fix(client-sdks): handle 204 empty responses with runtime validation (#288)

Adds e2e tests for endpoints returning `204` / empty responses and
relaxes runtime schema validation for clients to use `any`, allowing for
`axios` returning an `""`

Keeps the type as `void` which is somewhat a lie, but I believe a
pragmatic decision - in practice you shouldn't be looking at the
response body for a `204` at all, so it shouldn't really matter. The
`fetch` client will continue to throw a JSON parse error if you attempt
to read the empty response, which I think is fine for the same reason.

An alternative might've been to use a `.transform(it => undefined)` to
coerce the runtime value to `undefined` but I don't think there is all
that much value in this.

closes #285

Author: mnahkies

e2e/openapi.yaml

@@ -74,7 +74,13 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/RandomNumber'
-
+  /responses/empty:
+    get:
+      tags:
+        - validation
+      responses:
+        204:
+          description: Ok
 components:
   responses:
     GetHeaders:

e2e/src/generated/client/axios/client.ts

@@ -198,4 +198,13 @@ describe("e2e - typescript-axios client", () => {
       })
     })
   })
+
+  describe("GET /responses/empty", () => {
+    it("returns undefined", async () => {
+      const {status, data} = await client.getResponsesEmpty()
+
+      expect(status).toBe(204)
+      expect(data).toEqual("")
+    })
+  })
 })

e2e/src/generated/client/fetch/client.ts

@@ -224,4 +224,13 @@ describe("e2e - typescript-fetch client", () => {
       })
     })
   })
+
+  describe("GET /responses/empty", () => {
+    it("returns undefined", async () => {
+      const res = await client.getResponsesEmpty()
+
+      expect(res.status).toBe(204)
+      await expect(res.json()).rejects.toThrow("Unexpected end of JSON input")
+    })
+  })
 })

e2e/src/generated/routes/validation.ts

@@ -1,4 +1,5 @@
 import {
+  type GetResponsesEmpty,
   type GetValidationNumbersRandomNumber,
   createRouter,
 } from "../generated/routes/validation"
@@ -28,8 +29,13 @@ const getValidationNumbersRandomNumber: GetValidationNumbersRandomNumber =
     return respond.withStatus(404)
   }
 
+const getResponsesEmpty: GetResponsesEmpty = async (_, respond) => {
+  return respond.with204()
+}
+
 export function createValidationRouter() {
   return createRouter({
     getValidationNumbersRandomNumber,
+    getResponsesEmpty,
   })
 }

e2e/src/index.axios.spec.ts

@@ -128,7 +128,7 @@ export class ClientOperationBuilder {
           acc.defaultResponse = {
             schema: content
               ? schemaBuilder.fromModel(content.schema, true, true)
-              : schemaBuilder.void(),
+              : schemaBuilder.any(),
             type: content ? models.schemaObjectToType(content.schema) : "void",
           }
         } else {
@@ -138,7 +138,7 @@ export class ClientOperationBuilder {
             type: content ? models.schemaObjectToType(content.schema) : "void",
             schema: content
               ? schemaBuilder.fromModel(content.schema, true, true)
-              : schemaBuilder.void(),
+              : schemaBuilder.any(),
           })
         }
 

e2e/src/index.fetch.spec.ts

@@ -404,7 +404,7 @@ export abstract class AbstractSchemaBuilder<
 
   protected abstract boolean(): string
 
-  protected abstract any(): string
+  public abstract any(): string
 
   protected abstract unknown(): string
 

e2e/src/routes/validation.ts

@@ -259,7 +259,7 @@ export class JoiBuilder extends AbstractSchemaBuilder<
       .join(".")
   }
 
-  protected any(): string {
+  public any(): string {
     return [joi, "any()"].filter(isDefined).join(".")
   }