Data Sources

A data source provides definitions to the resolver. Every call to showwhat() or resolve() needs one, passed via options.data.

Interface	Purpose
DefinitionReader	Read definitions: get, getAll, listKeys, plus lifecycle
DefinitionWriter	Write definitions: put, delete, putMany, plus lifecycle
DefinitionData	Combined read + write (DefinitionReader & DefinitionWriter)

Built-in

Source	Description
MemoryData	In-memory. Parse YAML or JSON, no I/O after setup.

Custom

Need to load definitions from a database, API, or filesystem? Implement DefinitionReader. For read-write sources, add DefinitionWriter too. Use isWritable() to check at runtime:

import { isWritable } from "showwhat";

if (isWritable(data)) {
  await data.put("my_flag", definition);
}

See the Custom Data Sources guide for full interface details and example implementations.