Timestamp helper fix, Duration helper cleanup.

- The Timestamp proto does not allow for negative nanos fields, so the seconds
  must be shifted and a positive nanos then applied.
- Tweak the helpers on Duration to make it clear there is no "base" time
  involved.
- Update the unittests for duration and timestamp to cover positive and
  negative NSTimeIntervals and what their impact is on the protos.

1 files changed, 109 insertions, 53 deletions

diff --git a/objectivec/Tests/GPBWellKnownTypesTest.m b/objectivec/Tests/GPBWellKnownTypesTest.m
index 041841dd..592d5afd 100644
--- a/objectivec/Tests/GPBWellKnownTypesTest.m
+++ b/objectivec/Tests/GPBWellKnownTypesTest.m
@@ -32,11 +32,9 @@
 
 #import <XCTest/XCTest.h>
 
+#import "GPBTestUtilities.h"
 #import "google/protobuf/AnyTest.pbobjc.h"
 
-// A basically random interval into the future for testing with.
-static const NSTimeInterval kFutureOffsetInterval = 15000;
-
 // Nanosecond time accuracy
 static const NSTimeInterval kTimeAccuracy = 1e-9;
 
@@ -46,59 +44,117 @@ static const NSTimeInterval kTimeAccuracy = 1e-9;
 @implementation WellKnownTypesTest
 
 - (void)testTimeStamp {
-  // Test Creation.
-  NSDate *date = [NSDate date];
-  GPBTimestamp *timeStamp = [[GPBTimestamp alloc] initWithDate:date];
-  NSDate *timeStampDate = timeStamp.date;
-
-  // Comparing timeIntervals instead of directly comparing dates because date
-  // equality requires the time intervals to be exactly the same, and the
-  // timeintervals go through a bit of floating point error as they are
-  // converted back and forth from the internal representation.
-  XCTAssertEqualWithAccuracy(date.timeIntervalSince1970,
-                             timeStampDate.timeIntervalSince1970,
-                             kTimeAccuracy);
-
-  NSTimeInterval time = [date timeIntervalSince1970];
-  GPBTimestamp *timeStamp2 =
-      [[GPBTimestamp alloc] initWithTimeIntervalSince1970:time];
-  NSTimeInterval durationTime = timeStamp2.timeIntervalSince1970;
-  XCTAssertEqualWithAccuracy(time, durationTime, kTimeAccuracy);
-  [timeStamp release];
-
-  // Test Mutation.
-  date = [NSDate dateWithTimeIntervalSinceNow:kFutureOffsetInterval];
-  timeStamp2.date = date;
-  timeStampDate = timeStamp2.date;
-  XCTAssertEqualWithAccuracy(date.timeIntervalSince1970,
-                             timeStampDate.timeIntervalSince1970,
-                             kTimeAccuracy);
-
-  time = date.timeIntervalSince1970;
-  timeStamp2.timeIntervalSince1970 = time;
-  durationTime = timeStamp2.timeIntervalSince1970;
-  XCTAssertEqualWithAccuracy(time, durationTime, kTimeAccuracy);
-  [timeStamp2 release];
+  // Test negative and positive values.
+  NSTimeInterval values[] = {
+      -428027599.483999967, -1234567.0, -0.5, 0, 0.75, 54321.0, 2468086,483999967
+  };
+  for (size_t i = 0; i < GPBARRAYSIZE(values); ++i) {
+    NSTimeInterval value = values[i];
+
+    // Test Creation - date.
+    NSDate *date = [NSDate dateWithTimeIntervalSince1970:value];
+    GPBTimestamp *timeStamp = [[GPBTimestamp alloc] initWithDate:date];
+
+    XCTAssertGreaterThanOrEqual(timeStamp.nanos, 0,
+                                @"Offset %f - Date: %@", (double)value, date);
+    XCTAssertLessThan(timeStamp.nanos, 1e9,
+                      @"Offset %f - Date: %@", (double)value, date);
+
+    // Comparing timeIntervals instead of directly comparing dates because date
+    // equality requires the time intervals to be exactly the same, and the
+    // timeintervals go through a bit of floating point error as they are
+    // converted back and forth from the internal representation.
+    XCTAssertEqualWithAccuracy(value, timeStamp.date.timeIntervalSince1970,
+                               kTimeAccuracy,
+                               @"Offset %f - Date: %@", (double)value, date);
+    [timeStamp release];
+
+    // Test Creation - timeIntervalSince1970.
+    timeStamp = [[GPBTimestamp alloc] initWithTimeIntervalSince1970:value];
+
+    XCTAssertGreaterThanOrEqual(timeStamp.nanos, 0,
+                                @"Offset %f - Date: %@", (double)value, date);
+    XCTAssertLessThan(timeStamp.nanos, 1e9,
+                      @"Offset %f - Date: %@", (double)value, date);
+
+    XCTAssertEqualWithAccuracy(value, timeStamp.timeIntervalSince1970,
+                               kTimeAccuracy,
+                               @"Offset %f - Date: %@", (double)value, date);
+    [timeStamp release];
+
+    // Test Mutation - date.
+    timeStamp = [[GPBTimestamp alloc] init];
+    timeStamp.date = date;
+
+    XCTAssertGreaterThanOrEqual(timeStamp.nanos, 0,
+                                @"Offset %f - Date: %@", (double)value, date);
+    XCTAssertLessThan(timeStamp.nanos, 1e9,
+                      @"Offset %f - Date: %@", (double)value, date);
+
+    XCTAssertEqualWithAccuracy(value, timeStamp.date.timeIntervalSince1970,
+                               kTimeAccuracy,
+                               @"Offset %f - Date: %@", (double)value, date);
+    [timeStamp release];
+
+    // Test Mutation - timeIntervalSince1970.
+    timeStamp = [[GPBTimestamp alloc] init];
+    timeStamp.timeIntervalSince1970 = value;
+
+    XCTAssertGreaterThanOrEqual(timeStamp.nanos, 0,
+                                @"Offset %f - Date: %@", (double)value, date);
+    XCTAssertLessThan(timeStamp.nanos, 1e9,
+                      @"Offset %f - Date: %@", (double)value, date);
+
+    XCTAssertEqualWithAccuracy(value, timeStamp.date.timeIntervalSince1970,
+                               kTimeAccuracy,
+                               @"Offset %f - Date: %@", (double)value, date);
+
+    [timeStamp release];
+  }
 }
 
 - (void)testDuration {
-  // Test Creation.
-  NSTimeInterval time = [[NSDate date] timeIntervalSince1970];
-  GPBDuration *duration =
-      [[GPBDuration alloc] initWithTimeIntervalSince1970:time];
-  NSTimeInterval durationTime = duration.timeIntervalSince1970;
-  XCTAssertEqualWithAccuracy(time, durationTime, kTimeAccuracy);
-  [duration release];
-
-  // Test Mutation.
-  GPBDuration *duration2 =
-      [[GPBDuration alloc] initWithTimeIntervalSince1970:time];
-  NSDate *date = [NSDate dateWithTimeIntervalSinceNow:kFutureOffsetInterval];
-  time = date.timeIntervalSince1970;
-  duration2.timeIntervalSince1970 = time;
-  durationTime = duration2.timeIntervalSince1970;
-  XCTAssertEqualWithAccuracy(time, durationTime, kTimeAccuracy);
-  [duration2 release];
+  // Test negative and positive values.
+  NSTimeInterval values[] = { -1000.0001, -500.0, -0.5, 0, 0.75, 1000.0, 2000.0002 };
+  for (size_t i = 0; i < GPBARRAYSIZE(values); ++i) {
+    NSTimeInterval value = values[i];
+
+    // Test Creation.
+    GPBDuration *duration =
+        [[GPBDuration alloc] initWithTimeInterval:value];
+    XCTAssertEqualWithAccuracy(value, duration.timeInterval, kTimeAccuracy,
+                               @"For interval %f", (double)value);
+    if (value > 0) {
+      XCTAssertGreaterThanOrEqual(duration.seconds, 0,
+                                  @"For interval %f", (double)value);
+      XCTAssertGreaterThanOrEqual(duration.nanos, 0,
+                                  @"For interval %f", (double)value);
+    } else {
+      XCTAssertLessThanOrEqual(duration.seconds, 0,
+                               @"For interval %f", (double)value);
+      XCTAssertLessThanOrEqual(duration.nanos, 0,
+                               @"For interval %f", (double)value);
+    }
+    [duration release];
+
+    // Test Mutation.
+    duration = [[GPBDuration alloc] init];
+    duration.timeInterval = value;
+    XCTAssertEqualWithAccuracy(value, duration.timeInterval, kTimeAccuracy,
+                               @"For interval %f", (double)value);
+    if (value > 0) {
+      XCTAssertGreaterThanOrEqual(duration.seconds, 0,
+                                  @"For interval %f", (double)value);
+      XCTAssertGreaterThanOrEqual(duration.nanos, 0,
+                                  @"For interval %f", (double)value);
+    } else {
+      XCTAssertLessThanOrEqual(duration.seconds, 0,
+                               @"For interval %f", (double)value);
+      XCTAssertLessThanOrEqual(duration.nanos, 0,
+                               @"For interval %f", (double)value);
+    }
+    [duration release];
+  }
 }
 
 - (void)testAnyHelpers {