Opaque types for WebGL

WebGL types are included in the default lib.d.ts. However, most types are defined as empty interfaces, which means that the compiler doesn't catch many WebGL errors.

Consider the following code:

function foo(gl: WebGLRenderingContext, fbo: WebGLFramebuffer) {
  gl.bindFramebuffer(gl.FRAMEBUFFER, fbo); // Correct call
  gl.bindFramebuffer(gl.FRAMEBUFFER, "abc"); // This should be a compile error!

  fbo = gl.createFramebuffer(); // Correct call
  fbo = new WebGLFramebuffer; // This should be a compile error!
}

• The second parameter of gl.bindFramebuffer should be a WebGLFramebuffer object, but passing a string does not emit a compile error or warning.
• The type WebGLFramebuffer can only be constructed via WebGLRenderingContext.createFramebuffer, calling new throws an error at runtime

Ideally, Typescript would know that WebGLFramebuffer, even though it has no public properties, cannot be constructed or converted to any other type.
I assume that this is not easy to specify with structural typing, but having such opaque types could be useful for other libraries as well (e.g., for returning handles).

If that is not possible, can we find a workaround that at least helps catching the above mentioned bugs?

For reference, here's how the above types are currently defined in lib.d.ts:

interface WebGLFramebuffer extends WebGLObject {
}
declare var WebGLFramebuffer: {
    prototype: WebGLFramebuffer;
    new(): WebGLFramebuffer;
}
interface WebGLRenderingContext {
    bindFramebuffer(target: number, framebuffer: WebGLFramebuffer): void;
    // + many other methods
}

先从 lib.d.ts 中显示的 WebGLFramebuffer 和 WebGLRenderingContext 定义开始，然后跟踪编译器如何处理它们的结构类型和构造函数声明。只有当 TypeScript 具有一种已达成共识的机制或 workaround，能够拒绝无效的 bindFramebuffer 参数和直接构造，并且该行为由适当的编译器测试覆盖时，这个 issue 才算完成。