Fix node value when empty tag attributes is given

__test__/converters/mathml-string-to-mathml-interfaces/MathMLStringToMathMLInterfaces.test.ts

@@ -1,5 +1,11 @@
 import { MathMLStringToMathMLInterfaces } from '../../../src/converters/mathml-string-to-mathml-interfaces';
-import { singleMi, singleMiNoRoot } from '../../mocks/mathmlStrings';
+import {
+  singleMi,
+  singleMiNoRoot,
+  mrow,
+  mfencedWithSeparatorAttribute,
+  mfencedWithBrokenAttribute,
+} from '../../mocks/mathmlStrings';
 
 describe('#convert', () => {
   describe('given math string with mi tag', () => {
@@ -21,7 +27,7 @@ describe('#convert', () => {
   describe('given math tag outside any other tag', () => {
     test('return array with single mathml interface of name math and child mi', () => {
       const mathmlString = singleMiNoRoot;
-    
+
       const result = new MathMLStringToMathMLInterfaces(mathmlString).convert();
 
       expect(result.length).toBe(1);
@@ -33,4 +39,81 @@ describe('#convert', () => {
       });
     });
   });
+
+  describe('given math string with nested tags', () => {
+    test('return content in a three and keep value on each child', () => {
+      const mathmlString = mrow;
+
+      const result = new MathMLStringToMathMLInterfaces(mathmlString).convert();
+
+      expect(result.length).toBe(1);
+      expect(result[0]).toMatchObject({
+        attributes: {},
+        children: [
+          {
+            attributes: {},
+            children: [
+              { attributes: {}, children: [], name: 'mn', value: '2' },
+              { attributes: {}, children: [], name: 'mo', value: '+' },
+              { attributes: {}, children: [], name: 'mn', value: '2' },
+            ],
+            name: 'mrow',
+            value: '',
+          },
+        ],
+        name: 'math',
+        value: '',
+      });
+    });
+  });
+
+  describe("given math string with mfenced with three contents with separator attribute ';;;'", () => {
+    test('add attributes to children related with name mfenced', () => {
+      const mathmlString = mfencedWithSeparatorAttribute;
+
+      const result = new MathMLStringToMathMLInterfaces(mathmlString).convert();
+
+      expect(result.length).toBe(1);
+      expect(result[0]).toMatchObject({
+        attributes: {},
+        children: [
+          {
+            attributes: { separators: ';;;' },
+            children: [
+              { attributes: {}, children: [], name: 'mn', value: '3' },
+              { attributes: {}, children: [], name: 'mn', value: '2' },
+              { attributes: {}, children: [], name: 'mn', value: '1' },
+            ],
+            name: 'mfenced',
+            value: '',
+          },
+        ],
+        name: 'math',
+        value: '',
+      });
+    });
+  });
+
+  describe('given math string with mfenced with single content, open attr settled as { and void close tag', () => {
+    test('add attributes to children related with name mfenced', () => {
+      const mathmlString = mfencedWithBrokenAttribute;
+
+      const result = new MathMLStringToMathMLInterfaces(mathmlString).convert();
+
+      expect(result.length).toBe(1);
+      expect(result[0]).toMatchObject({
+        attributes: {},
+        children: [
+          {
+            attributes: { open: '{', close: '' },
+            children: [{ attributes: {}, children: [], name: 'mn', value: '3' }],
+            name: 'mfenced',
+            value: '',
+          },
+        ],
+        name: 'math',
+        value: '',
+      });
+    });
+  });
 });

__test__/mocks/mathmlStrings.ts

@@ -1,3 +1,37 @@
 export const singleMi = '<root><math><mi>a</mi></math></root>';
 
 export const singleMiNoRoot = '<math><mi>b</mi></math>';
+
+export const mrow = `
+<root>
+  <math>
+    <mrow>
+      <mn>2</mn>
+      <mo>+</mo>
+      <mn>2</mn>
+    </mrow>
+  </math>
+</root>
+`;
+
+export const mfencedWithSeparatorAttribute = `
+<root>
+  <math>
+  <mfenced separators=';;;'>
+    <mn>3</mn>
+    <mn>2</mn>
+    <mn>1</mn>
+  </mfenced>
+  </math>
+</root>
+`;
+
+export const mfencedWithBrokenAttribute = `
+<root>
+  <math>
+  <mfenced open='{' close >
+    <mn>3</mn>
+  </mfenced>
+  </math>
+</root>
+`;

src/converters/mathml-string-to-mathml-interfaces/ElementsToMathMLInterfacesConvertor.ts

@@ -16,7 +16,7 @@ export class ElementsToMathMLInterfacesConvertor {
 
   private _convertElementAttributes(attributes: NamedNodeMap): Record<string, string> {
     return Array.from(attributes).reduce(
-      (acc, attr: Attr) => Object.assign({ [attr.nodeName]: attr.nodeValue }, acc),
+      (acc, attr: Attr) => Object.assign({ [attr.nodeName]: attr.nodeValue === attr.nodeName ? '' : attr.nodeValue }, acc),
       {},
     );
   }