convert Temporal.PlainTime asTime(), and test

Author: wirthi

graal-js/src/com.oracle.truffle.js.test/src/com/oracle/truffle/js/test/interop/TemporalInteropToJavaTest.java

@@ -116,10 +116,17 @@ public void testInstant() {
     // public void testPlainDate() {
     // }
 
-    // TODO
-    // @Test
-    // public void testPlainTime() {
-    // }
+    @Test
+    public void testPlainTime() {
+        try (Context ctx = getJSContext()) {
+            Value val = ctx.eval(ID, "new Temporal.PlainTime(12, 34, 56, 987, 654, 321);");
+            LocalTime lt = val.asTime();
+            Assert.assertEquals(12, lt.getHour());
+            Assert.assertEquals(34, lt.getMinute());
+            Assert.assertEquals(56, lt.getSecond());
+            Assert.assertEquals(987_654_321L, lt.getNano());
+        }
+    }
 
     // TODO
     // @Test

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/builtins/temporal/JSTemporalPlainTimeObject.java

@@ -40,10 +40,17 @@
  */
 package com.oracle.truffle.js.runtime.builtins.temporal;
 
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.library.ExportLibrary;
+import com.oracle.truffle.api.library.ExportMessage;
 import com.oracle.truffle.api.object.Shape;
 import com.oracle.truffle.js.runtime.objects.JSDynamicObject;
 import com.oracle.truffle.js.runtime.objects.JSNonProxyObject;
 
+import java.time.LocalTime;
+
+@ExportLibrary(InteropLibrary.class)
 public class JSTemporalPlainTimeObject extends JSNonProxyObject implements TemporalTime {
 
     // all values guaranteed to fit into int
@@ -102,4 +109,18 @@ public int getNanosecond() {
     public JSDynamicObject getCalendar() {
         return calendar;
     }
+
+    @ExportMessage
+    @SuppressWarnings("static-method")
+    final boolean isTime() {
+        return true;
+    }
+
+    @ExportMessage
+    @TruffleBoundary
+    final LocalTime asTime() {
+        int ns = millisecond * 1_000_000 + microsecond * 1_000 + nanosecond;
+        LocalTime lt = LocalTime.of(hour, minute, second, ns);
+        return lt;
+    }
 }