fix(validator): ignore content-type mismatches

[yusukebe]

With this PR, the validator will ignore the mismatch between the validate type like json and form and the content type of the incoming request.

Before this PR, it will throw the error if the validator validates a request that does not have a valid content type for validate type, including json and form:

const app = new Hono()
app.post(
  '/post',
  validator('json', (value) => value),
  (c) => {
    return c.json(c.req.valid('json'))
  }
)

const res = await app.request('http://localhost/post', {
  method: 'POST',
  body: JSON.stringify({ foo: 'bar' }),
  headers: {
    // Does not set a content-type
  },
})

// res.status will be 400!

This is inconvenient since it can't allow requests with no content type.

And with this spec, it does not support multiple validators for the body:

app.post(
  '/',
  validator('json', (value) => value),
  validator('form', (value) => value),
  async (c) => {
    const jsonData = c.req.valid('json')
    const formData = c.req.valid('form')
    return c.json({
      json: jsonData,
      form: formData,
    })
  }
)

With this PR, it does not throw errors.

Is this a breaking change?

I've changed the test behavior. However, the current implementation causes unintended results like honojs/middleware#638. So, I think we can include this in a patch or minor release, not a major release.

Fixes honojs/middleware#638

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.20%. Comparing base (f23a416) to head (d6111b3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3165      +/-   ##
==========================================
+ Coverage   96.18%   96.20%   +0.01%     
==========================================
  Files         151      151              
  Lines       15056    15062       +6     
  Branches     2623     2597      -26     
==========================================
+ Hits        14482    14490       +8     
+ Misses        574      572       -2     

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