chore: use octokit-from-auth package (#437)

## PR Checklist

- [x] Addresses an existing open issue: fixes #436
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/github-username-to-emails/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/github-username-to-emails/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Replaces the equivalent logic internally.

💖

README.md

@@ -64,7 +64,7 @@ Only publicly visible emails can be retrieved.
 
 ### Options
 
-`auth` is retrieved with [`get-github-auth-token`](https://github.com/JoshuaKGoldberg/get-github-auth-token), which defaults to `process.env.GH_TOKEN`, or failing that, [`gh auth token`](https://cli.github.com/manual/gh_auth_token).
+`auth` is retrieved with [`octokit-from-auth`](https://github.com/JoshuaKGoldberg/octokit-from-auth), which defaults to `process.env.GH_TOKEN`, or failing that, [`gh auth token`](https://cli.github.com/manual/gh_auth_token).
 If neither is available then an auth token must be provided as an option.
 
 | Option         | Type     | Description                        | Default                                      |

package.json

@@ -39,8 +39,8 @@
 		"*": "prettier --ignore-unknown --write"
 	},
 	"dependencies": {
-		"get-github-auth-token": "^0.1.0",
-		"octokit": "^4.0.0"
+		"octokit": "^4.0.2",
+		"octokit-from-auth": "^0.2.0"
 	},
 	"devDependencies": {
 		"@release-it/conventional-changelog": "^9.0.0",

src/getGitHubUsernameEmails.test.ts

@@ -2,18 +2,11 @@ import { describe, expect, it, vi } from "vitest";
 
 import { getGitHubUsernameEmails } from "./getGitHubUsernameEmails.js";
 
-const mockGetGitHubAuthToken = vi.fn();
-
-vi.mock("get-github-auth-token", () => ({
-	get getGitHubAuthToken() {
-		return mockGetGitHubAuthToken;
-	},
-}));
-
-vi.mock("octokit", () => ({
-	Octokit: class MockOctokit {
-		request = vi.fn();
-	},
+vi.mock("octokit-from-auth", () => ({
+	octokitFromAuth: () =>
+		Promise.resolve({
+			request: vi.fn(),
+		}),
 }));
 
 vi.mock("./getAccountEmail.js", () => ({
@@ -27,38 +20,7 @@ vi.mock("./getEventsEmails.js", () => ({
 const username = "abc123";
 
 describe("getGitHubUsernameEmails", () => {
-	it("throws an error when no auth is provided or available", async () => {
-		mockGetGitHubAuthToken.mockResolvedValue({
-			succeeded: false,
-			token: "gho_def456",
-		});
-
-		await expect(
-			async () => await getGitHubUsernameEmails({ username }),
-		).rejects.toMatchInlineSnapshot(
-			`[Error: Please provide an auth token (process.env.GH_TOKEN) or log in with the GitHub CLI (gh).]`,
-		);
-	});
-
-	it("throws an error an empty auth is provided", async () => {
-		mockGetGitHubAuthToken.mockResolvedValue({
-			succeeded: true,
-			token: "gho_def456",
-		});
-
-		await expect(
-			async () => await getGitHubUsernameEmails({ auth: "", username }),
-		).rejects.toMatchInlineSnapshot(
-			`[Error: Invalid auth provided: an empty string ('').]`,
-		);
-	});
-
-	it("returns account and events emails when getGitHubAuthToken auth is valid", async () => {
-		mockGetGitHubAuthToken.mockResolvedValue({
-			succeeded: true,
-			token: "gho_def456",
-		});
-
+	it("returns account and events emails", async () => {
 		const actual = await getGitHubUsernameEmails({ username });
 
 		expect(actual).toMatchInlineSnapshot(`

src/getGitHubUsernameEmails.ts

@@ -1,5 +1,4 @@
-import { getGitHubAuthToken } from "get-github-auth-token";
-import { Octokit } from "octokit";
+import { octokitFromAuth } from "octokit-from-auth";
 
 import { getAccountEmail } from "./getAccountEmail.js";
 import { getEventsEmails } from "./getEventsEmails.js";
@@ -15,31 +14,12 @@ export interface GitHubUsernameEmails {
 	events: EmailsToNames;
 }
 
-async function retrieveAuth(provided: string | undefined) {
-	if (provided === "") {
-		throw new Error("Invalid auth provided: an empty string ('').");
-	}
-
-	const auth = await getGitHubAuthToken();
-	if (auth.succeeded) {
-		return auth.token;
-	}
-
-	throw new Error(
-		"Please provide an auth token (process.env.GH_TOKEN) or log in with the GitHub CLI (gh).",
-		{
-			cause: auth.error,
-		},
-	);
-}
-
 export async function getGitHubUsernameEmails({
-	auth: providedAuth,
+	auth,
 	...rawOptions
 }: GitHubUsernameEmailsOptions): Promise<GitHubUsernameEmails> {
-	const auth = await retrieveAuth(providedAuth);
+	const octokit = await octokitFromAuth({ auth });
 
-	const octokit = new Octokit({ auth });
 	const options = { ...defaultOptions, ...rawOptions };
 
 	return {