Generate pretty errors for validation errors

[dgmora]

Instead of

     Blumquist::Errors::ValidationError:
       [["The property '#/name' of type integer did not match the following type: string in schema 658659b8-41dc-5211-
9cb4-0912a8ab1cc4"],{"$schema":"http://json-schema.org/draft-04/schema#","definitions":{"address":{"type":"object","pr
operties":{"street_address":{"type":"string"},"city":{"type":"string"},"state":{"type":["string","null"]}},"required":
["street_address","city","state"]},"sibling":{"type":"object","properties":{"age_difference":{"type":"number"},"name":
{"type":"string"}},"required":["age_difference"]},"ancestor":{"type":"object","properties":{"family_name":{"type":"str
ing"}},"required":["family_name"]}},"type":"object","properties":{"name":{"type":"string","maxLength":16},"phone_numbe
rs":{"type":"array","items":[{"type":"object","properties":{"prefix":{"type":"number"},"extension":{"type":"number"}}}
]},"parents_address":{"$ref":"#/definitions/address"},"current_address":{"oneOf":[{"type":"null"},{"$ref":"#/definitio
ns/address"},{"type":"object","properties":{"planet":{"type":"string"}},"required":["planet"]}]},"relatives":{"type":"
array","items":{"oneOf":[{"$ref":"#/definitions/sibling"},{"$ref":"#/definitions/ancestor"}]}},"old_addresses":{"type"
:"array","items":[{"$ref":"#/definitions/address"}]}}},{"name":1,"phone_numbers":[{"prefix":555,"extension":1234}],"cu
rrent_address":{"street_address":"Chausseestr. 111","city":"Berlin","state":"Berlin"},"old_addresses":[{"street_addres
s":"Friedrichstr. 58","city":"Berlin","state":"Berlin"},{"street_address":"Mehringdamm 33","city":"Berlin","state":"Be
rlin"},{"street_address":"Bluecherstr. 22","city":"Berlin","state":"Berlin"}]}]

You see:

Blumquist::Errors::ValidationError:
  [
    [
      "The property '#/name' of type integer did not match the following type: string in schema 658659b8-41dc-5211-9cb4-0912a8ab1cc4"
    ],
    {
      "name": 1,
      "phone_numbers": [
        {
          "prefix": 555,
          "extension": 1234
        }
      ],
      "current_address": {
        "street_address": "Chausseestr. 111",
        "city": "Berlin",
        "state": "Berlin"
      },
      "old_addresses": [
        {
          "street_address": "Friedrichstr. 58",
          "city": "Berlin",
          "state": "Berlin"
        },
        {
          "street_address": "Mehringdamm 33",
          "city": "Berlin",
          "state": "Berlin"
        },
        {
          "street_address": "Bluecherstr. 22",
          "city": "Berlin",
          "state": "Berlin"
        }
      ]
    },
    {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "definitions": {
        "address": {
          "type": "object",
          "properties": {
            "street_address": {
              "type": "string"
            },
            "city": {
              "type": "string"
            },
            "state": {
              "type": [
                "string",
                "null"
              ]
            }
          },
          "required": [
            "street_address",
            "city",
            "state"
          ]
        },
        "sibling": {
          "type": "object",
          "properties": {
            "age_difference": {
              "type": "number"
            },
            "name": {
              "type": "string"
            }
          },
          "required": [
            "age_difference"
          ]
        },
        "ancestor": {
          "type": "object",
          "properties": {
            "family_name": {
              "type": "string"
            }
          },
          "required": [
            "family_name"
          ]
        }
      },
      "type": "object",
      "properties": {
        "name": {
          "type": "string",
          "maxLength": 16
        },
        "phone_numbers": {
          "type": "array",
          "items": [
            {
              "type": "object",
              "properties": {
                "prefix": {
                  "type": "number"
                },
                "extension": {
                  "type": "number"
                }
              }
            }
          ]
        },
        "parents_address": {
          "$ref": "#/definitions/address"
        },
        "current_address": {
          "oneOf": [
            {
              "type": "null"
            },
            {
              "$ref": "#/definitions/address"
            },
            {
              "type": "object",
              "properties": {
                "planet": {
                  "type": "string"
                }
              },
              "required": [
                "planet"
              ]
            }
          ]
        },
        "relatives": {
          "type": "array",
          "items": {
            "oneOf": [
              {
                "$ref": "#/definitions/sibling"
              },
              {
                "$ref": "#/definitions/ancestor"
              }
            ]
          }
        },
        "old_addresses": {
          "type": "array",
          "items": [
            {
              "$ref": "#/definitions/address"
            }
          ]
        }
      }
    }
  ]

It is quite long but it's at least readable. Do you think we could remove the schema from the exception? The schema should be available for the user somewhere, but then you can't find the error by just looking at the exception.

[jayniz]

Yeah, out with the schema!

[coveralls]

Coverage remained the same at 88.108% when pulling 89a9571 on prettier-errors into fb3d650 on master.

[dgmora]

@jayniz I had to add this because when there were errors in arrays you'd get:

         "The property '#/foo/0' of type object matched more than one of the required schemas. The schema
 specific errors were:\n\n- oneOf #0:\n    - The property '#/foo/0' did not contain a required property o
f 'title'\n- oneOf #3:\n    - The property '#/foo/0' did not contain a required property of 'other prop'\n- The property
 '#/foo/1' did not contain a required property of 'title'\n- oneOf #3:\n    - The property '#/foo/1'
did not contain a required property of 'other prop'\n
...

As the \n are inside a string, those get unscaped when transformed to json.
To avoid that, I transformed the errors from strings to arrays. It looks a bit better:

           [
             "The property '#/foo/0' of type object matched more than one of the required schemas. The sc
hema specific errors were:",
             "",
             "- oneOf #0:",
             "    - The property '#/foo/0' did not contain a required property of 'title'",
             "- oneOf #3:",
             "    - The property '#/foo/0' did not contain a required property of 'other prop'",

At some point I think we could dump all the json errors part.