#2970: autoGen-talawa-admin-docs-debugging

src/utils/StaticMockLink.ts

@@ -23,6 +23,10 @@ function requestToKey(request: any, addTypename: boolean): string {
   return JSON.stringify(requestKey);
 }
 
+/**
+ * Similar to the standard Apollo MockLink, but doesn't consume a mock
+ * when it is used allowing it to be used in places like Storybook.
+ */
 export class StaticMockLink extends ApolloLink {
   public operation?: Operation;
   public addTypename = true;
@@ -69,37 +73,63 @@ export class StaticMockLink extends ApolloLink {
       },
     );
 
+    let configError: Error;
+
     if (!response || typeof responseIndex === 'undefined') {
-      return new Observable((observer) => {
-        const error = new Error(
-          `No more mocked responses for the query: ${print(
-            operation.query,
-          )}, variables: ${JSON.stringify(operation.variables)}`,
+      configError = new Error(
+        `No more mocked responses for the query: ${print(
+          operation.query,
+        )}, variables: ${JSON.stringify(operation.variables)}`,
+      );
+    } else {
+      const { newData } = response;
+      if (newData) {
+        response.result = newData(operation.variables);
+        this._mockedResponsesByKey[key].push(response);
+      }
+
+      if (!response.result && !response.error) {
+        configError = new Error(
+          `Mocked response should contain either result or error: ${key}`,
         );
-        observer.error(error);
-      });
+      }
     }
 
     return new Observable((observer) => {
-      const timer = setTimeout(() => {
-        if (response.error) {
-          observer.error(response.error);
-        } else if (response.result) {
-          observer.next(
-            typeof response.result === 'function'
-              ? (response.result as ResultFunction<FetchResult>)(
-                  operation.variables,
-                )
-              : response.result,
-          );
-          observer.complete();
-        } else {
-          const error = new Error(
-            `Mocked response should contain either result or error: ${key}`,
-          );
-          observer.error(error);
-        }
-      }, response.delay || 50); // Default delay of 50ms
+      const timer = setTimeout(
+        () => {
+          if (configError) {
+            try {
+              // The onError function can return false to indicate that
+              // configError need not be passed to observer.error. For
+              // example, the default implementation of onError calls
+              // observer.error(configError) and then returns false to
+              // prevent this extra (harmless) observer.error call.
+              if (this.onError(configError, observer) !== false) {
+                throw configError;
+              }
+            } catch (error) {
+              observer.error(error);
+            }
+          } else if (response) {
+            if (response.error) {
+              observer.error(response.error);
+            } else {
+              if (response.result) {
+                observer.next(
+                  typeof response.result === 'function'
+                    ? (response.result as ResultFunction<FetchResult>)(
+                        operation.variables,
+                      )
+                    : response.result,
+                );
+              }
+              observer.complete();
+            }
+          }
+        },
+        (response && response.delay) || 0,
+      );
 
       return () => {
         clearTimeout(timer);
@@ -128,10 +158,14 @@ export interface InterfaceMockApolloLink extends ApolloLink {
   operation?: Operation;
 }
 
-// Function to mock a single link
+// Pass in multiple mocked responses, so that you can test flows that end up
+// making multiple queries to the server.
+// NOTE: The last arg can optionally be an `addTypename` arg.
 export function mockSingleLink(
   ...mockedResponses: any[]
 ): InterfaceMockApolloLink {
+  // To pull off the potential typename. If this isn't a boolean, we'll just
+  // set it true later.
   let maybeTypename = mockedResponses[mockedResponses.length - 1];
   let mocks = mockedResponses.slice(0, mockedResponses.length - 1);