ajv: Limitation: JSONSchemaType does not support unions

What version of Ajv are you using? Does the issue happen if you use the latest version?

ajv@7.0.0-beta.1

Ajv options object

N/A (type error)

JSON Schema

See code below

Sample data

N/A (type error)

Your code

type VariableGroupValue = string | number | { query: string };

const variableGroupValueSchema: JSONSchemaType<VariableGroupValue> = {
  anyOf: [
    {
      type: 'string',
    },
    {
      type: 'number',
    },
    {
      type: 'object',
      properties: {
        query: {
          type: 'string',
        },
      },
      required: ['query'],
      additionalProperties: false,
    },
  ],
};

Validation result, data AFTER validation, error messages

const variableGroupValueSchema: JSONSchemaType<VariableGroupValue, false>
Type '{ anyOf: ({ type: "string"; } | { type: "number"; } | { type: "object"; properties: { query: { type: "string"; }; }; required: "query"[]; additionalProperties: false; })[]; }' is not assignable to type 'JSONSchemaType<VariableGroupValue, false>'.
  Type '{ anyOf: ({ type: "string"; } | { type: "number"; } | { type: "object"; properties: { query: { type: "string"; }; }; required: "query"[]; additionalProperties: false; })[]; }' is not assignable to type '{ type: "object"; required: "query"[]; additionalProperties: boolean; properties?: PropertiesSchema<{ query: string; }> | undefined; patternProperties?: { [pattern: string]: never; } | undefined; propertyNames?: JSONSchemaType<...> | undefined; dependencies?: { ...; } | undefined; minProperties?: number | undefined;...'.
    Type '{ anyOf: ({ type: "string"; } | { type: "number"; } | { type: "object"; properties: { query: { type: "string"; }; }; required: "query"[]; additionalProperties: false; })[]; }' is missing the following properties from type '{ type: "object"; required: "query"[]; additionalProperties: boolean; properties?: PropertiesSchema<{ query: string; }> | undefined; patternProperties?: { [pattern: string]: never; } | undefined; propertyNames?: JSONSchemaType<...> | undefined; dependencies?: { ...; } | undefined; minProperties?: number | undefined;...': type, required, additionalPropertiests(2322)
Peek Problem (Alt+F8)
No quick fixes available

It complains that the top level schema object doesn’t have the keys: type, required, additionalPropertiests. I thought I could use anyOf on it’s own. It doesn’t really make sense to use type at the top level because it could be one of three different types but it looks like it expects it to be an object. I also tried oneOf with the same result.

Any suggestions or workarounds welcome, especially if my schema is wrong. Thanks

What results did you expect?

Expected no type error

Are you going to resolve the issue?

No.