Unexpected error because Human-friendly type descriptions are not possible for circular types that are not objects or unions

[amagee]

Small example:

src/mytypes.ts:

import createValidator, { createDetailedValidator, registerType } from "typecheck.macro";

export type ProjectLayerConfig = {
  layers: Array<Group | Layer>;
};
registerType("ProjectLayerConfig");

type Item = {
  id: string;
  label: string;
  isVisible: boolean;
};
registerType("Item");

export type Group = Item & {
  type: "Group";
  children: Array<Group | Layer>;
};
registerType("Group");

export type Layer = Item & {
  type: "Layer";
  children: SubLayer[];
};
registerType("Layer");

export type SubLayer = Item & {
  type: "SubLayer"
};
registerType("SubLayer");

const validator = createDetailedValidator<ProjectLayerConfig>();

package.json:

{
  "name": "typescript-babel",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "compile": "babel src --out-dir dist --extensions \".ts\""
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@babel/cli": "^7.12.16",
    "@babel/core": "^7.12.16",
    "@babel/plugin-transform-modules-commonjs": "^7.12.13",
    "@babel/preset-typescript": "^7.12.16",
    "babel-plugin-macros": "^3.0.1",
    "typecheck.macro": "^0.7.1"
  }
}

Output:

> typescript-babel@1.0.0 compile /path/typescript-babel
> babel src --out-dir dist --extensions ".ts"

MacroError: /path/typescript-babel/src/mcve.ts: Unexpected error because Human-friendly type descriptions are not possible for circular types that are not objects or unions. Please contact me, I didn't know this was possible!. Please report this to the developer.
    at throwUnexpectedError (/path/typescript-babel/node_modules/typecheck.macro/dist/macro-assertions.js:91:9)
    at visitInstantiatedType (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:116:49)
    at visitIR (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:73:10)
    at /path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:185:21
    at Array.map (<anonymous>)
    at visitObjectPattern (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:183:22)
    at visitIR (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:73:10)
    at humanFriendlyDescription (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToHumanFriendlyDescription.js:24:10)
    at /path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToInline.js:868:177
    at wrapFalsyExprWithErrorReporter (/path/typescript-babel/node_modules/typecheck.macro/dist/code-gen/irToInline.js:869:5) {
  name: 'MacroError',
  code: 'BABEL_TRANSFORM_ERROR'
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! typescript-babel@1.0.0 compile: `babel src --out-dir dist --extensions ".ts"`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the typescript-babel@1.0.0 compile script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/amagee/.npm/_logs/2021-02-15T22_28_06_776Z-debug.log

Note: if I use createValidator instead of createDetailedValidator, it succeeds.

[vedantroy]

Hi! Thanks for the bug report. Will look into it.