feat!: Initial v2 commit

* Implemented editorconfig
* Switched to ESM
* Switched to a TypeScript workflow
* Switched to projen for project management
* Major code refactor
* TODO: need tests

src/cleanup/index.ts

@@ -0,0 +1,35 @@
+import * as url from 'node:url';
+import * as core from '@actions/core';
+import { errorMessage } from '../helpers.js';
+
+/**
+ * When the GitHub Actions job is done, clean up any environment variables that
+ * may have been set by the configure-aws-credentials steps in the job.
+ *
+ * Environment variables are not intended to be shared across different jobs in
+ * the same GitHub Actions workflow: GitHub Actions documentation states that
+ * each job runs in a fresh instance.  However, doing our own cleanup will
+ * give us additional assurance that these environment variables are not shared
+ * with any other jobs.
+ */
+
+export async function cleanup() {
+  try {
+    // The GitHub Actions toolkit does not have an option to completely unset
+    // environment variables, so we overwrite the current value with an empty
+    // string. The AWS CLI and AWS SDKs will behave correctly: they treat an
+    // empty string value as if the environment variable does not exist.
+    core.exportVariable('AWS_ACCESS_KEY_ID', '');
+    core.exportVariable('AWS_SECRET_ACCESS_KEY', '');
+    core.exportVariable('AWS_SESSION_TOKEN', '');
+    core.exportVariable('AWS_DEFAULT_REGION', '');
+    core.exportVariable('AWS_REGION', '');
+  } catch (error) {
+    core.setFailed(errorMessage(error));
+  }
+}
+
+const modulePath = url.fileURLToPath(import.meta.url);
+if (process.argv[1] === modulePath) {
+  await cleanup();
+}