Describe the bug

Danger's built-in transpiler for Typescript produces syntax errors when it tries to build some code we import in dangerfile.ts. This bug report is not about danger's typescript transpiler. It's about struggling to find a work-around to a bug in danger's traspiler compiler.

Because Danger's built-in transpiler can't run our dangerfile, we want to use our standard TS_NODE_PROJECT="tsconfig.tsnode.json" node -r ts-node/register/transpile-only workflow with danger.
However, even when setting DANGER_DISABLE_TRANSPILATION=true, danger still doesn't pick up the custom require plugins registered by ts-node.

This is the command I'm running:

DEBUG=danger:* \
DANGER_DISABLE_TRANSPILATION=true \
  TS_NODE_PROJECT=tsconfig.tsnode.json \
  NODE_OPTIONS="-r ts-node/register/transpile-only" \
  node node_modules/.bin/danger local --dangerfile src/dangerfile.ts

It outputs as you'd expect for a .ts file run through danger without transpilation:

Unable to evaluate the Dangerfile
 src/dangerfile.ts:1
import { StatsWithChunkGroups } from "./cli/statsComparison"
^^^^^^

SyntaxError: Cannot use import statement outside a module
    at wrapSafe (internal/modules/cjs/loader.js:1053:16)
    at Module._compile (internal/modules/cjs/loader.js:1101:27)
    at Object.requireFromString [as default] (/Users/jitl/src/notion/node_modules/require-from-string/index.js:28:4)
    at Object.<anonymous> (/Users/jitl/src/notion/node_modules/danger/source/runner/runners/inline.ts:103:38)
    at step (/Users/jitl/src/notion/node_modules/danger/distribution/runner/runners/inline.js:32:23)
    at Object.next (/Users/jitl/src/notion/node_modules/danger/distribution/runner/runners/inline.js:13:53)
    at /Users/jitl/src/notion/node_modules/danger/distribution/runner/runners/inline.js:7:71
    at new Promise (<anonymous>)
    at __awaiter (/Users/jitl/src/notion/node_modules/danger/distribution/runner/runners/inline.js:3:12)
    at Object.exports.runDangerfileEnvironment (/Users/jitl/src/notion/node_modules/danger/source/runner/runners/inline.ts:62:75)

I suspect this is happening because danger overrides require.extensions even when transpilation is supposed to be disabled here:

To Reproduce
Steps to reproduce the behavior:

1. Install danger and ts-node.
2. Write a dangerfile.ts file that does some imports
3. Try the above command pointing to your dangerfile.

Expected behavior
Danger should respect already-register require plugins when transpilation is disabled. I would expect the command posted to work without syntax errors.

Additional context

To work around both this problem, and the original problem with Danger's typescript compiler producing syntax errors, I've decided to transpile dangerfile.ts using tsc as part of our normal build process. In that case, a different work-around is needed to avoid the transpiled typescript from erroring out due to importing the dummy danger node module at runtime. Here's the code snippet I'm employing:

// src/dangerfile.ts
import { StatsWithChunkGroups } from "./cli/statsComparison"

/**
 * We would like to write this code:
 *
 *   import { danger, fail, schedule, message, warn } from "./danger"
 *
 * However, that would make us rely on Danger's very basic internal transpiler,
 * which barfs on our actual code that we're trying to import from statsComparison.
 * So instead, we have to do this work-around so we can pre-build dangerfile.ts using
 * our normal server build process.
 *
 * Also remember that the "danger" module exists only for types - at runtime, importing
 * it throws an error, because instead danger puts all the DSL bits into global scope
 * directly.
 */
function dangerImport<T extends keyof typeof import("danger")>(name: T) {
	const value: typeof import("danger")[T] = (global as any)[name]
	return value
}

const danger = dangerImport("danger")
const fail = dangerImport("fail")
const schedule = dangerImport("schedule")
const message = dangerImport("message")
const warn = dangerImport("warn")