add singleLineInputFix test

Author: TaduJR

src/__tests__/singleLineInputFix.test.tsx

@@ -0,0 +1,117 @@
+import {expect} from '@jest/globals';
+import {parseRangesToHTMLNodes} from '../web/utils/parserUtils';
+import parseExpensiMark from '../parseExpensiMark';
+
+/**
+ * Focused tests for the single-line input fix
+ * These tests validate the specific fix for unwanted space insertion
+ */
+
+describe('Single-line input fix validation', () => {
+  describe('parseRangesToHTMLNodes with isMultiline parameter', () => {
+    it('should not generate BR elements for single-line text (isMultiline=false)', () => {
+      const text = 'simple text';
+      const ranges = parseExpensiMark(text);
+
+      const result = parseRangesToHTMLNodes(text, ranges, false, {}, true);
+
+      // Should not contain BR elements for single-line input
+      expect(result.dom.innerHTML).not.toContain('<span data-type="br">');
+      expect(result.dom.innerHTML).not.toContain('<br>');
+    });
+
+    it('should generate proper structure for multiline text (isMultiline=true)', () => {
+      const text = 'line 1\nline 2';
+      const ranges = parseExpensiMark(text);
+
+      const result = parseRangesToHTMLNodes(text, ranges, true, {}, true);
+
+      // Should contain proper paragraph structure for multiline
+      expect(result.dom.innerHTML).toContain('<p data-type="line"');
+      // Note: The library may not always use BR elements depending on the implementation
+      // The key is that it handles multiline properly
+      expect(result.dom.innerHTML.split('<p data-type="line"').length - 1).toBeGreaterThan(1);
+    });
+
+    it('should not generate BR elements for single-line markdown (isMultiline=false)', () => {
+      const text = 'hello *world* test';
+      const ranges = parseExpensiMark(text);
+
+      const result = parseRangesToHTMLNodes(text, ranges, false, {}, true);
+
+      // Should not contain BR elements but should have markdown formatting
+      expect(result.dom.innerHTML).not.toContain('<span data-type="br">');
+      expect(result.dom.innerHTML).not.toContain('<br>');
+      expect(result.dom.innerHTML).toContain('data-type="bold"');
+    });
+
+    it('should handle empty single-line input without BR elements (isMultiline=false)', () => {
+      const text = '';
+      const ranges = parseExpensiMark(text);
+
+      const result = parseRangesToHTMLNodes(text, ranges, false, {}, true);
+
+      // For empty input, should either be empty or have minimal structure without BR
+      const html = result.dom.innerHTML;
+      if (html !== '') {
+        // If there's structure, it shouldn't have BR elements for single-line
+        expect(html).not.toContain('<span data-type="br">');
+      }
+    });
+
+    it('should preserve existing multiline behavior when isMultiline=true', () => {
+      const singleLineText = 'test text';
+      const ranges = parseExpensiMark(singleLineText);
+
+      // Compare single-line vs multiline behavior
+      const singleLineResult = parseRangesToHTMLNodes(singleLineText, ranges, false, {}, true);
+      const multilineResult = parseRangesToHTMLNodes(singleLineText, ranges, true, {}, true);
+
+      // Single-line should be more compact than multiline
+      expect(singleLineResult.dom.innerHTML.length).toBeLessThanOrEqual(multilineResult.dom.innerHTML.length);
+
+      // Single-line should not have BR elements
+      expect(singleLineResult.dom.innerHTML).not.toContain('<span data-type="br">');
+    });
+  });
+
+  describe('Integration test for the original bug scenario', () => {
+    it('should demonstrate the fix for typing after selecting all text', () => {
+      // This test validates the core fix: when user types "t" after selecting all,
+      // the generated DOM should not contain elements that would cause space insertion
+
+      const userTypedText = 't';
+      const ranges = parseExpensiMark(userTypedText);
+
+      // Generate DOM with single-line setting (the fix)
+      const result = parseRangesToHTMLNodes(userTypedText, ranges, false, {}, true);
+
+      // Critical assertions for the fix:
+      // 1. Should not contain BR elements that add newlines
+      expect(result.dom.innerHTML).not.toContain('<span data-type="br">');
+      expect(result.dom.innerHTML).not.toContain('<br>');
+
+      // 2. Should contain the text properly structured
+      expect(result.dom.innerHTML).toContain('t');
+
+      // 3. The DOM should be as minimal as possible for single character
+      expect(result.dom.innerHTML.length).toBeLessThan(200); // Reasonable upper bound
+    });
+
+    it('should work correctly with markdown in single-line context', () => {
+      // Test that our fix doesn't break markdown functionality
+      const markdownText = '*bold* normal `code`';
+      const ranges = parseExpensiMark(markdownText);
+
+      const result = parseRangesToHTMLNodes(markdownText, ranges, false, {}, true);
+
+      // Should have proper markdown elements
+      expect(result.dom.innerHTML).toContain('data-type="bold"');
+      expect(result.dom.innerHTML).toContain('data-type="code"');
+
+      // But no BR elements
+      expect(result.dom.innerHTML).not.toContain('<span data-type="br">');
+      expect(result.dom.innerHTML).not.toContain('<br>');
+    });
+  });
+});