trace-type.ts

const callStack: string[] = []
const MAX_DEPTH = 1500
const SNIPPET_LEN = 60

function snippet(text: string) {
  return text.replace(/\s+/g, ' ').slice(0, SNIPPET_LEN)
}

/** Traces the type and its enclosing node. */
function traceType(type: Type, node?: Node) {
  let nodeInfo = ''

  if (node) {
    const kindName = tsMorph.SyntaxKind[node.getKind()]
    const location = node.getSourceFile()
      ? node.getStartLineNumber() + ':' + node.getStartLinePos()
      : null
    nodeInfo = ` • ${kindName}${location ? `@${location}` : ''} ➜ ${snippet(node.getText())}`
  }

  callStack.push(
    `${snippet(type.getText(undefined, TYPE_FORMAT_FLAGS))}${nodeInfo}`
  )

  if (callStack.length > MAX_DEPTH) {
    throw new Error(
      'resolveType recursion depth exceeded > ' +
        MAX_DEPTH +
        '\n' +
        callStack.join('\n ↳ ')
    )
  }
}