Merge pull request #25 from bpholt/DateTimeFormatter

add support for DateTimeFormatter literals

Author: bpholt

build.sbt

@@ -9,6 +9,7 @@ lazy val V = new {
   val SCALA_3 = "3.0.2"
   val Scalas = Seq(SCALA_2_13, SCALA_2_12, SCALA_3)
   val literally = "1.0.2"
+  val munit = "0.7.29"
 }
 
 inThisBuild(List(
@@ -55,7 +56,8 @@ lazy val `java-time-literals` = crossProject(JSPlatform, JVMPlatform)
       scalaReflect ++
         Seq(
           "org.typelevel" %% "literally" % V.literally,
-          "org.scalameta" %% "munit" % "0.7.29" % Test,
+          "org.scalameta" %% "munit" % V.munit % Test,
+          "org.scalameta" %% "munit-scalacheck" % V.munit % Test,
         )
     },
     Compile / unmanagedSourceDirectories ++= { // needed until https://github.com/portable-scala/sbt-crossproject/issues/70 is fixed

core/shared/src/main/scala-2/dev/holt/javatime/literals.scala

@@ -3,6 +3,7 @@ package dev.holt.javatime
 import org.typelevel.literally.Literally
 
 import java.time._
+import java.time.format.DateTimeFormatter
 import scala.reflect.macros.blackbox
 import scala.util.{Failure, Success, Try}
 
@@ -274,4 +275,23 @@ object literals {
     }
   }
 
+  implicit class dateTimeFormatter(val sc: StringContext) extends AnyVal {
+    def dateTimeFormatter(args: Any*): DateTimeFormatter = macro DateTimeFormatterLiteral.make
+  }
+
+  object DateTimeFormatterLiteral extends Literally[DateTimeFormatter] {
+    def make(c: blackbox.Context)
+            (args: c.Expr[Any]*): c.Expr[DateTimeFormatter] = apply(c)(args: _*)
+
+    override def validate(c: DateTimeFormatterLiteral.Context)
+                         (s: String): Either[String, c.Expr[DateTimeFormatter]] = {
+      import c.universe.{Try => _, _}
+
+      Try(DateTimeFormatter.ofPattern(s)) match {
+        case Failure(ex) => Left(ex.getMessage)
+        case Success(_) => Right(c.Expr(q"java.time.format.DateTimeFormatter.ofPattern($s)"))
+      }
+    }
+  }
+
 }

core/shared/src/main/scala-3/dev.holt.javatime/literals.scala

@@ -3,6 +3,7 @@ package dev.holt.javatime
 import org.typelevel.literally.Literally
 
 import java.time._
+import java.time.format.DateTimeFormatter
 import scala.util.{Failure, Success, Try}
 
 //noinspection ScalaUnusedSymbol
@@ -22,6 +23,7 @@ object literals {
     inline def zonedDateTime(args: Any*): ZonedDateTime = ${ZonedDateTimeLiteral('ctx, 'args)}
     inline def zoneId(args: Any*): ZoneId = ${ZoneIdLiteral('ctx, 'args)}
     inline def zoneOffset(args: Any*): ZoneOffset = ${ZoneOffsetLiteral('ctx, 'args)}
+    inline def dateTimeFormatter(args: Any*): DateTimeFormatter = ${DateTimeFormatterLiteral('ctx, 'args)}
   }
 
   object DurationLiteral extends Literally[Duration] {
@@ -136,4 +138,12 @@ object literals {
     }
   }
 
+  object DateTimeFormatterLiteral extends Literally[DateTimeFormatter] {
+    override def validate(s: String)(using Quotes) =
+    Try(DateTimeFormatter.ofPattern(s)) match {
+      case Failure(ex) => Left(ex.getMessage)
+      case Success(_) => Right('{java.time.format.DateTimeFormatter.ofPattern(${Expr(s)})})
+    }
+  }
+
 }

core/shared/src/test/scala/dev/holt/javatime/JavaTimeSuite.scala

@@ -1,11 +1,13 @@
 package dev.holt.javatime
 
 import dev.holt.javatime.literals._
-import munit.FunSuite
+import munit.ScalaCheckSuite
+import org.scalacheck.Prop.forAll
 
 import java.time._
+import java.time.format.DateTimeFormatter
 
-class JavaTimeSuite extends FunSuite {
+class JavaTimeSuite extends ScalaCheckSuite {
   test("Duration interpolation should work like runtime parsing") {
     val expected = Duration.parse("PT20.345S")
     val output = duration"PT20.345S"
@@ -103,4 +105,14 @@ class JavaTimeSuite extends FunSuite {
 
     assertEquals(expected, output)
   }
+
+  test("DateTimeFormatter interpolation should work like runtime parsing") {
+    forAll { (timestamp: LocalDateTime) =>
+      val expected = DateTimeFormatter.ofPattern("yyyy").format(timestamp)
+      val output = dateTimeFormatter"yyyy".format(timestamp)
+
+      assertEquals(expected, output)
+    }
+  }
+
 }