => {
       time.add(result);
     }, TypeError);
+
+    let nanos = time._nanoseconds;
+    time.secondsAndNanoseconds;
+    assert.strictEqual(time._nanoseconds, nanos);
   });
 
   it('Test duration functions', function() {