Add timeout value and status code to TimeoutError

__tests__/timeoutLink.test.ts

@@ -55,7 +55,9 @@ test('long request times out', done => {
       done();
     },
     error(error) {
-      expect(error.message).toBe('Timeout exceeded');
+      expect(error.message).toEqual('Timeout exceeded');
+      expect(error.timeout).toEqual(100);
+      expect(error.statusCode).toEqual(408);
       done();
     }
   });

src/TimeoutError.ts

@@ -1 +1,10 @@
-export default class TimeoutError extends Error {}
+export default class TimeoutError extends Error {
+  public timeout: number;
+  public statusCode: number;
+
+  constructor(message: string, timeout?: number, statusCode?: number) {
+    super(message);
+    this.timeout = timeout;
+    this.statusCode = statusCode || 408;
+  }
+}

src/timeoutLink.ts

@@ -17,13 +17,9 @@ export default class TimeoutLink extends ApolloLink {
 
   public request(operation: Operation, forward: NextLink) {
     let controller: AbortController;
-    let ctxTimeout: number;
 
     // override timeout from query context
-    ctxTimeout = operation.getContext().timeout || null;
-    if (ctxTimeout <= 0) {
-      ctxTimeout = null;
-    }
+    const requestTimeout = operation.getContext().timeout || this.timeout;
 
     // add abort controller and signal object to fetchOptions if they don't already exist
     if (typeof AbortController !== 'undefined') {
@@ -42,14 +38,14 @@ export default class TimeoutLink extends ApolloLink {
       (def: DefinitionNode) => def.kind === 'OperationDefinition'
     ).operation;
 
-    if (this.timeout <= 0 || operationType === 'subscription') {
+    if (requestTimeout <= 0 || operationType === 'subscription') {
       return chainObservable; // skip this link if timeout is zero or it's a subscription request
     }
 
     // create local observable with timeout functionality (unsubscibe from chain observable and
     // return an error if the timeout expires before chain observable resolves)
     const localObservable = new Observable(observer => {
-      let timer: NodeJS.Timer;
+      let timer: number;
 
       // listen to chainObservable for result and pass to localObservable if received before timeout
       const subscription = chainObservable.subscribe(
@@ -66,14 +62,14 @@ export default class TimeoutLink extends ApolloLink {
       );
 
       // if timeout expires before observable completes, abort call, unsubscribe, and return error
-      timer = setTimeout(() => {
+      timer = window.setTimeout(() => {
         if (controller) {
           controller.abort(); // abort fetch operation
         }
 
-        observer.error(new TimeoutError('Timeout exceeded'));
+        observer.error(new TimeoutError('Timeout exceeded', requestTimeout));
         subscription.unsubscribe();
-      }, ctxTimeout || this.timeout);
+      }, requestTimeout);
 
       let ctxRef = operation.getContext().timeoutRef;