feat: implement the action in typescript

src/login.ts

@@ -0,0 +1,28 @@
+import { mkdir, writeFile } from 'node:fs/promises'
+import { join } from 'node:path'
+import { env } from 'node:process'
+
+import { debug, getInput, saveState, setFailed } from '@actions/core'
+
+export async function setupKubeconfig() {
+	debug('Running kubectl-action setupKubeconfig()')
+
+	if (env.HOME === undefined) {
+		setFailed('$HOME is not defined')
+		return
+	}
+
+	const config = getInput('base64-kube-config', {
+		required: true,
+		trimWhitespace: true
+	})
+
+	const decoded = Buffer.from(config, 'base64')
+		.toString('utf8')
+
+	const path = join(env.HOME, '.kube')
+	saveState('kubeconfig-path', path)
+
+	await mkdir(path, { recursive: true })
+	await writeFile(join(path, 'config'), decoded, 'utf8')
+}