Reopen a Text entry answer of NULL as authored

contentcuration/contentcuration/frontend/shared/views/QTIEditor/__tests__/validateItem.spec.js

@@ -1,6 +1,7 @@
 import { validateItemShape, validateQtiItem } from '../validateItem';
 import { QuestionType, ValidationError } from '../constants';
 import { assembleItemXml } from '../serialization/assembleItem';
+import { parseItem } from '../serialization/parseItem';
 import { textEntryInteractionDescriptor } from '../interactions/textEntry/Descriptor';
 import { validateTextEntryInteraction } from '../interactions/textEntry/validation';
 import {
@@ -174,6 +175,27 @@ describe('validateQtiItem', () => {
     });
   });
 
+  describe('text entry answers', () => {
+    it.each([false, true])('reopens and accepts NULL with caseSensitive %s', caseSensitive => {
+      const { bodyXml, responseDeclarations } = textEntryInteractionDescriptor.buildXML(
+        {
+          prompt: '<p>Which SQL keyword marks a missing value?</p>',
+          answers: [{ id: 'a0', value: 'NULL', caseSensitive }],
+          expectedLength: 0,
+        },
+        QuestionType.TEXT_ENTRY,
+      );
+      const xml = assembleItemXml({ identifier: 'item', title: '', bodyXml, responseDeclarations });
+      const [interaction] = parseItem(xml).interactions;
+
+      expect(validateQtiItem(xml)).toEqual([]);
+      expect(
+        textEntryInteractionDescriptor.parse(interaction.bodyXml, interaction.responseDeclarations)
+          .answers,
+      ).toEqual([{ id: expect.any(String), value: 'NULL', caseSensitive }]);
+    });
+  });
+
   it('reports unparseable XML', () => {
     expect(validateQtiItem('<qti-assessment-item><oops>')).toEqual([
       { code: ValidationError.PARSE_ERROR },

contentcuration/contentcuration/frontend/shared/views/QTIEditor/interactions/textEntry/__tests__/parse.spec.js

@@ -344,7 +344,7 @@ describe('_extractAnswers', () => {
       expect(errorSpy).toHaveBeenCalled();
     });
 
-    it.each(['1,234', '1.2.3', '1e400', 'Infinity', '0x10', '', 'NULL'])(
+    it.each(['1,234', '1.2.3', '1e400', 'Infinity', '0x10', ''])(
       'reads answers past default value %j, which fromXML accepts',
       defaultValue => {
         const declXml = `

contentcuration/contentcuration/frontend/shared/views/QTIEditor/serialization/qti/QTIDeclaration.js

@@ -202,7 +202,7 @@ export class QTIDeclaration {
    *
    * Follows the Kolibri QTI implementation — each base-type maps to a
    * specific JS primitive or 2-element array (point/pair/directedPair).
-   * Returns null for empty, null, undefined, or 'NULL' inputs.
+   * Returns null for empty, null, or undefined inputs.
    *
    * @param {string|null|undefined} raw  - Raw text from a <qti-value> element
    * @param {string|null}           baseType - One of BaseType.* constants
@@ -211,7 +211,7 @@ export class QTIDeclaration {
    */
   static coerceValue(raw, baseType) {
     // QTI treats empty / null as NULL — see qti-is-null spec
-    if (raw === null || raw === undefined || raw === '' || raw === 'NULL') {
+    if (raw === null || raw === undefined || raw === '') {
       return null;
     }
 

contentcuration/contentcuration/frontend/shared/views/QTIEditor/serialization/qti/__tests__/QTIDeclaration.spec.js

@@ -322,9 +322,13 @@ describe('QTIDeclaration full XML output (QTI compatibility)', () => {
 
 describe('QTIDeclaration.coerceValue', () => {
   describe('null / empty handling', () => {
-    it.each([null, undefined, '', 'NULL'])('returns null for %p', raw => {
+    it.each([null, undefined, ''])('returns null for %p', raw => {
       expect(QTIDeclaration.coerceValue(raw, 'identifier')).toBeNull();
     });
+
+    it('keeps the string "NULL"', () => {
+      expect(QTIDeclaration.coerceValue('NULL', 'string')).toBe('NULL');
+    });
   });
 
   describe('boolean', () => {