Unified throws an error when a file "fails"; how to test this (or disable the behaviour during testing) ?

[matfire]

Hello,

I am writing a remark plugin and decided to write some tests. In the plugin, I have some validation logic that, when failing, calls file.fail() with some context information. Problem is, it appears as if the process throws an error (at least vitest thinks it does).

Here's what Vitest says:

Vitest caught 1 unhandled error during the test run.
This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

Here's the serialized error:

{ ancestors: undefined, fatal: true, place: undefined, reason: 'validation failed for element test', ruleId: undefined, file: '' }

which matches what I pass into the fail function.

When I try to "catch" the thrown error, it doesn't get caught.

How is everyone handling these use cases ?

Edit:
the code I'm talking about lives here: https://github.com/matfire/remark-directive-to-custom-tag
specifically in this file and branch https://github.com/matfire/remark-directive-to-custom-tag/blob/feat/schema/tests/schemas.test.ts

The specific error I'm getting is this one:

AssertionError: promise resolved "VFile{ …(5) }" instead of rejecting

- Expected
+ Received

- Error {
-   "message": "rejected promise",
+ VFile {
+   "cwd": "remark-directive-to-custom-tag",
+   "data": {},
+   "history": [],
+   "messages": [
+     1:1 {
+       "message": "validation failed for element test",
+       "cause": Error {
+         "message": "surname must be a string (was missing)",
+       },
+       "ancestors": undefined,
+       "column": undefined,
+       "fatal": true,
+       "line": undefined,
+       "name": "1:1",
+       "place": undefined,
+       "reason": "validation failed for element test",
+       "ruleId": undefined,
+     },
+   ],
+   "value": "<div></div>",
  }

[wooorm]

Yes, fail throws an error. You can catch errors indeed. If your catch doesn’t catch, then you have a bug. And I cannot look at your code and solve it if you don’t provide code.

[matfire]

Hey, thanks for the reply. I edited the main post to give a bit more context

[wooorm]

Your question has to do with Vite and how it deals with errors and how to use this chaining API.

I really strongly dislike chaining APIs such as this, because it makes everything so darn hard; so I don’t use it; so I am not an expert.

I like straight asserts:

const file = await readFile('./tests/files/schemas.md', 'utf-8')
const processor = unified()
  .use(remarkParse)
  .use(remarkDirective)
  .use(remarkDirectiveToCustomTag, {
    associations: [
      {
        type: 'leafDirective',
        directiveName: 'test',
        tagName: 'test',
        validator: type({
          name: 'string',
          surname: 'string'
        })
      }
    ]
  })
  .use(remarkRehype)
  .use(rehypeStringify)

try {
  await processor.process(file)
} catch (error) {
  assert.equal(error.message, 'to do: the expected thing')
}

I can recommend you to split things up in variables, as I did above.
I assume that something goes wrong for you with rejects.toThrowError.
But again, I do not know Vite’s APIs.
The docs or their forums will help you.

[matfire]

Ok, thank you! I'll try lookin on the vitest side.