Improvements for more coverage

modules/parser-gen/src/main/scala/playground/parsergen/ParserGen.scala

@@ -6,13 +6,15 @@ import org.polyvariant.treesitter4s.Node
 import smithy4s.Blob
 import smithy4s.Document
 import smithy4s.json.Json
+import treesittersmithy.FieldName
 import treesittersmithy.NodeType
 import treesittersmithy.NodeTypes
 import treesittersmithy.TypeName
 import util.chaining.*
 
 import java.nio.file.Files
 import java.nio.file.Paths
+import scala.annotation.targetName
 import scala.jdk.CollectionConverters.*
 import scala.meta.Dialect
 
@@ -24,10 +26,16 @@ def debugDump(s: String): String =
     ""
 
 extension (tn: TypeName) {
+  @targetName("renderTypeName")
   def render: String = tn.value.smartCapitalize.ident
   def asEnumCase: TypeName = TypeName(tn.value + "Case")
 }
 
+extension (fn: FieldName) {
+  @targetName("renderFieldName")
+  def render: String = fn.value.ident
+}
+
 extension (tpe: NodeType) {
 
   def render: String =
@@ -52,7 +60,7 @@ def renderAdt(tpe: NodeType) = {
         |enum $name {
         |${enumCases.mkString_("\n").indentTrim(2)}
         |
-        |  def asNode: Node = this match {
+        |  def node: Node = this match {
         |${tpe
          .subtypes
          .map { nodeType =>
@@ -75,6 +83,18 @@ def renderAdt(tpe: NodeType) = {
          .mkString_("\n")
          .indentTrim(4)}
         |  }
+        |
+        |  def unapply(node: Node): Boolean = node match {
+        |${tpe
+         .subtypes
+         .map { nodeType =>
+           show"""case node @ ${nodeType
+               .tpe
+               .render}() => true"""
+         }
+         .mkString_("\n")
+         .indentTrim(4)}
+        |  }
         |}
         |
         |/*
@@ -90,12 +110,13 @@ def renderClass(tpe: NodeType) = {
     .fields
     .toList
     .map { (k, fieldType) =>
-      val singleFieldType = fieldType
+      val typeUnion = fieldType
         .types
         .map(tpe => show"${tpe.tpe.render}")
-        .reduceLeft(_ + " | " + _)
+        .reduceLeftOption(_ + " | " + _)
+        .getOrElse(sys.error(s"unexpected empty list of types: $k (in ${tpe.tpe})"))
 
-      val fieldTypeAnnotation = singleFieldType.pipe {
+      val fieldTypeAnnotation = typeUnion.pipe {
         case s if fieldType.multiple => show"List[$s]"
         case s                       => s
       }
@@ -110,9 +131,12 @@ def renderClass(tpe: NodeType) = {
                                          |${cases.mkString("\n").indentTrim(2)}
                                          |}""".stripMargin
         else
-          show"""${singleFieldType}($allFields.head)"""
+          // todo replace head with a stricter "only" check?
+          show"""$allFields.head match {
+                |${cases.mkString("\n").indentTrim(2)}
+                |}""".stripMargin
 
-      show"""def ${k.value}: ${fieldTypeAnnotation} = $fieldValue"""
+      show"""def ${k.render}: ${fieldTypeAnnotation} = $fieldValue"""
     }
 
   show"""// Generated code! Do not modify by hand.
@@ -130,7 +154,7 @@ def renderClass(tpe: NodeType) = {
         |}
         |
         |object $name {
-        |  def unapply(node: Node): scala.Boolean = node.tpe == ${tpe.tpe.value.literal}
+        |  def unapply(node: Node): Boolean = node.tpe == ${tpe.tpe.value.literal}
         |}
         |
         |/*
@@ -156,7 +180,14 @@ def renderClass(tpe: NodeType) = {
 
   types
     .filter(_.named)
-    .map(_.focus(_.fields.each.types).modify(_.filter(_.named)))
+    .map(
+      // only render field types that are named
+      _.focus(_.fields.each.types)
+        .modify(_.filter(_.named))
+        // don't render the field if it has no types
+        .focus(_.fields)
+        .modify(_.filter((_, v) => v.types.nonEmpty))
+    )
     .fproduct(
       _.render
     )

modules/parser/src/main/scala/playground/generated/nodes/Binding.scala

@@ -5,14 +5,18 @@ import org.polyvariant.treesitter4s.Node
 
 case class Binding /* private */(node: Node) extends Node {
 
-  def key: Identifier = Identifier(node.fields("key").head)
-  def value: _Input_node = _Input_node(node.fields("value").head)
+  def key: Identifier = node.fields("key").head match {
+    case node @ Identifier() => Identifier(node)
+  }
+  def value: _Input_node = node.fields("value").head match {
+    case node @ _Input_node() => _Input_node(node)
+  }
 
   export node.*
 }
 
 object Binding {
-  def unapply(node: Node): scala.Boolean = node.tpe == "binding"
+  def unapply(node: Node): Boolean = node.tpe == "binding"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Bindings.scala

@@ -11,7 +11,7 @@ case class Bindings /* private */(node: Node) extends Node {
 }
 
 object Bindings {
-  def unapply(node: Node): scala.Boolean = node.tpe == "bindings"
+  def unapply(node: Node): Boolean = node.tpe == "bindings"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Boolean_.scala

@@ -11,7 +11,7 @@ case class Boolean_ /* private */(node: Node) extends Node {
 }
 
 object Boolean_ {
-  def unapply(node: Node): scala.Boolean = node.tpe == "boolean"
+  def unapply(node: Node): Boolean = node.tpe == "boolean"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Comment.scala

@@ -11,7 +11,7 @@ case class Comment /* private */(node: Node) extends Node {
 }
 
 object Comment {
-  def unapply(node: Node): scala.Boolean = node.tpe == "comment"
+  def unapply(node: Node): Boolean = node.tpe == "comment"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Identifier.scala

@@ -11,7 +11,7 @@ case class Identifier /* private */(node: Node) extends Node {
 }
 
 object Identifier {
-  def unapply(node: Node): scala.Boolean = node.tpe == "identifier"
+  def unapply(node: Node): Boolean = node.tpe == "identifier"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Let_binding.scala

@@ -11,7 +11,7 @@ case class Let_binding /* private */(node: Node) extends Node {
 }
 
 object Let_binding {
-  def unapply(node: Node): scala.Boolean = node.tpe == "let_binding"
+  def unapply(node: Node): Boolean = node.tpe == "let_binding"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/List_.scala

@@ -5,13 +5,15 @@ import org.polyvariant.treesitter4s.Node
 
 case class List_ /* private */(node: Node) extends Node {
 
-  def list_fields: List_fields = List_fields(node.fields("list_fields").head)
+  def list_fields: List_fields = node.fields("list_fields").head match {
+    case node @ List_fields() => List_fields(node)
+  }
 
   export node.*
 }
 
 object List_ {
-  def unapply(node: Node): scala.Boolean = node.tpe == "list"
+  def unapply(node: Node): Boolean = node.tpe == "list"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/List_fields.scala

@@ -11,7 +11,7 @@ case class List_fields /* private */(node: Node) extends Node {
 }
 
 object List_fields {
-  def unapply(node: Node): scala.Boolean = node.tpe == "list_fields"
+  def unapply(node: Node): Boolean = node.tpe == "list_fields"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Null_.scala

@@ -11,7 +11,7 @@ case class Null_ /* private */(node: Node) extends Node {
 }
 
 object Null_ {
-  def unapply(node: Node): scala.Boolean = node.tpe == "null"
+  def unapply(node: Node): Boolean = node.tpe == "null"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Number.scala

@@ -11,7 +11,7 @@ case class Number /* private */(node: Node) extends Node {
 }
 
 object Number {
-  def unapply(node: Node): scala.Boolean = node.tpe == "number"
+  def unapply(node: Node): Boolean = node.tpe == "number"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Operation_call.scala

@@ -5,14 +5,18 @@ import org.polyvariant.treesitter4s.Node
 
 case class Operation_call /* private */(node: Node) extends Node {
 
-  def input: Struct = Struct(node.fields("input").head)
-  def operation_name: Operation_name = Operation_name(node.fields("operation_name").head)
+  def input: Struct = node.fields("input").head match {
+    case node @ Struct() => Struct(node)
+  }
+  def operation_name: Operation_name = node.fields("operation_name").head match {
+    case node @ Operation_name() => Operation_name(node)
+  }
 
   export node.*
 }
 
 object Operation_call {
-  def unapply(node: Node): scala.Boolean = node.tpe == "operation_call"
+  def unapply(node: Node): Boolean = node.tpe == "operation_call"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Operation_name.scala

@@ -8,13 +8,15 @@ case class Operation_name /* private */(node: Node) extends Node {
   def identifier: List[Qualified_identifier] = node.fields("identifier").toList.collect {
     case node @ Qualified_identifier() => Qualified_identifier(node)
   }
-  def name: Identifier = Identifier(node.fields("name").head)
+  def name: Identifier = node.fields("name").head match {
+    case node @ Identifier() => Identifier(node)
+  }
 
   export node.*
 }
 
 object Operation_name {
-  def unapply(node: Node): scala.Boolean = node.tpe == "operation_name"
+  def unapply(node: Node): Boolean = node.tpe == "operation_name"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Qualified_identifier.scala

@@ -5,8 +5,12 @@ import org.polyvariant.treesitter4s.Node
 
 case class Qualified_identifier /* private */(node: Node) extends Node {
 
-  def head: Identifier = Identifier(node.fields("head").head)
-  def selection: Identifier = Identifier(node.fields("selection").head)
+  def head: Identifier = node.fields("head").head match {
+    case node @ Identifier() => Identifier(node)
+  }
+  def selection: Identifier = node.fields("selection").head match {
+    case node @ Identifier() => Identifier(node)
+  }
   def tail: List[Identifier] = node.fields("tail").toList.collect {
     case node @ Identifier() => Identifier(node)
   }
@@ -15,7 +19,7 @@ case class Qualified_identifier /* private */(node: Node) extends Node {
 }
 
 object Qualified_identifier {
-  def unapply(node: Node): scala.Boolean = node.tpe == "qualified_identifier"
+  def unapply(node: Node): Boolean = node.tpe == "qualified_identifier"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Source_file.scala

@@ -5,14 +5,18 @@ import org.polyvariant.treesitter4s.Node
 
 case class Source_file /* private */(node: Node) extends Node {
 
-  def statements: Top_level_statement = Top_level_statement(node.fields("statements").head)
-  def use_clause: Use_clause = Use_clause(node.fields("use_clause").head)
+  def statements: Top_level_statement = node.fields("statements").head match {
+    case node @ Top_level_statement() => Top_level_statement(node)
+  }
+  def use_clause: Use_clause = node.fields("use_clause").head match {
+    case node @ Use_clause() => Use_clause(node)
+  }
 
   export node.*
 }
 
 object Source_file {
-  def unapply(node: Node): scala.Boolean = node.tpe == "source_file"
+  def unapply(node: Node): Boolean = node.tpe == "source_file"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/String_.scala

@@ -11,7 +11,7 @@ case class String_ /* private */(node: Node) extends Node {
 }
 
 object String_ {
-  def unapply(node: Node): scala.Boolean = node.tpe == "string"
+  def unapply(node: Node): Boolean = node.tpe == "string"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Struct.scala

@@ -5,13 +5,15 @@ import org.polyvariant.treesitter4s.Node
 
 case class Struct /* private */(node: Node) extends Node {
 
-  def bindings: Bindings = Bindings(node.fields("bindings").head)
+  def bindings: Bindings = node.fields("bindings").head match {
+    case node @ Bindings() => Bindings(node)
+  }
 
   export node.*
 }
 
 object Struct {
-  def unapply(node: Node): scala.Boolean = node.tpe == "struct"
+  def unapply(node: Node): Boolean = node.tpe == "struct"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Top_level_statement.scala

@@ -11,7 +11,7 @@ case class Top_level_statement /* private */(node: Node) extends Node {
 }
 
 object Top_level_statement {
-  def unapply(node: Node): scala.Boolean = node.tpe == "top_level_statement"
+  def unapply(node: Node): Boolean = node.tpe == "top_level_statement"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Use_clause.scala

@@ -5,13 +5,15 @@ import org.polyvariant.treesitter4s.Node
 
 case class Use_clause /* private */(node: Node) extends Node {
 
-  def identifier: Qualified_identifier = Qualified_identifier(node.fields("identifier").head)
+  def identifier: Qualified_identifier = node.fields("identifier").head match {
+    case node @ Qualified_identifier() => Qualified_identifier(node)
+  }
 
   export node.*
 }
 
 object Use_clause {
-  def unapply(node: Node): scala.Boolean = node.tpe == "use_clause"
+  def unapply(node: Node): Boolean = node.tpe == "use_clause"
 }
 
 /*

modules/parser/src/main/scala/playground/generated/nodes/Whitespace.scala

@@ -11,7 +11,7 @@ case class Whitespace /* private */(node: Node) extends Node {
 }
 
 object Whitespace {
-  def unapply(node: Node): scala.Boolean = node.tpe == "whitespace"
+  def unapply(node: Node): Boolean = node.tpe == "whitespace"
 }
 
 /*