fixed bug with exercise indexing

src/haz3lweb/app/editors/mode/ExercisesMode.re

@@ -19,16 +19,18 @@ module Model = {
   };
 
   let persist = (~instructor_mode, model): persistent => {
-    cur_exercise: List.nth(model.exercises, model.current).editors.id,
-    exercise_data:
-      List.map(
-        (exercise: ExerciseMode.Model.t) =>
-          (
-            exercise.editors.id,
-            ExerciseMode.Model.persist(~instructor_mode, exercise),
-          ),
-        model.exercises,
-      ),
+    {
+      cur_exercise: List.nth(model.exercises, model.current).editors.id,
+      exercise_data:
+        List.map(
+          (exercise: ExerciseMode.Model.t) =>
+            (
+              exercise.editors.id,
+              ExerciseMode.Model.persist(~instructor_mode, exercise),
+            ),
+          model.exercises,
+        ),
+    };
   };
 
   let unpersist = (~instructor_mode, persistent: persistent) => {
@@ -464,18 +466,25 @@ module View = {
     @ EditorModeView.view(
         ~signal=
           fun
-          | Previous =>
-            inject(
-              Update.SwitchExercise(
-                abs((model.current - 1) mod List.length(model.exercises)),
-              ),
-            )
-          | Next =>
-            inject(
-              Update.SwitchExercise(
-                (model.current + 1) mod List.length(model.exercises),
-              ),
-            ),
+          | Previous => {
+              let next = model.current - 1;
+              let len = List.length(model.exercises);
+              print_endline("Length is: ");
+              print_endline(string_of_int((next mod len + len) mod len));
+              inject(
+                Update.SwitchExercise(
+                  // Ensures positive index
+                  (next mod len + len) mod len,
+                ),
+              );
+            }
+          | Next => {
+              inject(
+                Update.SwitchExercise(
+                  (model.current + 1) mod List.length(model.exercises),
+                ),
+              );
+            },
         ~indicator=
           EditorModeView.indicator_n(
             model.current,

src/haz3lweb/exercises/Exercise.re

@@ -129,6 +129,8 @@ type persistent_state = {
   point_distribution,
   required: int,
   module_name: string,
+  syntax_tests: list(syntax_test),
+  hidden_test_hints: list(string),
   // NOTE: Add new fields to record here as new instructor editable features are
   //       implemented (eg. prelude: PersistentZipper.t when adding the feature
   //       to edit the prelude). After adding these field(s), we will need to
@@ -784,6 +786,8 @@ let persist = (state: state, ~instructor_mode: bool) => {
     point_distribution: state.eds.point_distribution,
     required: state.eds.your_tests.required,
     module_name: state.eds.module_name,
+    syntax_tests: state.eds.syntax_tests,
+    hidden_test_hints: state.eds.hidden_tests.hints,
   };
 };
 
@@ -797,6 +801,8 @@ let unpersist =
         point_distribution,
         required,
         module_name,
+        syntax_tests,
+        hidden_test_hints,
       }: persistent_state,
       ~spec: spec,
       ~instructor_mode: bool,
@@ -839,9 +845,9 @@ let unpersist =
       hidden_bugs,
       hidden_tests: {
         tests: hidden_tests_tests,
-        hints: spec.hidden_tests.hints,
+        hints: hidden_test_hints,
       },
-      syntax_tests: spec.syntax_tests,
+      syntax_tests,
     },
   };
 };