More informative errors

[rahulmutt]

I'm currently getting an error when I access the root path of my compojure-api app:

500 : {"type":"unknown-exception","class":"java.lang.RuntimeException"} http://localhost:8080/swagger.json

Then when I visit http://localhost:8080/swagger.json, I get a more informative error message, but it's still pretty obscure.

2015-12-29 23:05:48,250[qtp974317728-29 �[0m�[32m�[43m849b�[0m] ERROR compojure.api.exception - Bad explicit key: class java.lang.String
java.lang.RuntimeException: Bad explicit key: class java.lang.String
    at schema.core$explicit_schema_key.invoke(core.clj:725)
    at ring.swagger.json_schema$properties$iter__14975__14979$fn__14980.invoke(json_schema.clj:240)
       ...

So I understand the problem is with one of my schema specified in :return. I can debug this with trial-and-error going by adding/removing one schema at at time. But I was wondering if there was a way to get much more precise error messages like which route caused the failure, etc.

[Deraen]

metosin/ring-swagger#77

[rahulmutt]

Ok so I just used lein-git-deps to use the updated ring-swagger from github (specifically, commit 0b854b6). Now when I run the app, there are no more exceptions.

This was the schema that was causing problems:

      :return {:a s/Str
               :b {s/Str {:c s/Str
                          :d s/Int}}}

The /swagger.json endpoint is returning a JSON file, but now there's a new problem: From the main /index.html endpoint (swagger-ui), the following message is shown:

fetching resource list: http://localhost:8080/swagger.json; Please wait.

and it gets stuck there. This problem happened when I tried to remove the problematic schema (omitting the :return keyword) before adding the updated ring-swagger. After adding the new dependency, I added back the :return keyword for the problematic schema and the same behavior shows up again. Any ideas what's causing it to get stuck? There are no exceptions in the logs.

[ikitommi]

Hi. Agree on better error messages. For this case: your schema has a s/Str as a key, which is not currently allowed. s/Keyword should work. Will fix that soon.

[ikitommi]

the root cause should be fixed in [metosin/ring-swagger "0.22.2-SNAPSHOT"].

[rahulmutt]

Cool. Yeah that fixes it. But I still have the "stuck" problem. The JavaScript console gave the following error:

Uncaught TypeError: Swagger 2.0 does not support null types ([object Object],).  See https://github.com/swagger-api/swagger-spec/issues/229.

I have checked all my schemas and I do not have any "null" types.

UPDATE: After looking through my schemas for anything that can be "nullable" I found

(s/conditional empty? s/Str :else sc/Email)

That's probably bad API design from my end, but I take it that (s/conditional) is not supported either? Removing that conditional allowed me to see the API listing again.

[ikitommi]

So, there is no swagger-bindings for sc/Email, causing nil, which was not stripped away from s/Conditional output, causing the problem. fixed in the latest [metosin/ring-swagger "0.22.2-SNAPSHOT"].

But, Swagger has dropped support of the anyOf, so the generated spec of s/conditional is no more valid swagger spec. Might be back in the next version of the spec. There are some published workarounds, will apply the at some point.

[ikitommi]

metosin/ring-swagger@7a94465

[rahulmutt]

Currently, I use [kixi/schema-contrib "0.2.0"] for the sc/Email schema and the sc/URI which are sprinkled throughout the codebase inside of maps. What steps do I take to support these and add documentation for them so that they show up in the Swagger UI when I click on the endpoint?

[ikitommi]

See https://github.com/metosin/ring-swagger/blob/master/README.md#schema-to-swagger-json-schema-conversion.