Lacinia and re-graph incompatible headers - clojure

Question

I'm using the last available lacinia version: "0.36.0-alpha-3" with Luminus (Ring+reitit), but this version asks for a specific header:
$ curl 'http://localhost:3000/api/graphql' -X POST --data "{test_by_id(id: 5) { title } }" -H 'Content-Type: application/graphql'
that request works fine, but without "'Content-Type: application/graphql'" the request wouldn't work. So I need to define my re-graph init vector like:
[::re-graph/init
{:ws-url nil
:http-url "http://localhost:3000/api/graphql"
:http-parameters {:with-credentials? false
:headers {"Content-Type" "application/graphql"}
}
:ws-reconnect-timeout nil
:resume-subscriptions? false
:connection-init-payload {}}]
but putting that header makes re-graph unable to work properly:
{"errors":[{"message":"Failed to parse GraphQL query.","extensions":{"errors":[{"locations":[{"line":1,"column":null}],"message":"mismatched input '\"query\"' expecting {'query', 'mutation', 'subscription',
it looks like re-graph sends and receives data using "application/json" header, so lacinia asks for some type of header but re-graph can't work with that option.

Answer 1

I had the same problem, and I think I got a solution for it. re-frame requests follows the Apollo Specification, as stated by #aarkerio. Here is the code to keep the original endpoint working with the origina specification, and allow it to respond to re-frame requests. This will make the endpoint respond to Graphiql request (from your http://localhost:3000/graphiql route), and re-graph ones. Any comments or corrections are welcomed.
Replace the original function set on the /graphql route on src/clj/mem_learning/routes/services.clj:
["/graphql" {:post graphql-call}
Add the graphql-call function on that same file:
(defn graphql-call [req]
(let [body (:body-params req)
content-type (keyword (get-in req [:headers "content-type"]))]
(case content-type
:application/json (ok (graphql/execute-request-re-graph body))
:application/graphql (ok (graphql/execute-request (-> req :body slurp))))))
add the execute-request-re-graph to the src/clj/mem_learning/routes/services/graphql.clj file:
(defn execute-request-re-graph
"execute request with re-graph/apollo format"
[{:keys [variables query context]}]
(lacinia/execute compiled-schema query variables context)))

Answer 2

ANSWER:
It looks that Luminus creates a middleware configuration:
(defn service-routes []
["/api"
{:coercion spec-coercion/coercion
:muuntaja formats/instance
:swagger {:id ::api}
:middleware [;; query-params & form-params
parameters/parameters-middleware
;; content-negotiation
muuntaja/format-negotiate-middleware
;; encoding response body
muuntaja/format-response-middleware
;; exception handling
exception/exception-middleware
;; decoding request body
muuntaja/format-request-middleware
;; coercing response bodys
coercion/coerce-response-middleware
;; coercing request parameters
coercion/coerce-request-middleware
;; multipart
multipart/multipart-middleware
]}
commenting the line "muuntaja/format-negotiate-middleware" makes the "application/json" call possible.
SECOND UPDATE (four hours later)
Ok, that muuntaja middleware thing was not the problem at all, the real problem is that curl send the data with the format:
{ test_by_id(id: 7, archived: false) { title } }
meanwhile re-graph uses:
{"query":"query { test_by_id(id: 7, archived: false) { title } }","variables":null}
this is a normal java string btw not a data structure, so we need to do some changes, first a new function:
(defn graphql-call [req]
(let [body (-> req :body slurp)
full-query (json/read-str body :key-fn keyword)
_ (log/info (str ">>> **** full-query >>>>> " full-query))]
(ok (graphql/execute-request full-query))))
we set the function:
["/graphql" {:post graphql-call}]
and in my_app.routes.services.graphql file:
(defn execute-request [{:keys [variables query context]}]
(json/write-str (lacinia/execute compiled-schema query variables context)))
and now re-graph works!
(also now I can send and use variables in GraphQL)
It's necessary to set:
:http-parameters {:with-credentials? false
:oauth-token "ah4rdSecr3t"
:headers {"Content-Type" "application/graphql"}
btw. Also, maybe it's better:
(lacinia/execute compiled-schema query variables context)
than:
(json/write-str (lacinia/execute compiled-schema query variables context))
because it interferes with re-graph importing the data already as a native ClojureScript map.