fix: answer range format validation and error message in Numerical input

src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/AnswerOption.jsx

@@ -18,6 +18,7 @@ import { FeedbackBox } from './components/Feedback';
 import * as hooks from './hooks';
 import { ProblemTypeKeys } from '../../../../../data/constants/problem';
 import ExpandableTextArea from '../../../../../sharedComponents/ExpandableTextArea';
+import { answerRangeFormatRegex } from '../../../data/OLXParser';
 
 const AnswerOption = ({
   answer,
@@ -48,6 +49,11 @@ const AnswerOption = ({
     ? `${getConfig().STUDIO_BASE_URL}/library_assets/blocks/${blockId}/`
     : undefined;
 
+  const validateAnswerRange = (value) => {
+    const cleanedValue = value.replace(/^\s+|\s+$/g, '');
+    return !cleanedValue.length || answerRangeFormatRegex.test(cleanedValue);
+  };
+
   const getInputArea = () => {
     if ([ProblemTypeKeys.SINGLESELECT, ProblemTypeKeys.MULTISELECT].includes(problemType)) {
       return (
@@ -77,8 +83,9 @@ const AnswerOption = ({
       );
     }
     // Return Answer Range View
+    const isValidValue = validateAnswerRange(answer.title);
     return (
-      <div>
+      <Form.Group isInvalid={!isValidValue}>
         <Form.Control
           as="textarea"
           className="answer-option-textarea text-gray-500 small"
@@ -88,10 +95,15 @@ const AnswerOption = ({
           onChange={setAnswerTitle}
           placeholder={intl.formatMessage(messages.answerRangeTextboxPlaceholder)}
         />
+        {!isValidValue && (
+          <Form.Control.Feedback type="invalid">
+            <FormattedMessage {...messages.answerRangeErrorText} />
+          </Form.Control.Feedback>
+        )}
         <div className="pgn__form-switch-helper-text">
           <FormattedMessage {...messages.answerRangeHelperText} />
         </div>
-      </div>
+      </Form.Group>
     );
   };
 

src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/messages.js

@@ -77,6 +77,11 @@ const messages = defineMessages({
     defaultMessage: 'Enter min and max values separated by a comma. Use a bracket to include the number next to it in the range, or a parenthesis to exclude the number. For example, to identify the correct answers as 5, 6, or 7, but not 8, specify [5,8).',
     description: 'Helper text describing usage of answer ranges',
   },
+  answerRangeErrorText: {
+    id: 'authoring.answerwidget.answer.answerRangeErrorText',
+    defaultMessage: 'Error: Invalid range format. Use brackets or parentheses with values separated by a comma.',
+    description: 'Error text describing wrong format of answer ranges',
+  },
 });
 
 export default messages;

src/editors/containers/ProblemEditor/data/OLXParser.js

@@ -57,6 +57,46 @@ export const responseKeys = [
   'choicetextresponse',
 ];
 
+/**
+ * Regular expression to validate numeric answer ranges in OLX format.
+ * Matches ranges in the form of (min, max) or [min, max] where:
+ * - Both min and max are required and can be:
+ *   - integers (e.g. 1, -5)
+ *   - decimals (e.g. 1.5, -0.25)
+ *   - fractions (e.g. 1/2, -3/4)
+ * - Whitespace around numbers and comma is optional
+ * - Parentheses () indicate exclusive bounds
+ * - Square brackets [] indicate inclusive bounds
+ *
+ * @example
+ * // Valid patterns:
+ * (1, 5)
+ * [1, 5]
+ * (1.5, 5.5)
+ * [-5, 10]
+ * (-3.5, 7)
+ * (-1,1)
+ * (-1,1]
+ * [-1,1)
+ * [1,1/2]
+ * [1/2, 2]
+ * [1/4, 1/2]
+ * (1,1/2]
+ * [1/2, 2)
+ * (1/4, 1/2)
+ *
+ * @example
+ * // Invalid patterns:
+ * (5,1)
+ * (1,)
+ * (,1)
+ * [1 5]
+ * {1,5}
+ * [--5,10]
+ * []
+ */
+export const answerRangeFormatRegex = /^[([]\s*-?(?:\d+(?:\.\d+)?|\d+\/\d+)\s*,\s*-?(?:\d+(?:\.\d+)?|\d+\/\d+)\s*[)\]]$/m;
+
 export const stripNonTextTags = ({ input, tag }) => {
   const stripedTags = {};
   Object.entries(input).forEach(([key, value]) => {

src/editors/containers/ProblemEditor/data/ReactStateOLXParser.js

@@ -407,23 +407,21 @@ class ReactStateOLXParser {
           let lowerBoundFraction;
           let upperBoundInt;
           let upperBoundFraction;
-          if (rawLowerBound.includes('/')) {
+          if (rawLowerBound?.includes('/')) {
             lowerBoundFraction = rawLowerBound.replace(/[^0-9-/]/gm, '');
             const [numerator, denominator] = lowerBoundFraction.split('/');
-            const lowerBoundFloat = Number(numerator) / Number(denominator);
-            lowerBoundInt = lowerBoundFloat;
+            lowerBoundInt = Number(numerator) / Number(denominator);
           } else {
-            // these regex replaces remove everything that is not a decimal or positive/negative numer
-            lowerBoundInt = Number(rawLowerBound.replace(/[^0-9-.]/gm, ''));
+            // these regex replaces remove everything that is not a decimal or positive/negative number
+            lowerBoundInt = Number(rawLowerBound?.replace(/[^0-9-.]/gm, ''));
           }
-          if (rawUpperBound.includes('/')) {
+          if (rawUpperBound?.includes('/')) {
             upperBoundFraction = rawUpperBound.replace(/[^0-9-/]/gm, '');
             const [numerator, denominator] = upperBoundFraction.split('/');
-            const upperBoundFloat = Number(numerator) / Number(denominator);
-            upperBoundInt = upperBoundFloat;
+            upperBoundInt = Number(numerator) / Number(denominator);
           } else {
-            // these regex replaces remove everything that is not a decimal or positive/negative numer
-            upperBoundInt = Number(rawUpperBound.replace(/[^0-9-.]/gm, ''));
+            // these regex replaces remove everything that is not a decimal or positive/negative number
+            upperBoundInt = Number(rawUpperBound?.replace(/[^0-9-.]/gm, ''));
           }
           if (lowerBoundInt > upperBoundInt) {
             const lowerBoundChar = rawUpperBound[rawUpperBound.length - 1] === ']' ? '[' : '(';

src/editors/containers/ProblemEditor/data/ReactStateOLXParser.test.js

@@ -18,6 +18,12 @@ import {
   numericInputWithAnswerRange,
   textInputWithFeedbackAndHintsWithMultipleAnswers,
   numberParseTest,
+  numericInputWithFractionBounds,
+  numericInputWithEmptyUpperBound,
+  numericInputWithSwappedBounds,
+  numericInputWithMissingLowerBound,
+  numericInputWithNegativeBounds,
+  numericInputWithSameBounds,
 } from './mockData/editorTestData';
 import ReactStateOLXParser from './ReactStateOLXParser';
 
@@ -147,4 +153,61 @@ describe('Check React State OLXParser problem', () => {
       );
     });
   });
+  describe('ReactStateOLXParser numerical response range parsing', () => {
+    test('handles empty upper bound as same as lower', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithEmptyUpperBound,
+        editorObject: numericInputWithEmptyUpperBound,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[0,1.5]');
+    });
+
+    test('handles swapped bounds and corrects order', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithSwappedBounds,
+        editorObject: numericInputWithSwappedBounds,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[2,5]');
+    });
+
+    test('fixes swapped fraction bounds and preserves brackets', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithFractionBounds,
+        editorObject: numericInputWithFractionBounds,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('(1/2,3/2)');
+    });
+
+    test('sets upper bound = lower bound if upper bound missing', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithMissingLowerBound,
+        editorObject: numericInputWithMissingLowerBound,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[,2.5]');
+    });
+
+    test('handles negative number ranges correctly', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithNegativeBounds,
+        editorObject: numericInputWithNegativeBounds,
+      });
+
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('(-5.5,-1)');
+    });
+
+    test('handles same numbers in ranges correctly', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithSameBounds,
+        editorObject: numericInputWithSameBounds,
+      });
+
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[10,10]');
+    });
+  });
 });

src/editors/containers/ProblemEditor/data/mockData/editorTestData.js

@@ -130,3 +130,75 @@ export const numberParseTest = {
   hints: [],
   question: '<p>What is the content of the register x2 after executing the following three lines of instructions?</p>',
 };
+
+export const numericInputWithEmptyUpperBound = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[1.5,]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithSwappedBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[5,2]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithFractionBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '(3/2,1/2)',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithMissingLowerBound = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[,2.5]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithNegativeBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '(-5.5,-1)',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithSameBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[10,10]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};