From 8fac01bfa1a36989f621552fb2452a129b307d99 Mon Sep 17 00:00:00 2001
From: Bryan Jennings <bryanjenningz@gmail.com>
Date: Wed, 21 Sep 2022 03:18:31 -0700
Subject: [PATCH 1/2] Make DOJO exercises not nullable, fix React key bug

---
 graphql/index.tsx                | 8 ++++----
 graphql/typeDefs.ts              | 2 +-
 pages/exercises/[lessonSlug].tsx | 9 +++++----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/graphql/index.tsx b/graphql/index.tsx
index b0ad6227e..6c1436690 100644
--- a/graphql/index.tsx
+++ b/graphql/index.tsx
@@ -315,7 +315,7 @@ export type Query = {
   __typename?: 'Query'
   alerts: Array<Alert>
   allUsers?: Maybe<Array<Maybe<User>>>
-  exercises: Array<Maybe<Exercise>>
+  exercises: Array<Exercise>
   getLessonMentors?: Maybe<Array<Maybe<User>>>
   getPreviousSubmissions?: Maybe<Array<Submission>>
   isTokenValid: Scalars['Boolean']
@@ -838,7 +838,7 @@ export type GetExercisesQuery = {
       name: string
       lesson: { __typename?: 'Lesson'; slug: string }
     }
-  } | null>
+  }>
 }
 
 export type GetFlaggedExercisesQueryVariables = Exact<{ [key: string]: never }>
@@ -852,7 +852,7 @@ export type GetFlaggedExercisesQuery = {
       __typename?: 'Module'
       lesson: { __typename?: 'Lesson'; title: string }
     }
-  } | null>
+  }>
 }
 
 export type LessonMentorsQueryVariables = Exact<{
@@ -1780,7 +1780,7 @@ export type QueryResolvers<
     ContextType
   >
   exercises?: Resolver<
-    Array<Maybe<ResolversTypes['Exercise']>>,
+    Array<ResolversTypes['Exercise']>,
     ParentType,
     ContextType
   >
diff --git a/graphql/typeDefs.ts b/graphql/typeDefs.ts
index 26a9dc5b6..c02fb5d3e 100644
--- a/graphql/typeDefs.ts
+++ b/graphql/typeDefs.ts
@@ -6,7 +6,7 @@ export default gql`
     session: Session!
     allUsers: [User]
     modules: [Module]!
-    exercises: [Exercise]!
+    exercises: [Exercise!]!
     getLessonMentors(lessonId: Int!): [User]
     userInfo(username: String!): Session
     isTokenValid(cliToken: String!): Boolean!
diff --git a/pages/exercises/[lessonSlug].tsx b/pages/exercises/[lessonSlug].tsx
index 2f507fbf8..6992d03b0 100644
--- a/pages/exercises/[lessonSlug].tsx
+++ b/pages/exercises/[lessonSlug].tsx
@@ -54,10 +54,10 @@ const Exercises: React.FC<QueryDataProps<GetExercisesQuery>> = ({
   const currentExercises = exercises
     .filter(exercise => exercise?.module.lesson.slug === slug)
     .map(exercise => ({
-      challengeName: exercise?.module.name!,
-      problem: exercise?.description!,
-      answer: exercise?.answer!,
-      explanation: exercise?.explanation!
+      challengeName: exercise.module.name,
+      problem: exercise.description,
+      answer: exercise.answer,
+      explanation: exercise.explanation || ''
     }))
 
   const exercise = currentExercises[exerciseIndex]
@@ -66,6 +66,7 @@ const Exercises: React.FC<QueryDataProps<GetExercisesQuery>> = ({
     <Layout title={currentLesson.title}>
       {exercise ? (
         <Exercise
+          key={exerciseIndex}
           exercise={exercise}
           setExerciseIndex={setExerciseIndex}
           lessonTitle={currentLesson.title}

From 3a6f6a6128ab9f0c7104a3dfa3568a57109978cf Mon Sep 17 00:00:00 2001
From: Bryan Jennings <bryanjenningz@gmail.com>
Date: Wed, 21 Sep 2022 03:37:52 -0700
Subject: [PATCH 2/2] Make DOJO exercises tests pass after fixing React key bug

---
 __dummy__/getExercisesData.ts                  | 2 +-
 __tests__/pages/exercises/[lessonSlug].test.js | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/__dummy__/getExercisesData.ts b/__dummy__/getExercisesData.ts
index 4133d18ed..5f9c24e9c 100644
--- a/__dummy__/getExercisesData.ts
+++ b/__dummy__/getExercisesData.ts
@@ -87,7 +87,7 @@ const getExercisesData: GetExercisesQuery = {
       },
       description: '```\nlet a = 1\na -= 2\n// what is a?\n```',
       answer: '-1',
-      explanation: '`a -= 2` is a shorter way to write `a = a - 2`'
+      explanation: null
     }
   ]
 }
diff --git a/__tests__/pages/exercises/[lessonSlug].test.js b/__tests__/pages/exercises/[lessonSlug].test.js
index e00e1a890..95aac4afd 100644
--- a/__tests__/pages/exercises/[lessonSlug].test.js
+++ b/__tests__/pages/exercises/[lessonSlug].test.js
@@ -64,10 +64,11 @@ describe('Exercises page', () => {
     // Previous button is not in the document on the first exercise.
     expect(queryByRole('button', { name: 'PREVIOUS' })).not.toBeInTheDocument()
 
-    const skipButton = getByRole('button', { name: 'SKIP' })
+    let skipButton = getByRole('button', { name: 'SKIP' })
     fireEvent.click(skipButton)
     expect(queryByRole('button', { name: 'PREVIOUS' })).toBeInTheDocument()
 
+    skipButton = getByRole('button', { name: 'SKIP' })
     fireEvent.click(skipButton)
     // Skip button should not be in the document because we're on the last exercise now.
     expect(queryByRole('button', { name: 'SKIP' })).not.toBeInTheDocument()