feat: throw helpful error when appId or privateKey is set to a falsy value

src/index.ts

@@ -31,6 +31,18 @@ export {
 export const createAppAuth: StrategyInterface = function createAppAuth(
   options: StrategyOptions
 ) {
+  if (!options.appId) {
+    throw new Error("[@octokit/auth-app] appId option is required");
+  }
+  if (!options.privateKey) {
+    throw new Error("[@octokit/auth-app] privateKey option is required");
+  }
+  if ("installationId" in options && !options.installationId) {
+    throw new Error(
+      "[@octokit/auth-app] installationId is set to a falsy value"
+    );
+  }
+
   const log = Object.assign(
     {
       warn: console.warn.bind(console),

test/deprecations.test.ts

@@ -33,7 +33,7 @@ describe("deprecations", () => {
     const warn = jest.fn();
     const auth = createAppAuth({
       appId: "1",
-      privateKey: "",
+      privateKey: "1",
       clientId: "12345678901234567890",
       clientSecret: "1234567890123456789012345678901234567890",
       log: { warn },

test/index.test.ts

@@ -2135,3 +2135,33 @@ test("factory auth option", async () => {
     })
   );
 });
+
+it("throws helpful error if `appId` is not set properly (#184)", async () => {
+  expect(() => {
+    createAppAuth({
+      // @ts-ignore
+      appId: undefined,
+      privateKey: PRIVATE_KEY,
+    });
+  }).toThrowError("[@octokit/auth-app] appId option is required");
+});
+
+it("throws helpful error if `privateKey` is not set properly (#184)", async () => {
+  expect(() => {
+    createAppAuth({
+      appId: APP_ID,
+      // @ts-ignore
+      privateKey: undefined,
+    });
+  }).toThrowError("[@octokit/auth-app] privateKey option is required");
+});
+
+it("throws helpful error if `installationId` is set to a falsy value in createAppAuth() (#184)", async () => {
+  expect(() => {
+    createAppAuth({
+      appId: APP_ID,
+      privateKey: PRIVATE_KEY,
+      installationId: "",
+    });
+  }).toThrowError("[@octokit/auth-app] installationId is set to a falsy value");
+});