Improve types and validation

Author: ehmicky

src/main.test-d.ts

@@ -25,6 +25,7 @@ ModernError.subclass('TestError', {
 // @ts-expect-error
 BaseError.beautiful(error, true)
 expectNotAssignable<Options>(true)
+
 ModernError.subclass('TestError', {
   plugins: [modernErrorsBeautiful],
   // @ts-expect-error
@@ -34,6 +35,24 @@ ModernError.subclass('TestError', {
 BaseError.beautiful(error, { unknown: true })
 expectNotAssignable<Options>({ unknown: true })
 
+ModernError.subclass('TestError', {
+  plugins: [modernErrorsBeautiful],
+  // @ts-expect-error
+  beautiful: { classes: {} },
+})
+// @ts-expect-error
+BaseError.beautiful(error, { classes: {} })
+expectNotAssignable<Options>({ classes: {} })
+
+ModernError.subclass('TestError', {
+  plugins: [modernErrorsBeautiful],
+  // @ts-expect-error
+  beautiful: { custom: 'pretty' },
+})
+// @ts-expect-error
+BaseError.beautiful(error, { custom: 'pretty' })
+expectNotAssignable<Options>({ custom: 'pretty' })
+
 ModernError.subclass('TestError', {
   plugins: [modernErrorsBeautiful],
   beautiful: { stack: true },

src/main.test.ts

@@ -20,7 +20,13 @@ const innerError = new DatabaseError('inner')
 const outerError = new ExitCodeError('test', { errors: [innerError] })
 
 each(
-  [true, { stack: 'true' }, { unknown: true }, { classes: {} }],
+  [
+    true,
+    { stack: 'true' },
+    { unknown: true },
+    { classes: {} },
+    { custom: 'pretty' },
+  ],
   ({ title }, options) => {
     test(`Options are validated | ${title}`, (t) => {
       // @ts-expect-error Type checking should fail due to invalid options

src/main.ts

@@ -1,22 +1,28 @@
-import beautifulError, { validateOptions, type Options } from 'beautiful-error'
+import beautifulError, {
+  validateOptions,
+  type Options as BeautifulErrorOptions,
+} from 'beautiful-error'
 import type { Info, Plugin } from 'modern-errors'
 
 /**
  * Options of `modern-errors-beautiful`
  */
-export type { Options }
+export type Options = Omit<BeautifulErrorOptions, 'classes' | 'custom'>
 
 // `error.beautiful()` is called with `errorString` as argument by
 // `beautiful-error`. We ignore that argument and prevent it from being
 // considered an invalid options object.
 const isOptions = (options: unknown) => typeof options !== 'string'
 
 const getOptions = (options: Options = {}) => {
-  // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
   validateOptions(options)
 
   if (options.classes !== undefined) {
-    throw new TypeError('"classes" must not be defined.')
+    throw new TypeError('The "classes" option must not be defined.')
+  }
+
+  if (options.custom !== undefined) {
+    throw new TypeError('The "custom" option must not be defined.')
   }
 
   return options