fix(typescript): simplify types by using [Conditional Types](https://www.typescriptlang.org/docs/handbook/2/conditional-types.html) (#132)

Author: gr2m

README.md

@@ -267,13 +267,15 @@ Returns an array of strings. Returns <code>options.scopes</code> if it was set a
 ## Types
 
 ```ts
-import { ClientType, Options, Result } from "@octokit/oauth-authorization-url";
+import {
+  ClientType,
+  OAuthAppOptions,
+  OAuthAppResult,
+  GitHubAppOptions,
+  GitHubAppResult,
+} from "@octokit/oauth-authorization-url";
 ```
 
-- `ClientType` is a union of `"oauth-app"` and `"github-app"`
-- `Options<"oauth-app">` returns types for OAuth Apps Options. `Options<"github-app">` returns types for GitHub Apps Options.
-- `Result<"oauth-app">` returns types for OAuth Apps Result object. `Result<"github-app">` returns types for GitHub Apps Result object.
-
 ## License
 
 [MIT](LICENSE)

src/index.ts

@@ -1,19 +1,30 @@
-import { ClientType, Options, Result } from "./types";
-export { ClientType, Options, Result } from "./types";
+import {
+  ClientType,
+  OAuthAppOptions,
+  GitHubAppOptions,
+  OAuthAppResult,
+  GitHubAppResult,
+} from "./types";
+export {
+  ClientType,
+  OAuthAppOptions,
+  GitHubAppOptions,
+  OAuthAppResult,
+  GitHubAppResult,
+} from "./types";
 
-export function oauthAuthorizationUrl<
-  TClientType extends ClientType = "oauth-app"
->(options: Options<TClientType>): Result<TClientType> {
-  const scopesNormalized =
-    typeof options.scopes === "string"
-      ? options.scopes.split(/[,\s]+/).filter(Boolean)
-      : Array.isArray(options.scopes)
-      ? options.scopes
-      : [];
+export function oauthAuthorizationUrl(options: OAuthAppOptions): OAuthAppResult;
+export function oauthAuthorizationUrl(
+  options: GitHubAppOptions
+): GitHubAppResult;
 
+export function oauthAuthorizationUrl(
+  options: Record<string, unknown>
+): Record<string, unknown> {
   const clientType = options.clientType || "oauth-app";
   const baseUrl = options.baseUrl || "https://github.com";
-  const common = {
+  const result: Record<string, unknown> = {
+    clientType,
     allowSignup: options.allowSignup === false ? false : true,
     clientId: options.clientId,
     login: options.login || null,
@@ -22,21 +33,17 @@ export function oauthAuthorizationUrl<
     url: "",
   };
 
-  const result =
-    clientType === "oauth-app"
-      ? {
-          ...common,
-          clientType: "oauth-app",
-          scopes: scopesNormalized,
-        }
-      : {
-          ...common,
-          clientType: "github-app",
-        };
+  if (clientType === "oauth-app") {
+    const scopes = "scopes" in options ? options.scopes : [];
+    result.scopes =
+      typeof scopes === "string"
+        ? scopes.split(/[,\s]+/).filter(Boolean)
+        : scopes;
+  }
 
   result.url = urlBuilderAuthorize(`${baseUrl}/login/oauth/authorize`, result);
 
-  return result as Result<TClientType>;
+  return result;
 }
 
 function urlBuilderAuthorize(

src/types.ts

@@ -1,9 +1,9 @@
 export type ClientType = "oauth-app" | "github-app";
 
-export type OAuthAppOptions<TClientType extends "oauth-app"> = {
+export type OAuthAppOptions = {
   clientId: string;
 
-  clientType?: TClientType;
+  clientType?: "oauth-app";
   allowSignup?: boolean;
   login?: string;
   scopes?: string | string[];
@@ -12,51 +12,33 @@ export type OAuthAppOptions<TClientType extends "oauth-app"> = {
   baseUrl?: string;
 };
 
-export type GitHubAppOptions<TClientType extends "github-app"> = {
+export type GitHubAppOptions = {
   clientId: string;
 
-  clientType: TClientType;
-  /** `scopes` are not permitted for GitHub Apps */
-  scopes?: never;
+  clientType: "github-app";
   allowSignup?: boolean;
   login?: string;
   redirectUrl?: string;
   state?: string;
   baseUrl?: string;
 };
 
-export type Options<
-  TClientType extends ClientType
-> = TClientType extends "oauth-app"
-  ? OAuthAppOptions<TClientType>
-  : TClientType extends "github-app"
-  ? GitHubAppOptions<TClientType>
-  : never;
-
-type OAuthAppResult<TClientType extends "oauth-app"> = {
+export type OAuthAppResult = {
   allowSignup: boolean;
   clientId: string;
-  clientType: TClientType;
+  clientType: "oauth-app";
   login: string | null;
   redirectUrl: string | null;
   scopes: string[];
   state: string;
   url: string;
 };
-type GitHubAppResult<TClientType extends "github-app"> = {
+export type GitHubAppResult = {
   allowSignup: boolean;
   clientId: string;
-  clientType: TClientType;
+  clientType: "github-app";
   login: string | null;
   redirectUrl: string | null;
   state: string;
   url: string;
 };
-
-export type Result<
-  TClientType extends ClientType
-> = TClientType extends "oauth-app"
-  ? OAuthAppResult<TClientType>
-  : TClientType extends "github-app"
-  ? GitHubAppResult<TClientType>
-  : never;