emptyness check for texttree

Author: pshirshov

fundamentals/fundamentals-platform/src/main/scala/izumi/fundamentals/platform/strings/TextTree.scala

@@ -67,6 +67,19 @@ object TextTree {
       }
     }
 
+    def isEmpty: Boolean = {
+      target match {
+        case _: ValueNode[T] => false
+        case s: StringNode => s.value.isEmpty
+        case s: Shift[T] => s.nested.isEmpty
+        case t: Trim[T] => t.nested.isEmpty
+        case n: Node[T] =>
+          n.chunks.forall(_.isEmpty)
+      }
+    }
+
+    def nonEmpty: Boolean = !isEmpty
+
     def flatten: TextTree[T] = {
       target match {
         case v: ValueNode[T] => Node(NEList(v))

fundamentals/fundamentals-platform/src/test/scala/izumi/fundamentals/platform/TextTreeTest.scala

@@ -99,6 +99,17 @@ class TextTreeTest extends AnyWordSpec {
         accept(t5)
       }
     }
+
+    "support emptiness check" in {
+      val q1 = q""
+      val q2 = q"$q1"
+      val q3 = q"x$q1"
+
+      assert(q1.isEmpty)
+      assert(q2.isEmpty)
+      assert(q3.nonEmpty)
+
+    }
   }
 }