fixed invalid TS call and added test files (#6495)

e581013e3d broke TS generation - please don't use "replace" to refactor function names :)

tests/union_vector/rapunzel.ts

@@ -0,0 +1,63 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+
+
+export class Rapunzel {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+__init(i:number, bb:flatbuffers.ByteBuffer):Rapunzel {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+hairLength():number {
+  return this.bb!.readInt32(this.bb_pos);
+}
+
+mutate_hair_length(value:number):boolean {
+  this.bb!.writeInt32(this.bb_pos + 0, value);
+  return true;
+}
+
+static getFullyQualifiedName():string {
+  return 'Rapunzel';
+}
+
+static sizeOf():number {
+  return 4;
+}
+
+static createRapunzel(builder:flatbuffers.Builder, hair_length: number):flatbuffers.Offset {
+  builder.prep(4, 4);
+  builder.writeInt32(hair_length);
+  return builder.offset();
+}
+
+
+unpack(): RapunzelT {
+  return new RapunzelT(
+    this.hairLength()
+  );
+}
+
+
+unpackTo(_o: RapunzelT): void {
+  _o.hairLength = this.hairLength();
+}
+}
+
+export class RapunzelT {
+constructor(
+  public hairLength: number = 0
+){}
+
+
+pack(builder:flatbuffers.Builder): flatbuffers.Offset {
+  return Rapunzel.createRapunzel(builder,
+    this.hairLength
+  );
+}
+}