feat(ajv): Keep original validation type while using errorMessage

[ktunador]

When errorMessage is used, ajv returns a special error object, error.keyword='errorMessage', and keeps original validation errors in the error.errors field.

The proposed changes normalize the ajv validation errors by unwrapping the errorMessage error object, so the resolver returns original error types, such as required and pattern, while using custom error messages. The normalization also allows us to use errorMessage at the root level (fixes #615).

As you can see in the before and after outputs, the value of the type field and the keys of the types field use the original validation type instead of errorMessage.

Before

  "password": {
    "message": "One uppercase character",
    "ref": {
      "name": "password",
    },
    "type": "errorMessage",
    "types": {
      "errorMessage": "One uppercase character",
    },
  },

After

  "password": {
    "message": "One uppercase character",
    "ref": {
      "name": "password",
    },
    "type": "pattern",
    "types": {
      "pattern": "One uppercase character",
    },
  },

Example schema

const schema = {
  type: "object",
  properties: {
    username: {
      type: "string",
      minLength: 3,
      errorMessage: {
        minLength: "username should be at least three characters long",
      },
    },
    password: {
      type: "string",
      pattern: ".*[A-Z].*",
      minLength: 8,
      errorMessage: {
        pattern: "One uppercase character",
        minLength: "passwords should be at least eight characters long",
      },
    },
  },
  required: ["username", "password"],
  additionalProperties: false,
  errorMessage: {
    required: {
      username: "username field is required",
      password: "password field is required",
    },
  },
};

Input Value

const value = {
  username: "kt",
  password: "invalid",
};

Resolver Output

{
  "errors": {
    "password": {
      "message": "One uppercase character",
      "ref": {
        "name": "password"
      },
      "type": "pattern",
      "types": {
        "minLength": "passwords should be at least eight characters long",
        "pattern": "One uppercase character"
      }
    },
    "username": {
      "message": "username should be at least three characters long",
      "ref": {
        "name": "username"
      },
      "type": "minLength",
      "types": {
        "minLength": "username should be at least three characters long"
      }
    }
  },
  "values": {}
}

Input Value

const value = {};

Resolver Output

{
  "errors": {
    "password": {
      "message": "password field is required",
      "ref": {
        "name": "password"
      },
      "type": "required",
      "types": {
        "required": "password field is required"
      }
    },
    "username": {
      "message": "username field is required",
      "ref": {
        "name": "username"
      },
      "type": "required",
      "types": {
        "required": "username field is required"
      }
    }
  },
  "values": {}
}