Add duplicate modules conflict (#3738)

* Add duplicate modules conflict

Duplicate conflict checks if there are modules with the same module code added to the same academic year and semester.

* Add duplicate conflict message

* Format a line

Author: ChillinRage

website/src/selectors/planner.test.ts

@@ -10,6 +10,9 @@ import { State } from 'types/state';
 const CS1010X = clone(CS1010S);
 CS1010X.moduleCode = 'CS1010X';
 
+const CS3216_DUPLICATE = clone(CS3216);
+const CS1010S_DUPLICATE = clone(CS1010S);
+
 /* eslint-disable no-useless-computed-key */
 
 const defaultState: PlannerState = {
@@ -225,6 +228,98 @@ describe(getAcadYearModules, () => {
     ]);
   });
 
+  test('should return duplicate conflicts', () => {
+    const planner: PlannerState = {
+      ...defaultState,
+      modules: {
+        0: { id: '0', moduleCode: 'CS3216', year: '2018/2019', semester: 1, index: 0 },
+        1: { id: '1', moduleCode: 'CS3216', year: '2018/2019', semester: 1, index: 1 },
+        2: { id: '2', moduleCode: 'CS1010S', year: '2018/2019', semester: 2, index: 0 },
+        3: { id: '3', moduleCode: 'CS1010S', year: '2018/2019', semester: 2, index: 1 },
+      },
+    };
+
+    const moduleBank = {
+      modules: { CS3216, CS3216_DUPLICATE, CS1010S, CS1010S_DUPLICATE },
+      moduleCodes: {
+        CS3216: { semesters: [1] },
+        CS3216_clone: { semesters: [1] },
+        CS1010S: { semesters: [2] },
+        CS1010S_clone: { semesters: [2] },
+      },
+    };
+
+    const state: any = { planner, moduleBank };
+
+    expect(getAcadYearModules(state)).toHaveProperty('2018/2019.1', [
+      {
+        id: '0',
+        moduleCode: 'CS3216',
+        moduleInfo: CS3216,
+        conflict: { type: 'duplicate' },
+      },
+      {
+        id: '1',
+        moduleCode: 'CS3216',
+        moduleInfo: CS3216_DUPLICATE,
+        conflict: { type: 'duplicate' },
+      },
+    ]);
+
+    expect(getAcadYearModules(state)).toHaveProperty('2018/2019.2', [
+      {
+        id: '2',
+        moduleCode: 'CS1010S',
+        moduleInfo: CS1010S,
+        conflict: { type: 'duplicate' },
+      },
+      {
+        id: '3',
+        moduleCode: 'CS1010S',
+        moduleInfo: CS1010S_DUPLICATE,
+        conflict: { type: 'duplicate' },
+      },
+    ]);
+  });
+
+  test('should not have duplicate conflicts for same modules in different semesters', () => {
+    const planner: PlannerState = {
+      ...defaultState,
+      modules: {
+        0: { id: '0', moduleCode: 'CS1010S', year: '2018/2019', semester: 1, index: 0 },
+        1: { id: '1', moduleCode: 'CS1010S', year: '2018/2019', semester: 2, index: 0 },
+      },
+    };
+
+    const moduleBank = {
+      modules: { CS1010S, CS1010S_DUPLICATE },
+      moduleCodes: {
+        CS1010S: { semesters: [1, 2] },
+        CS1010S_clone: { semesters: [1, 2] },
+      },
+    };
+
+    const state: any = { planner, moduleBank };
+
+    expect(getAcadYearModules(state)).toHaveProperty('2018/2019.1', [
+      {
+        id: '0',
+        moduleCode: 'CS1010S',
+        moduleInfo: CS1010S,
+        conflict: null,
+      },
+    ]);
+
+    expect(getAcadYearModules(state)).toHaveProperty('2018/2019.2', [
+      {
+        id: '1',
+        moduleCode: 'CS1010S',
+        moduleInfo: CS1010S_DUPLICATE,
+        conflict: null,
+      },
+    ]);
+  });
+
   test('should not show exam conflicts for modules not taken this year', () => {
     const planner: PlannerState = {
       ...defaultState,

website/src/selectors/planner.ts

@@ -105,6 +105,16 @@ const examConflict =
     return null;
   };
 
+/**
+ * Checks if there are duplicate modules in one semester
+ */
+const duplicateConflict =
+  (moduleCodeMap: PlannerTime[]) =>
+  (moduleCode: ModuleCode): Conflict | null =>
+    moduleCodeMap.filter((module) => module.moduleCode === moduleCode).length === 1
+      ? null
+      : { type: 'duplicate' };
+
 function mapModuleToInfo(
   module: PlannerTime,
   modulesMap: ModulesMap,
@@ -224,6 +234,7 @@ export function getAcadYearModules(state: State): PlannerModulesWithInfo {
         noInfoConflict(moduleBank.moduleCodes, planner.custom),
         semesterConflict(moduleBank.moduleCodes, semester),
         examConflict(clashes),
+        duplicateConflict(moduleTimes),
       ];
 
       if (!planner.ignorePrereqCheck) {

website/src/types/planner.ts

@@ -30,7 +30,16 @@ export type NoInfo = {
   type: 'noInfo';
 };
 
-export type Conflict = PrereqConflict | ExamConflict | SemesterConflict | NoInfo;
+export type DuplicateConflict = {
+  type: 'duplicate';
+};
+
+export type Conflict =
+  | PrereqConflict
+  | ExamConflict
+  | SemesterConflict
+  | NoInfo
+  | DuplicateConflict;
 
 export type PlannerModulesWithInfo = {
   // Mapping acad years to a map of semester to module information object

website/src/views/planner/PlannerModule.tsx

@@ -104,6 +104,16 @@ const PlannerModule = memo<Props>((props) => {
           </>
         );
 
+      case 'duplicate':
+        return (
+          <>
+            <div className={styles.conflictHeader}>
+              <AlertTriangle className={styles.warningIcon} />
+              <p>This might be a duplicate of another course in this semester.</p>
+            </div>
+          </>
+        );
+
       default:
         return null;
     }