Restore timestamp conversion behavior to allow ranges outside RFC3339

Related: #890
PiperOrigin-RevId: 844580057

Author: l46kok

common/src/main/java/dev/cel/common/internal/BUILD.bazel

@@ -429,6 +429,7 @@ cel_android_library(
     deps = [
         "//common/annotations",
         "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven//:com_google_guava_guava",
         "@maven_android//:com_google_guava_guava",
         "@maven_android//:com_google_protobuf_protobuf_javalite",
     ],

common/src/main/java/dev/cel/common/internal/ProtoTimeUtils.java

@@ -18,6 +18,7 @@
 import static com.google.common.math.LongMath.checkedMultiply;
 import static com.google.common.math.LongMath.checkedSubtract;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.protobuf.Duration;
@@ -49,12 +50,16 @@
 public final class ProtoTimeUtils {
 
   // Timestamp for "0001-01-01T00:00:00Z"
-  private static final long TIMESTAMP_SECONDS_MIN = -62135596800L;
-
+  @VisibleForTesting
+  static final long TIMESTAMP_SECONDS_MIN = -62135596800L;
   // Timestamp for "9999-12-31T23:59:59Z"
-  private static final long TIMESTAMP_SECONDS_MAX = 253402300799L;
-  private static final long DURATION_SECONDS_MIN = -315576000000L;
-  private static final long DURATION_SECONDS_MAX = 315576000000L;
+  @VisibleForTesting
+  static final long TIMESTAMP_SECONDS_MAX = 253402300799L;
+  @VisibleForTesting
+  static final long DURATION_SECONDS_MIN = -315576000000L;
+  @VisibleForTesting
+  static final long DURATION_SECONDS_MAX = 315576000000L;
+
   private static final int MILLIS_PER_SECOND = 1000;
 
   private static final int NANOS_PER_SECOND = 1000000000;
@@ -344,7 +349,8 @@ public static Timestamp parse(String value) throws ParseException {
       }
     }
     try {
-      return normalizedTimestamp(seconds, nanos);
+      Timestamp timestamp = normalizedTimestamp(seconds, nanos);
+      return checkValid(timestamp);
     } catch (IllegalArgumentException e) {
       ParseException ex =
           new ParseException(
@@ -532,8 +538,7 @@ private static Timestamp normalizedTimestamp(long seconds, int nanos) {
       nanos = nanos + NANOS_PER_SECOND; // no overflow since nanos is negative (and we're adding)
       seconds = checkedSubtract(seconds, 1);
     }
-    Timestamp timestamp = Timestamp.newBuilder().setSeconds(seconds).setNanos(nanos).build();
-    return checkValid(timestamp);
+    return Timestamp.newBuilder().setSeconds(seconds).setNanos(nanos).build();
   }
 
   private static Duration normalizedDuration(long seconds, int nanos) {
@@ -549,8 +554,7 @@ private static Duration normalizedDuration(long seconds, int nanos) {
       nanos -= NANOS_PER_SECOND; // no overflow since nanos is positive (and we're subtracting)
       seconds++; // no overflow since seconds is negative (and we're incrementing)
     }
-    Duration duration = Duration.newBuilder().setSeconds(seconds).setNanos(nanos).build();
-    return checkValid(duration);
+    return Duration.newBuilder().setSeconds(seconds).setNanos(nanos).build();
   }
 
   private static String formatNanos(int nanos) {

common/src/test/java/dev/cel/common/internal/BUILD.bazel

@@ -28,6 +28,7 @@ java_library(
         "//common/internal:errors",
         "//common/internal:proto_equality",
         "//common/internal:proto_message_factory",
+        "//common/internal:proto_time_utils",
         "//common/internal:well_known_proto",
         "//common/src/test/resources:default_instance_message_test_protos_java_proto",
         "//common/src/test/resources:service_conflicting_name_java_proto",

common/src/test/java/dev/cel/common/internal/ProtoTimeUtilsTest.java

@@ -0,0 +1,72 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dev.cel.common.internal;
+
+import static com.google.common.truth.Truth.assertThat;
+import static dev.cel.common.internal.ProtoTimeUtils.DURATION_SECONDS_MAX;
+import static dev.cel.common.internal.ProtoTimeUtils.DURATION_SECONDS_MIN;
+
+import com.google.protobuf.Duration;
+import com.google.protobuf.Timestamp;
+import com.google.testing.junit.testparameterinjector.TestParameterInjector;
+import java.time.Instant;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(TestParameterInjector.class)
+public class ProtoTimeUtilsTest {
+
+  @Test
+  public void toJavaInstant_overRfc3339Range() {
+    Timestamp ts =
+        Timestamp.newBuilder().setSeconds(ProtoTimeUtils.TIMESTAMP_SECONDS_MAX + 1).build();
+
+    Instant instant = ProtoTimeUtils.toJavaInstant(ts);
+
+    assertThat(instant).isEqualTo(Instant.ofEpochSecond(ProtoTimeUtils.TIMESTAMP_SECONDS_MAX + 1));
+  }
+
+  @Test
+  public void toJavaInstant_underRfc3339Range() {
+    Timestamp ts =
+        Timestamp.newBuilder().setSeconds(ProtoTimeUtils.TIMESTAMP_SECONDS_MIN - 1).build();
+
+    Instant instant = ProtoTimeUtils.toJavaInstant(ts);
+
+    assertThat(instant).isEqualTo(Instant.ofEpochSecond(ProtoTimeUtils.TIMESTAMP_SECONDS_MIN - 1));
+  }
+
+  @Test
+  public void toJavaDuration_overRfc3339Range() {
+    Duration d = Duration.newBuilder()
+        .setSeconds(DURATION_SECONDS_MAX + 1)
+        .build();
+
+    java.time.Duration duration = ProtoTimeUtils.toJavaDuration(d);
+
+    assertThat(duration).isEqualTo(java.time.Duration.ofSeconds(DURATION_SECONDS_MAX + 1));
+  }
+
+  @Test
+  public void toJavaDuration_underRfc3339Range() {
+    Duration d = Duration.newBuilder()
+        .setSeconds(DURATION_SECONDS_MIN - 1)
+        .build();
+
+    java.time.Duration duration = ProtoTimeUtils.toJavaDuration(d);
+
+    assertThat(duration).isEqualTo(java.time.Duration.ofSeconds(DURATION_SECONDS_MIN - 1));
+  }
+}