plainleaf/libraries/Library/Std/APIs/Schema.md

description, tags

description	tags
Helper functions for building JSON Schema objects in Lua	meta/api

Helper functions for succinctly defining JSON Schema types in Lua.

API

schema.string()

Returns {type = "string"}.

schema.number()

Returns {type = "number"}.

schema.boolean()

Returns {type = "boolean"}.

schema.null()

Returns {type = "null"}.

schema.array(typ)

Returns an array schema with items of the given type. typ can be a type string (e.g. "string") or a full schema table.

Example:

schema.array("string")    -- {type = "array", items = {type = "string"}}
schema.array {
    type = "object",
    properties = {
        name = {type = "string"}
    }
}

schema.nullable(typ)

Allows the given type or null. typ can be a type string or a schema table.

schema.nullableArray(typ)

An array of the given type, or null.

schema.func()

Marker for function-typed values.

schema.schema()

Marker for schema-typed values.

Implementation

-- priority: 101
schema = schema or {}

function schema.string()
  return { type = "string" }
end

function schema.number()
  return { type = "number" }
end

function schema.boolean()
  return { type = "boolean" }
end

function schema.array(typ)
  if type(typ) == "string" then
    return {
      type = "array",
      items = { type = typ }
    }
  else
    return {
      type = "array",
      items = typ,
    }
  end
end

function schema.nullable(typ)
  if type(typ) == "string" then
    return {
      anyOf = {
        { type = typ },
        { type = "null" },
      }
    }
  else
    return {
      anyOf = {
        typ,
        { type = "null" },
      }
    }
  end
end

function schema.nullableArray(typ)
  if type(typ) == "string" then
    return {
      anyOf = {
        { type = "array",
          items = { type = typ } },
        { type =  "null" },
      }
    }
  else
    return {
      anyOf = {
        { type = "array",
          items = typ, },
        { type = "null" },
      }
    }
  end
end

-- Used to specify we're expecting a function, but doesn't deeply validate
function schema.func()
  return {}
end

-- Used to specify we're expecting a schema, but doesn't deeply validate
function schema.schema()
  return { type = "object" }
end

function schema.null()
  return { type = "null" }
end