Error codes

index.js

@@ -14,6 +14,27 @@ const fetch = require('node-fetch');
 const jwt = require('jsonwebtoken');
 const FormData = require('form-data');
 
+const MISSING_PARAMS = 'missing_params';
+const SIGN_FAILED = 'sign_failed';
+const REQUEST_FAILED = 'request_failed';
+const UNEXPECTED_RESPONSE_BODY = 'invalid_response_body';
+
+const throwRequestFailedError = details => {
+  const error = new Error(
+    `Request failed while swapping the jwt token. ${details}`
+  );
+  error.code = REQUEST_FAILED;
+  throw error;
+};
+
+const throwUnexpectedResponseError = details => {
+  const error = new Error(
+    `Unexpected response received while swapping the jwt token. ${details}`
+  );
+  error.code = UNEXPECTED_RESPONSE_BODY;
+  throw error;
+};
+
 async function authorize(options) {
   let {
     clientId,
@@ -34,9 +55,11 @@ async function authorize(options) {
   !privateKey ? errors.push('privateKey') : '';
   !metaScopes || metaScopes.length === 0 ? errors.push('metaScopes') : '';
   if (errors.length > 0) {
-    return Promise.reject(
-      new Error(`Required parameter(s) ${errors.join(', ')} are missing`)
+    const missingParamsError = new Error(
+      `Required parameter(s) ${errors.join(', ')} are missing`
     );
+    missingParamsError.code = MISSING_PARAMS;
+    throw missingParamsError;
   }
 
   if (metaScopes.constructor !== Array) {
@@ -66,7 +89,8 @@ async function authorize(options) {
       { algorithm: 'RS256' }
     );
   } catch (tokenError) {
-    return Promise.reject(tokenError);
+    tokenError.code = SIGN_FAILED;
+    throw tokenError;
   }
 
   const form = new FormData();
@@ -81,19 +105,24 @@ async function authorize(options) {
   };
 
   return fetch(`${ims}/ims/exchange/jwt/`, postOptions)
-    .then(res => res.json())
+    .catch(e => throwRequestFailedError(e.message))
+    .then(res => {
+      if (res.ok) {
+        return res.json();
+      } else {
+        throwRequestFailedError(res.statusText);
+      }
+    })
     .then(json => {
       const { access_token, error, error_description } = json;
       if (!access_token) {
         if (error && error_description) {
-          return Promise.reject(new Error(`${error}: ${error_description}`));
+          const swapError = new Error(error_description);
+          swapError.code = error;
+          throw swapError;
         } else {
-          return Promise.reject(
-            new Error(
-              `An unknown error occurred while swapping jwt. The response is as follows: ${JSON.stringify(
-                json
-              )}`
-            )
+          throwUnexpectedResponseError(
+            `The response body is as follows: ${JSON.stringify(json)}`
           );
         }
       }

test/auth.test.js

@@ -23,18 +23,34 @@ let mockResultSuccess = Promise.resolve({
   json: () =>
     Promise.resolve({ access_token: mockAccessToken, expires_in: 123456 })
 });
+// attempting to contact the API threw an error
+let mockEndpointFailure = Promise.reject(new Error('Endpoint error.'));
+// simple API failure
 let mockResultFailure = Promise.resolve({
   ok: false,
+  status: 400,
+  statusText: 'You did something wrong for the jwt exchange.',
   json: () =>
     Promise.resolve({
       error: 'my_error_code',
       error_description: 'This is the error description.'
     })
 });
-let mockResultFailureUnknown = Promise.resolve({
-  ok: false,
+// no access token, error, or error_description
+let mockResultFailureMalformedServerResponse = Promise.resolve({
+  ok: true,
+  status: 200,
   json: () => Promise.resolve({ foo: 'bar', baz: 'faz' })
 });
+let mockResultFailureNoJWT = Promise.resolve({
+  ok: true,
+  status: 200,
+  json: () =>
+    Promise.resolve({
+      error: 'my_error_code_no_jwt',
+      error_description: 'This is the error description. No JWT present.'
+    })
+});
 
 let fetch = require('node-fetch');
 jest.mock('node-fetch', () => jest.fn());
@@ -217,6 +233,23 @@ describe('Fetch jwt', () => {
     ).resolves.toEqual({ access_token: mockAccessToken, expires_in: 123456 });
   });
 
+  test('endpoint error thrown, unkown reason', () => {
+    expect.assertions(1);
+    fetch.mockImplementation(() => mockEndpointFailure);
+    return expect(
+      auth({
+        clientId,
+        clientSecret,
+        technicalAccountId,
+        orgId,
+        metaScopes,
+        privateKey
+      })
+    ).rejects.toThrow(
+      'Request failed while swapping the jwt token. Endpoint error.'
+    );
+  });
+
   test('invalid jwt, expected endpoint error', () => {
     expect.assertions(1);
     fetch.mockImplementation(() => mockResultFailure);
@@ -229,12 +262,33 @@ describe('Fetch jwt', () => {
         metaScopes,
         privateKey
       })
-    ).rejects.toThrow('my_error_code: This is the error description.');
+    ).rejects.toThrow(
+      'Request failed while swapping the jwt token. You did something wrong for the jwt exchange.'
+    );
+  });
+
+  test('malformed server response, dump entire json() call', () => {
+    expect.assertions(1);
+    fetch.mockImplementation(() => mockResultFailureMalformedServerResponse);
+    return expect(
+      auth({
+        clientId,
+        clientSecret,
+        technicalAccountId,
+        orgId,
+        metaScopes,
+        privateKey
+      })
+    ).rejects.toThrow(
+      new Error(
+        'Unexpected response received while swapping the jwt token. The response body is as follows: {"foo":"bar","baz":"faz"}'
+      )
+    );
   });
 
-  test('invalid jwt, unknown error', () => {
+  test('no access token, valid server response', () => {
     expect.assertions(1);
-    fetch.mockImplementation(() => mockResultFailureUnknown);
+    fetch.mockImplementation(() => mockResultFailureNoJWT);
     return expect(
       auth({
         clientId,
@@ -245,7 +299,7 @@ describe('Fetch jwt', () => {
         privateKey
       })
     ).rejects.toThrow(
-      'An unknown error occurred while swapping jwt. The response is as follows: {"foo":"bar","baz":"faz"}'
+      new Error('This is the error description. No JWT present.')
     );
   });
 });