GET [...]/rest.php/wikibase/v0/suggest/items?language=en&q=...
Request parameters (query parameters)

• q - search term
• language - language code

Response structure in pseudo-JSON

{
  "results": [
    {
      "id": "Q123",
      "display-label": {
        "language": "<language code of LABEL or ALIAS>",
        "value": "<LABEL or ALIAS of the matched Item/Property>"
      },
      "description": {
        "language": "<language code of DESCRIPTION>",
        "value": "<DESCRIPTION>"
      },
      "match": {
        "type": <"label" OR "alias">,
        "language": "<language code of LABEL or ALIAS>",
        "text": "<LABEL or ALIAS that matched the search query>"
      }
    },
    ...
  ]
}

Acceptance criteria:

• consider labels and aliases in the search, same as in the other existing RESTful search
• matching item/property when its ID is provided as the query works, same as in the other existing RESTful search
• Basic functionality of language fallback and matched data are implemented
• The only sophisticated functionality to be implemented will be pagination
• Errors to be the same as in simple item search
• URL matching i.e. matching item/property when its URL is provided as the query, same as in SimpleItemSearch

Task breakdown notes:

• OpenAPI schema
• create use case happy path with request and response objects
  • use the existing EntitySearchHelper prefix search implementation (works for both Cirrus- and sql-based search)
  • including unit tests
• request validation
• create RouteHandler that makes use of the use case + middlewares
  • including end-to-end test
• handle ID/URL matches
  • do what we did for T391663
• openapi validation test
• mark production ready