feat: add findEmails utility function

.eslintignore

@@ -0,0 +1 @@
+/dist

.gitignore

@@ -12,3 +12,6 @@ node_modules
 
 # ESLint
 .eslintcache
+
+# Build output
+/dist

.prettierignore

@@ -1,2 +1,3 @@
+/dist
 .eslintcache
 pnpm-lock.yaml

README.md

@@ -3,14 +3,30 @@
 [![npm](https://img.shields.io/npm/v/find-gh-commit-emails/latest)](https://www.npmjs.com/package/find-gh-commit-emails)
 [![license: MIT](https://img.shields.io/npm/l/find-gh-commit-emails)](https://github.com/reifiedbeans/find-gh-commit-emails/blob/main/LICENSE)
 
-A script to search for emails used by a given GitHub user.
+Utilities for finding emails used by a given GitHub user.
 
 ## Usage
 
+This package provides an executable that can be invoked directly.
+
 ```shell
 npx find-gh-commit-emails <username>
 ```
 
+A utility function is also provided for use in Node.js applications.
+
+```javascript
+import { findEmails } from "find-gh-commit-emails";
+
+const username = "<username>";
+const token = "[token]";
+const options = {
+  includeCommitter: true,
+};
+
+const emailMap = await findEmails(username, token, options);
+```
+
 ## License
 
 Licensed under the [MIT License](https://github.com/reifiedbeans/find-gh-commit-emails/blob/main/LICENSE).

bin/cli.ts

@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+import { program } from "@commander-js/extra-typings";
+import { findEmails } from "../lib/index.ts";
+
+program
+  .name("find-gh-commit-emails")
+  .description(
+    "Search for emails used by a given GitHub user. " +
+      "Setting the GITHUB_TOKEN environment variable to a valid GitHub personal " +
+      "access token will enable searching in non-public repositories.",
+  )
+  .argument("username", "GitHub username to find emails for")
+  .option("--include-committer", "include committer email in results", false)
+  .configureHelp({ helpWidth: 80 })
+  .showHelpAfterError()
+  .action(async (username, opts) => {
+    const token = process.env["GITHUB_TOKEN"];
+    const emailsMap = await findEmails(username, token, opts);
+    console.log(JSON.stringify(emailsMap, null, 2));
+  });
+
+program.parse(process.argv);

lib/index.ts

@@ -0,0 +1,51 @@
+import { Octokit } from "octokit";
+
+interface Options {
+  readonly includeCommitter?: boolean;
+}
+
+/**
+ * Find emails for a GitHub user
+ * @param username a GitHub username
+ * @param token a GitHub token
+ * @param opts additional options
+ */
+export async function findEmails(
+  username: string,
+  token?: string,
+  opts?: Options,
+) {
+  const github = new Octokit({ auth: token });
+
+  const commitData = await github.paginate("GET /search/commits", {
+    q: `author:${username}`,
+  });
+
+  const emailMap = new Map<string, Set<string>>();
+
+  for (const entry of commitData) {
+    const repo = entry.repository.full_name;
+    const emails = [entry.commit.author.email];
+
+    if (opts?.includeCommitter && entry.commit.committer?.email) {
+      emails.push(entry.commit.committer.email);
+    }
+
+    for (const email of emails) {
+      let repos = emailMap.get(email);
+      if (!repos) {
+        repos = new Set();
+        emailMap.set(email, repos);
+      }
+      repos.add(repo);
+    }
+  }
+
+  const object: { [key: string]: string[] } = {};
+  for (const [email, repos] of emailMap) {
+    Object.assign(object, {
+      [email]: Array.from(repos),
+    });
+  }
+  return object;
+}

package.json

@@ -9,23 +9,26 @@
   "license": "MIT",
   "type": "module",
   "files": [
-    "index.js"
+    "dist"
   ],
+  "main": "dist/lib/index.js",
+  "types": "dist/lib/index.d.ts",
   "bin": {
-    "find-gh-commit-emails": "index.js"
+    "find-gh-commit-emails": "dist/bin/cli.js"
   },
   "engines": {
     "node": ">=18"
   },
   "scripts": {
+    "build": "tsup",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
-    "lint": "eslint --cache --max-warnings=0 .",
-    "lint:fix": "eslint --fix --cache --max-warnings=0 .",
-    "prepack": "npm-run-all lint format:check"
+    "lint": "tsc && eslint --cache --max-warnings=0 .",
+    "lint:fix": "tsc && eslint --fix --cache --max-warnings=0 .",
+    "prepack": "npm-run-all build lint format:check"
   },
   "dependencies": {
-    "commander": "^12.1.0",
+    "@commander-js/extra-typings": "^12.1.0",
     "octokit": "^4.0.2"
   },
   "devDependencies": {
@@ -36,7 +39,9 @@
     "eslint": "^8.57.0",
     "eslint-config-prettier": "^9.1.0",
     "npm-run-all": "^4.1.5",
-    "prettier": "^3.3.2"
+    "prettier": "^3.3.2",
+    "tsup": "^8.1.0",
+    "typescript": "^5.5.3"
   },
   "publishConfig": {
     "access": "public"