Merge pull request #3130 from daboe01/fixed-NSDateFormatter-unable-to-parse-dates-in-Javascript-Date.toISOString-format

fixed: NSDateFormatter was unable to parse dates in Javascript Date.toISOString format

Foundation/CPDateFormatter.j

@@ -1291,6 +1291,18 @@ var _separatorsCharacterSet = nil;
     if (!aString)
         return [[CPDate alloc] initWithTimeIntervalSinceReferenceDate:-31622400];
 
+    // Special case for ISO8601 format, which is poorly handled by the generic parser.
+    if (aFormat === @"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'") {
+        var d = new Date(aString);
+        if (d && !isNaN(d.getTime())) {
+            // The native JS Date object handles ISO 8601 strings correctly (as UTC).
+            // We can create a CPDate directly from the resulting timestamp.
+            var kCFAbsoluteTimeIntervalSince1970 = 978307200.0;
+            var interval = (d.getTime() / 1000.0) - kCFAbsoluteTimeIntervalSince1970;
+            return [CPDate dateWithTimeIntervalSinceReferenceDate:interval];
+        }
+    }
+
     if (aFormat == nil)
         return nil;
 

Tests/Foundation/CPDateFormatterTest.j

@@ -1245,6 +1245,41 @@
     [self assert:result equals:nil];
 }
 
+- (void)testDateFromStringISO8601
+{
+    // This test verifies the fix for issue #2537.
+    // The parser should correctly handle the ISO 8601 format produced by Date.toISOString().
+    var dateFormatter = [[CPDateFormatter alloc] init];
+    [dateFormatter setLocale:[[CPLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
+    [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"];
+
+    // Test with a fixed date string.
+    var fixedISOString = @"2017-03-31T16:40:15.768Z";
+    var parsedFixedDate = [dateFormatter dateFromString:fixedISOString];
+
+    // Create the expected date using a known-good method (JS Date parsing) to avoid relying on
+    // the code under test. We create it from a time interval, which supports millisecond precision.
+    var expectedTimestamp = new Date(fixedISOString).getTime() / 1000.0;
+    var expectedFixedDate = [CPDate dateWithTimeIntervalSince1970:expectedTimestamp];
+
+    // Now assert that the formatter produced the same date.
+    // isEqualToDate: compares the underlying time interval, which is what we want.
+    [self assertTrue:[parsedFixedDate isEqualToDate:expectedFixedDate] message:@"DateFormatter should correctly parse a fixed ISO 8601 string."];
+
+    // Test with a dynamically generated date string.
+    var liveJSDate = new Date();
+    var liveISOString = liveJSDate.toISOString();
+
+    var parsedLiveDate = [dateFormatter dateFromString:liveISOString];
+
+    // The fix converts from a JS Date, so we can compare time intervals for accuracy.
+    var liveJSDateTime = liveJSDate.getTime();
+    var parsedLiveDateTime = [parsedLiveDate timeIntervalSince1970] * 1000;
+
+    // We allow a small tolerance for floating point rounding.
+    [self assertTrue:Math.abs(liveJSDateTime - parsedLiveDateTime) < 1.0 message:@"DateFormatter should correctly parse a dynamically generated ISO 8601 string."];
+}
+
 - (void)testGetObjectValueAcceptsNilErrorDescription
 {
     var date = nil,