[keichi]

Problem

addAliasedCode emitted new constructorFn(), which resolves to the constructorFn parameter of the top-level compiled function (the top-level parser's constructor), not the constructor set via create() on the aliased parser.

Repro

class Foo { constructor() { this.isFoo = true; } }
Parser.start().create(Foo).uint8("v").namely("WithFoo");
new Parser().nest("n", { type: "WithFoo" }).parse(Buffer.from([1]));
// TypeError: constructorFn is not a constructor

If the top-level parser has its own create(Bar), the nested alias objects are wrongly constructed as Bar.

Fix

Reference the aliased parser's constructor through the imports mechanism: new ${ctx.addImport(this.constructorFn)}(). Added a regression test covering a plain top-level parser, a top-level parser with a different constructor, and a top-level aliased parser.