fix: openapi issues (#500)

* fix: arbitrary status for empty response

* feat: allow a union schema for response headers

Author: sukovanej

.changeset/fair-socks-jog.md

@@ -0,0 +1,5 @@
+---
+"effect-http": patch
+---
+
+Fix OpenApi with no body nor headers.

.changeset/large-pumas-jam.md

@@ -0,0 +1,5 @@
+---
+"effect-http": patch
+---
+
+Allow a union schema for response headers.

packages/effect-http/package.json

@@ -30,7 +30,7 @@
     "coverage": "vitest --coverage"
   },
   "dependencies": {
-    "schema-openapi": "^0.33.7"
+    "schema-openapi": "^0.34.0"
   },
   "peerDependencies": {
     "@effect/platform": "^0.48.15",

packages/effect-http/src/internal/open-api.ts

@@ -31,23 +31,19 @@ export const make = (
           const status = ApiResponse.getStatus(response)
 
           if (ApiSchema.isIgnored(body) && ApiSchema.isIgnored(headers)) {
-            operationSpec.push(OpenApi.noContentResponse("No response"))
+            operationSpec.push(OpenApi.noContentResponse("No response", status))
             continue
           }
 
-          const schema = ApiSchema.isIgnored(body) ? undefined : body
-          const setHeaders = ApiSchema.isIgnored(headers)
-            ? identity
-            : OpenApi.responseHeaders(
-              createResponseHeadersSchemaMap(headers)
-            )
+          const bodySchema = ApiSchema.isIgnored(body) ? undefined : body
+          const setHeaders = ApiSchema.isIgnored(headers) ? identity : createResponseHeaderSetter(headers)
 
           operationSpec.push(
             OpenApi.jsonResponse(
               status as OpenApiTypes.OpenAPISpecStatusCode,
-              schema,
+              bodySchema,
               `Response ${status}`,
-              schema ? descriptionSetter(schema) : identity,
+              bodySchema ? descriptionSetter(bodySchema) : identity,
               setHeaders
             )
           )
@@ -245,21 +241,10 @@ const createParameterSetters = (
   })
 }
 
-const createResponseHeadersSchemaMap = (schema: Schema.Schema<any, any, unknown>) => {
-  let ast = schema.ast
-
-  if (ast._tag === "Transformation") {
-    ast = ast.from
-  }
+const createResponseHeaderSetter = (schema: Schema.Schema<any, any, unknown>) => {
+  const ps = getPropertySignatures("header", schema.ast)
 
-  if (ast._tag !== "TypeLiteral") {
-    throw new Error(`Response headers must be a type literal schema`)
-  }
-
-  return Object.fromEntries(
-    ast.propertySignatures.map((ps) => [
-      ps.name,
-      Schema.make<unknown, string, never>(ps.type)
-    ])
+  return OpenApi.responseHeaders(
+    Object.fromEntries(ps.map((ps) => [ps.name, Schema.make(ps.type)]))
   )
 }

packages/effect-http/test/openapi.test.ts

@@ -1,6 +1,7 @@
 import { Schema } from "@effect/schema"
 import { pipe } from "effect"
 import { Api, ApiGroup, OpenApi, Security } from "effect-http"
+import type { OpenAPISpecStatusCode } from "schema-openapi/OpenApiTypes"
 import { expect, test } from "vitest"
 
 test("description", () => {
@@ -208,7 +209,6 @@ test("union in query params", () => {
     Api.make(),
     Api.addEndpoint(
       Api.post("myOperation", "/my-operation").pipe(
-        Api.setResponseBody(Schema.string),
         Api.setRequestQuery(Schema.union(
           Schema.struct({ a: Schema.string }),
           Schema.struct({ a: Schema.number, b: Schema.string }),
@@ -293,3 +293,37 @@ test("http security scheme", () => {
     }
   })
 })
+
+test("arbitrary status with empty response is allowed", () => {
+  const api = pipe(
+    Api.make(),
+    Api.addEndpoint(
+      Api.post("myOperation", "/my-operation", { description: "options" }).pipe(
+        Api.addResponse({ status: 401 })
+      )
+    )
+  )
+
+  const openApi = OpenApi.make(api)
+
+  // eslint-disable-next-line @typescript-eslint/no-non-null-asserted-optional-chain
+  expect(((openApi.paths["/my-operation"].post?.responses![401 as OpenAPISpecStatusCode])!).content).toBe(undefined)
+})
+
+test("response header as union", () => {
+  const api = pipe(
+    Api.make(),
+    Api.addEndpoint(
+      Api.post("myOperation", "/my-operation", { description: "options" }).pipe(
+        Api.setResponseHeaders(Schema.union(Schema.struct({}), Schema.struct({ a: Schema.string })))
+      )
+    )
+  )
+
+  const openApi = OpenApi.make(api)
+
+  // eslint-disable-next-line @typescript-eslint/no-non-null-asserted-optional-chain
+  const headerSpec = ((openApi.paths["/my-operation"].post?.responses![200 as OpenAPISpecStatusCode])!).headers!["a"]
+
+  expect(headerSpec).toEqual({ description: "a string", schema: { description: "a string", type: "string" } })
+})