From e0dc8947742e616294994cb6ddb786d42ca30a43 Mon Sep 17 00:00:00 2001
From: Oscar Dominguez <dominguez.celada@gmail.com>
Date: Sun, 1 Aug 2021 22:41:55 +0200
Subject: [PATCH] feat(get-app-authentication): improve error message when
 privateKey is incomplete (#312)

---
 src/get-app-authentication.ts | 32 +++++++++++++++++++++-----------
 test/index.test.ts            | 22 ++++++++++++++++++++++
 2 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/src/get-app-authentication.ts b/src/get-app-authentication.ts
index 81274ffe8..3fad21b65 100644
--- a/src/get-app-authentication.ts
+++ b/src/get-app-authentication.ts
@@ -7,16 +7,26 @@ export async function getAppAuthentication({
   privateKey,
   timeDifference,
 }: State & { timeDifference?: number }): Promise<AppAuthentication> {
-  const appAuthentication = await githubAppJwt({
-    id: +appId,
-    privateKey,
-    now: timeDifference && Math.floor(Date.now() / 1000) + timeDifference,
-  });
+  try {
+    const appAuthentication = await githubAppJwt({
+      id: +appId,
+      privateKey,
+      now: timeDifference && Math.floor(Date.now() / 1000) + timeDifference,
+    });
 
-  return {
-    type: "app",
-    token: appAuthentication.token,
-    appId: appAuthentication.appId,
-    expiresAt: new Date(appAuthentication.expiration * 1000).toISOString(),
-  };
+    return {
+      type: "app",
+      token: appAuthentication.token,
+      appId: appAuthentication.appId,
+      expiresAt: new Date(appAuthentication.expiration * 1000).toISOString(),
+    };
+  } catch (error) {
+    if (privateKey === "-----BEGIN RSA PRIVATE KEY-----") {
+      throw new Error(
+        "The 'privateKey` option contains only the first line '-----BEGIN RSA PRIVATE KEY-----'. If you are setting it using a `.env` file, make sure it is set on a single line with newlines replaced by '\n'"
+      );
+    } else {
+      throw error;
+    }
+  }
 }
diff --git a/test/index.test.ts b/test/index.test.ts
index 240e39266..8fe46b1cf 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -93,6 +93,28 @@ test("throws if invalid 'type' is provided", async () => {
   );
 });
 
+test("throws if invalid Private Key is provided", async () => {
+  const auth = createAppAuth({
+    appId: APP_ID,
+    privateKey: "INVALID_PRIVATE_KEY",
+  });
+
+  await expect(auth({ type: "app" })).rejects.toEqual(expect.anything());
+});
+
+test("throws if incomplete Private Key is provided", async () => {
+  const auth = createAppAuth({
+    appId: APP_ID,
+    privateKey: "-----BEGIN RSA PRIVATE KEY-----",
+  });
+
+  await expect(auth({ type: "app" })).rejects.toEqual(
+    new Error(
+      "The 'privateKey` option contains only the first line '-----BEGIN RSA PRIVATE KEY-----'. If you are setting it using a `.env` file, make sure it is set on a single line with newlines replaced by '\n'"
+    )
+  );
+});
+
 test("README example for installation auth", async () => {
   const matchCreateInstallationAccessToken: MockMatcherFunction = (
     url,