Metaschema specifying required attribute for all properties - json

Question

I want to customize a metaschema such that all properties are required to have an additional attribute, for example, how could I require that all properties specify a "type"?
Then this schema should fail:
{
"$schema": "http://json-schema.org/schema#",
"title": "...",
"description": "...",
"type": "object",
"properties": {
"name": {
"description": "..."
}
}
}
But this one should succeed:
{
"$schema": "http://json-schema.org/schema#",
"title": "...",
"description": "...",
"type": "object",
"properties": {
"name": {
"description": "...",
"type": "string"
}
}
}

Answer 1

Unfortunately, writing meta-schemas is not easy. It's being worked on, but there's no good solution yet.
You would have to make a copy of the meta-schema you want to extend and then add "required": ["type"].
But, while we're here, maybe I can convince you not to do this. Making the type keyword required causes problems in some cases. Here are a few examples. https://github.com/json-schema/json-schema/issues/172#issuecomment-124214534
EDIT
After discussing this further, we found that this particular case doesn't have the problems we normally run into with extending meta-schemas because it doesn't need to be recursive. Here is an example of extending the draft-06 schema to include a new keyword called custom which is a boolean and is required only at the top level of a properties schema.
{
"allOf": [
{ "$ref": "http://json-schema.org/draft-06/schema#" },
{
"properties": {
"properties": {
"patternProperties": {
".*": {
"properties": {
"custom": { "type": "boolean" }
},
"required": ["custom"]
}
}
}
}
}
]
}
And here's an example schema that conforms to this meta-schema.
{
"properties": {
"foo": {
"custom": true,
"not": { "type": "string" }
}
}
}
The custom keyword is required for the "foo" schema, but not the not schema or the top level schema.