util/util-core: Fix conversions to units from Int in Scala3

This fixes lost source-compatibility for unit conversions from Int values in Scala3. As discussed in #295 I extracted/adapted this from #290 (previous discussion). Previously something like 1.toInt.second did compile in Scala2 (with default settings) but didn't in Scala3. I added forwarders for all units which use Long as base, as that seemed reasonable and safe. I didn't add an implicit conversion from Float to Double because floating-point types are dumb and I don't trust the conversion to be lossless in all cases. Signed-off-by: Yufan Gong <[email protected]> Differential Revision: https://phabricator.twitter.biz/D759923
twitter · Oct 13, 2021 · ad8b22b · ad8b22b
1 parent e550817
commit ad8b22b
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Showing 6 changed files with 60 additions and 2 deletions.
diff --git a/util-core/src/main/scala/com/twitter/conversions/DurationOps.scala b/util-core/src/main/scala/com/twitter/conversions/DurationOps.scala
@@ -2,6 +2,7 @@ package com.twitter.conversions
 
 import com.twitter.util.Duration
 import java.util.concurrent.TimeUnit
+import scala.language.implicitConversions
 
 /**
  * Implicits for writing readable [[com.twitter.util.Duration]]s.
@@ -37,4 +38,15 @@ object DurationOps {
     def day: Duration = days
   }
 
+  /**
+   * Forwarder for Int, as Scala 3.0 doesn't seem to do the implicit conversion to Long anymore.
+   * This is not a bug, as Scala 2.13 already had a flag ("-Ywarn-implicit-widening") to turn on warnings/errors
+   * for that.
+   *
+   * The implicit conversion from Int to Long here doesn't lose precision and keeps backwards source compatibliity
+   * with previous releases.
+   */
+  implicit def richDurationFromInt(numNanos: Int): RichDuration =
+    new RichDuration(numNanos.toLong)
+
 }
diff --git a/util-core/src/main/scala/com/twitter/conversions/StorageUnitOps.scala b/util-core/src/main/scala/com/twitter/conversions/StorageUnitOps.scala
@@ -2,6 +2,8 @@ package com.twitter.conversions
 
 import com.twitter.util.StorageUnit
 
+import scala.language.implicitConversions
+
 /**
  * Implicits for writing readable [[com.twitter.util.StorageUnit]]s.
  *
@@ -34,4 +36,15 @@ object StorageUnitOps {
     def million: Long = numBytes * 1000 * 1000
     def billion: Long = numBytes * 1000 * 1000 * 1000
   }
+
+  /**
+   * Forwarder for Int, as Scala 3.0 doesn't seem to do the implicit conversion to Long anymore.
+   * This is not a bug, as Scala 2.13 already had a flag ("-Ywarn-implicit-widening") to turn on warnings/errors
+   * for that.
+   *
+   * The implicit conversion from Int to Long here doesn't lose precision and keeps backwards source compatibliity
+   * with previous releases.
+   */
+  implicit def richStorageUnitFromInt(numBytes: Int): RichStorageUnit =
+    new RichStorageUnit(numBytes.toLong)
 }
diff --git a/util-core/src/main/scala/com/twitter/conversions/U64Ops.scala b/util-core/src/main/scala/com/twitter/conversions/U64Ops.scala
@@ -1,5 +1,7 @@
 package com.twitter.conversions
 
+import scala.language.implicitConversions
+
 object U64Ops {
 
   /**
@@ -19,4 +21,15 @@ object U64Ops {
     def toU64HexString: String = "%016x".format(self)
   }
 
+  /**
+   * Forwarder for Int, as Scala 3.0 doesn't seem to do the implicit conversion to Long anymore.
+   * This is not a bug, as Scala 2.13 already had a flag ("-Ywarn-implicit-widening") to turn on warnings/errors
+   * for that.
+   *
+   * The implicit conversion from Int to Long here doesn't lose precision and keeps backwards source compatibliity
+   * with previous releases.
+   */
+  implicit def richU64LongFromInt(self: Int): RichU64Long =
+    new RichU64Long(self.toLong)
+
 }
diff --git a/util-core/src/test/scala/com/twitter/conversions/DurationOpsTest.scala b/util-core/src/test/scala/com/twitter/conversions/DurationOpsTest.scala
@@ -3,8 +3,9 @@ package com.twitter.conversions
 import com.twitter.util.Duration
 import com.twitter.conversions.DurationOps._
 import org.scalatest.funsuite.AnyFunSuite
+import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
 
-class DurationOpsTest extends AnyFunSuite {
+class DurationOpsTest extends AnyFunSuite with ScalaCheckPropertyChecks {
   test("converts Duration.Zero") {
     assert(0.seconds eq Duration.Zero)
     assert(0.milliseconds eq Duration.Zero)
@@ -17,4 +18,10 @@ class DurationOpsTest extends AnyFunSuite {
     assert(100L.nanoseconds == Duration.fromNanoseconds(100L))
   }
 
+  test("conversion works for Int values") {
+    forAll { (intValue: Int) =>
+      assert(intValue.seconds == intValue.toLong.seconds)
+    }
+  }
+
 }
diff --git a/util-core/src/test/scala/com/twitter/conversions/StorageUnitOpsTest.scala b/util-core/src/test/scala/com/twitter/conversions/StorageUnitOpsTest.scala
@@ -3,8 +3,9 @@ package com.twitter.conversions
 import com.twitter.util.StorageUnit
 import com.twitter.conversions.StorageUnitOps._
 import org.scalatest.funsuite.AnyFunSuite
+import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
 
-class StorageUnitOpsTest extends AnyFunSuite {
+class StorageUnitOpsTest extends AnyFunSuite with ScalaCheckPropertyChecks {
 
   test("converts") {
     assert(StorageUnit.fromBytes(1) == 1.byte)
@@ -26,4 +27,10 @@ class StorageUnitOpsTest extends AnyFunSuite {
     assert(StorageUnit.fromPetabytes(7) == 7.petabytes)
   }
 
+  test("conversion works for Int values") {
+    forAll { (intValue: Int) =>
+      assert(intValue.bytes == intValue.toLong.bytes)
+    }
+  }
+
 }
diff --git a/util-core/src/test/scala/com/twitter/conversions/U64OpsTest.scala b/util-core/src/test/scala/com/twitter/conversions/U64OpsTest.scala
@@ -16,4 +16,10 @@ class U64OpsTest extends AnyFunSuite with ScalaCheckDrivenPropertyChecks {
       assert(s.toU64Long == java.lang.Long.parseUnsignedLong(s, 16))
     }
   }
+
+  test("conversion works for Int values") {
+    forAll { (intValue: Int) =>
+      assert(intValue.toU64HexString == intValue.toLong.toU64HexString)
+    }
+  }
 }