Fix Record<string, never> appearing in discriminator union

Author: drwpow

.changeset/old-owls-whisper.md

@@ -0,0 +1,5 @@
+---
+"openapi-typescript": patch
+---
+
+Fix Record<string, never> appearing in union

.eslintrc.cjs

@@ -4,8 +4,8 @@ module.exports = {
   parserOptions: {
     project: ["./tsconfig.json"],
   },
-  extends: ["eslint:recommended", "plugin:@typescript-eslint/strict"],
-  plugins: ["@typescript-eslint", "prettier"],
+  extends: ["eslint:recommended", "plugin:@typescript-eslint/strict", "plugin:vitest/recommended"],
+  plugins: ["@typescript-eslint", "no-only-tests", "prettier", "vitest"],
   rules: {
     "@typescript-eslint/consistent-indexed-object-style": "off", // sometimes naming keys is more user-friendly
     "@typescript-eslint/no-dynamic-delete": "off", // delete is OK
@@ -19,6 +19,8 @@ module.exports = {
       rules: {
         "@typescript-eslint/ban-ts-comment": "off", // allow @ts-ignore only in tests
         "@typescript-eslint/no-empty-function": "off", // don’t enforce this in tests
+        "no-only-tests/no-only-tests": "error",
+        "vitest/valid-title": "off", // doesn’t work?
       },
     },
   ],

package.json

@@ -27,7 +27,9 @@
     "del-cli": "^5.0.0",
     "eslint": "^8.44.0",
     "eslint-config-prettier": "^8.8.0",
+    "eslint-plugin-no-only-tests": "^3.1.0",
     "eslint-plugin-prettier": "^4.2.1",
+    "eslint-plugin-vitest": "^0.2.6",
     "npm-run-all": "^4.1.5",
     "prettier": "^2.8.8",
     "typescript": "^5.1.6"

packages/openapi-fetch/package.json

@@ -48,7 +48,8 @@
     "build:ts-min": "esbuild --bundle src/index.ts --format=esm --minify --outfile=dist/index.min.js && cp dist/index.d.ts dist/index.min.d.ts",
     "build:cjs": "esbuild --bundle src/index.ts --format=cjs --outfile=dist/index.cjs",
     "lint": "pnpm run lint:js",
-    "lint:js": "prettier --check \"{src,test}/**/*\"",
+    "lint:js": "eslint \"{src,test}/**/*.{js,ts}\"",
+    "lint:prettier": "prettier --check \"{src,test}/**/*\"",
     "test": "pnpm run test:ts && npm run test:js",
     "test:js": "vitest run",
     "test:ts": "tsc --noEmit",

packages/openapi-fetch/src/index.test.ts

@@ -227,6 +227,8 @@ describe("client", () => {
     });
 
     describe("body", () => {
+      // these are pure type tests; no runtime assertions needed
+      /* eslint-disable vitest/expect-expect */
       it("requires necessary requestBodies", async () => {
         const client = createClient<paths>({ baseUrl: "https://myapi.com/v1" });
         mockFetch({ status: 200, body: JSON.stringify({ message: "OK" }) });
@@ -285,6 +287,7 @@ describe("client", () => {
         });
       });
     });
+    /* eslint-enable vitest/expect-expect */
   });
 
   describe("options", () => {
@@ -408,7 +411,7 @@ describe("client", () => {
       expect(response.status).toBe(204);
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
 
     it("treats `default` as an error", async () => {
@@ -478,7 +481,7 @@ describe("client", () => {
       expect(response.status).toBe(200);
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
 
     it("sends correct options, returns error", async () => {
@@ -500,7 +503,7 @@ describe("client", () => {
       expect(response.status).toBe(404);
 
       // assert data is empty
-      expect(data).toBe(undefined);
+      expect(data).toBeUndefined();
     });
 
     // note: this was a previous bug in the type inference
@@ -543,7 +546,7 @@ describe("client", () => {
       expect(response.status).toBe(201);
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
 
     it("supports sepecifying utf-8 encoding", async () => {
@@ -563,7 +566,7 @@ describe("client", () => {
       expect(response.status).toBe(201);
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
   });
 
@@ -588,7 +591,7 @@ describe("client", () => {
       expect(data).toEqual({});
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
 
     it("returns empty object on Content-Length: 0", async () => {
@@ -604,7 +607,7 @@ describe("client", () => {
       expect(data).toEqual({});
 
       // assert error is empty
-      expect(error).toBe(undefined);
+      expect(error).toBeUndefined();
     });
   });
 

packages/openapi-typescript/examples/digital-ocean-api.ts

@@ -7,11 +7,6 @@
 /** WithRequired type helpers */
 type WithRequired<T, K extends keyof T> = T & { [P in K]-?: T[P] };
 
-/** OneOf type helpers */
-type Without<T, U> = { [P in Exclude<keyof T, keyof U>]?: never };
-type XOR<T, U> = (T | U) extends object ? (Without<T, U> & U) | (Without<U, T> & T) : T | U;
-type OneOf<T extends any[]> = T extends [infer Only] ? Only : T extends [infer A, infer B, ...infer Rest] ? OneOf<[XOR<A, B>, ...Rest]> : never;
-
 export interface paths {
   "/v2/1-clicks": {
     get: external["resources/1-clicks/oneClicks_list.yml"]
@@ -8231,17 +8226,17 @@ export interface external {
       "ratelimit-reset": external["shared/headers.yml"]["ratelimit-reset"];
     };
     content: {
-      "application/json": OneOf<[{
+      "application/json": {
         droplet: external["resources/droplets/models/droplet.yml"];
         links: {
           actions?: external["shared/models/action_link.yml"][];
         };
-      }, {
+      } | {
         droplets: external["resources/droplets/models/droplet.yml"][];
         links: {
           actions?: external["shared/models/action_link.yml"][];
         };
-      }]>;
+      };
     };
   }
   "resources/droplets/responses/droplet_neighbors_ids.yml": {
@@ -9048,13 +9043,13 @@ export interface external {
       droplet_id: number;
     };
   };
-  "resources/floating_ips/models/floating_ip_create.yml": OneOf<[{
+  "resources/floating_ips/models/floating_ip_create.yml": {
     /**
      * @description The ID of the Droplet that the floating IP will be assigned to.
      * @example 2457247
      */
     droplet_id: number;
-  }, {
+  } | {
     /**
      * @description The slug identifier for the region the floating IP will be reserved to.
      * @example nyc3
@@ -9066,7 +9061,7 @@ export interface external {
      * @example 746c6152-2fa2-11ed-92d3-27aaa54e4988
      */
     project_id?: string;
-  }]>
+  }
   "resources/floating_ips/models/floating_ip.yml": {
     /**
      * Format: ipv4
@@ -11760,15 +11755,15 @@ export interface external {
     disable_lets_encrypt_dns_records?: boolean;
     firewall?: external["resources/load_balancers/models/lb_firewall.yml"];
   }
-  "resources/load_balancers/models/load_balancer_create.yml": OneOf<[WithRequired<{
+  "resources/load_balancers/models/load_balancer_create.yml": (WithRequired<{
     $ref?: external["resources/load_balancers/models/attributes.yml"]["load_balancer_droplet_ids"];
   } & {
     region?: external["shared/attributes/region_slug.yml"];
-  } & external["resources/load_balancers/models/load_balancer_base.yml"], "droplet_ids" | "region">, WithRequired<{
+  } & external["resources/load_balancers/models/load_balancer_base.yml"], "droplet_ids" | "region">) | (WithRequired<{
     $ref?: external["resources/load_balancers/models/attributes.yml"]["load_balancer_droplet_tag"];
   } & {
     region?: external["shared/attributes/region_slug.yml"];
-  } & external["resources/load_balancers/models/load_balancer_base.yml"], "tag" | "region">]>
+  } & external["resources/load_balancers/models/load_balancer_base.yml"], "tag" | "region">)
   "resources/load_balancers/models/load_balancer.yml": external["resources/load_balancers/models/load_balancer_base.yml"] & {
     region?: external["resources/regions/models/region.yml"];
   } & {
@@ -13782,13 +13777,13 @@ export interface external {
       droplet_id: number;
     };
   };
-  "resources/reserved_ips/models/reserved_ip_create.yml": OneOf<[{
+  "resources/reserved_ips/models/reserved_ip_create.yml": {
     /**
      * @description The ID of the Droplet that the reserved IP will be assigned to.
      * @example 2457247
      */
     droplet_id: number;
-  }, {
+  } | {
     /**
      * @description The slug identifier for the region the reserved IP will be reserved to.
      * @example nyc3
@@ -13800,7 +13795,7 @@ export interface external {
      * @example 746c6152-2fa2-11ed-92d3-27aaa54e4988
      */
     project_id?: string;
-  }]>
+  }
   "resources/reserved_ips/models/reserved_ip.yml": {
     /**
      * Format: ipv4