start work on #166

[Rich-Harris]

This starts to address #166, by creating a Builder class (naming subject to yak-shaving) that gets passed to adapters. The idea is that rather than adapters making assumptions about file structure and having to import various helper functions from app-utils, everything is co-located in a way that reduces code duplication etc.

So adapter-static goes from this...

import { RouteManifest } from '@sveltejs/app-utils';
import { copy } from '@sveltejs/app-utils/files';
import { prerender } from '@sveltejs/app-utils/renderer';
import { Logger } from '@sveltejs/app-utils/renderer/prerender';

module.exports = async function adapter({
  dir,
  manifest,
  log
}: {
  dir: string;
  manifest: RouteManifest;
  log: Logger;
}) {
  const out = 'build'; // TODO implement adapter options

  copy('static', out);
  copy(`${dir}/client`, `${out}/_app`);

  prerender({
    force: true,
    dir,
    out,
    manifest,
    log
  });
};

...to this:

module.exports = async function adapter(builder) {
  builder.copy_static_files('build');
  builder.copy_generated_files('build/_app');

  builder.prerender({
    force: true,
    dest: 'build'
  });
};

Not pictured: a way for the adapter to verify that the builder API is the version that it expects (e.g. builder.check_version('^1.0.0'), which would throw if the version of @sveltejs/kit that provided the builder was at version 2.0.0 or above).

My progress has been somewhat hampered by TypeScript errors that are preventing me from actually writing the PR.

[benmccann]

FYI, this is giving me Usage of undeclared private name, which is probably what your issue is

[Rich-Harris]

closing in favour of #180