internal/lsp/source: respond with the underlying type to Type Definition requests for composite types

internal/lsp/source/identifier.go

@@ -323,6 +323,12 @@ func typeToObject(typ types.Type) types.Object {
 		return typ.Obj()
 	case *types.Pointer:
 		return typeToObject(typ.Elem())
+	case *types.Array:
+		return typeToObject(typ.Elem())
+	case *types.Slice:
+		return typeToObject(typ.Elem())
+	case *types.Chan:
+		return typeToObject(typ.Elem())
 	default:
 		return nil
 	}

internal/lsp/testdata/summary.txt.golden

@@ -16,7 +16,7 @@ SemanticTokenCount = 3
 SuggestedFixCount = 40
 FunctionExtractionCount = 13
 DefinitionsCount = 90
-TypeDefinitionsCount = 2
+TypeDefinitionsCount = 10
 HighlightsCount = 69
 ReferencesCount = 25
 RenamesCount = 33

internal/lsp/testdata/typdef/typdef.go

@@ -0,0 +1,38 @@
+package typdef
+
+type Struct struct { //@item(Struct, "Struct", "struct{...}", "struct")
+	Field string
+}
+
+type Int int //@item(Int, "Int", "int", "type")
+
+func _() {
+	var (
+		value Struct
+		point *Struct
+	)
+	_ = value //@typdef("value", Struct)
+	_ = point //@typdef("point", Struct)
+
+	var (
+		array   [3]Struct
+		slice   []Struct
+		ch      chan Struct
+		complex [3]chan *[5][]Int
+	)
+	_ = array   //@typdef("array", Struct)
+	_ = slice   //@typdef("slice", Struct)
+	_ = ch      //@typdef("ch", Struct)
+	_ = complex //@typdef("complex", Int)
+
+	var s struct {
+		x struct {
+			xx struct {
+				field1 []Struct
+				field2 []Int
+			}
+		}
+	}
+	s.x.xx.field1 //@typdef("field1", Struct)
+	s.x.xx.field2 //@typdef("field2", Int)
+}