convert to typescript

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 package-lock.json
 .firebase/*
+**/*.d.ts

action.yml

@@ -3,7 +3,7 @@ description: "Firebase Hosting Preview"
 author: "Jason Miller (https://github.com/developit) and Firebase"
 runs:
   using: "node12"
-  main: "action.min.js"
+  main: "bin/action.min.js"
 inputs:
   repoToken:
     description: "The GITHUB_TOKEN secret"

package.json

@@ -1,22 +1,25 @@
 {
   "private": true,
   "name": "firebase-hosting-preview-action",
-  "main": "action.min.js",
-  "source": "index.js",
+  "main": "bin/action.min.js",
+  "source": "src/index.ts",
   "devDependencies": {
     "@actions/core": "^1.2.2",
     "@actions/exec": "^1.0.3",
     "@actions/github": "^2.1.1",
+    "@tsconfig/node12": "^1.0.7",
+    "@types/tmp": "^0.2.0",
     "husky": "^4.2.5",
     "microbundle": "^0.12.3",
     "prettier": "^2.1.0",
     "pretty-quick": "^3.0.0",
-    "tmp": "^0.2.1"
+    "tmp": "^0.2.1",
+    "typescript": "^4.0.2"
   },
   "scripts": {
     "format": "prettier --write .",
-    "build": "microbundle -f cjs --target node --compress --no-sourcemap index.js",
-    "build:watch": "microbundle watch -f cjs --target node --compress --no-sourcemap index.js"
+    "build": "microbundle -f cjs --target node --compress --no-sourcemap src/index.ts",
+    "build:watch": "microbundle watch -f cjs --target node --compress --no-sourcemap src/index.ts"
   },
   "husky": {
     "hooks": {

src/createCheck.ts

@@ -0,0 +1,22 @@
+import { GitHub } from "@actions/github";
+import { Context } from "@actions/github/lib/context";
+
+// create a check and return a function that updates (completes) it
+export async function createCheck(github: GitHub, context: Context) {
+  const check = await github.checks.create({
+    ...context.repo,
+    name: "Deploy Preview",
+    head_sha: context.payload.pull_request?.head.sha,
+    status: "in_progress",
+  });
+
+  return async (details: Object) => {
+    await github.checks.update({
+      ...context.repo,
+      check_run_id: check.data.id,
+      completed_at: new Date().toISOString(),
+      status: "completed",
+      ...details,
+    });
+  };
+}

src/createGACFile.ts

@@ -0,0 +1,12 @@
+import { fileSync } from "tmp";
+import { writeSync } from "fs";
+
+// Set up Google Application Credentials for use by the Firebase CLI
+// https://cloud.google.com/docs/authentication/production#finding_credentials_automatically
+export async function createGacFile(googleApplicationCredentials: string) {
+  const tmpFile = fileSync({ postfix: ".json" });
+
+  writeSync(tmpFile.fd, googleApplicationCredentials);
+
+  return tmpFile.name;
+}