fix: unwanted space insertion in single line markdown text input when replacing selected text

[TaduJR]

Fixes #716

Details

This PR fixes a bug where MarkdownTextInput with multiline={false} incorrectly inserts spaces when users select all text and type a replacement character. The issue was caused by the library treating all text input as potentially multiline during processing, regardless of the multiline prop value.

Root Cause:
The library was adding BR elements (containing \n characters) and newlines during both DOM generation and text extraction phases, even for single-line inputs. These newlines then got converted to spaces during text normalization.

Changes Made:

1. Fixed BR element addition in addTextToElement() function (parserUtils.ts)

• Made BR element addition conditional on isMultiline parameter
• Prevents unwanted newline characters in single-line inputs

2. Updated addTextToElement() function calls (parserUtils.ts)

• Pass isMultiline parameter to all function calls within parseRangesToHTMLNodes()
• Ensures multiline setting is respected throughout DOM generation

3. Enhanced parseInnerHTMLToText() function (inputUtils.ts)

• Added isMultiline = true parameter to maintain backward compatibility
• Made newline addition conditional in both top-level component processing and BR element parsing
• Prevents unwanted newlines during text extraction for single-line inputs

4. Connected multiline prop in MarkdownTextInput.web.tsx

• Pass multiline prop to parseInnerHTMLToText() function
• Ensures the component's multiline setting flows through the entire processing chain

Impact:

• ✅ Single-line inputs no longer get unwanted spaces
• ✅ Multiline inputs continue to work correctly
• ✅ Markdown highlighting preserved for both input types
• ✅ No breaking changes to existing API
• ✅ Backward compatible (all new parameters have defaults)

Related Issues

GH_LINK

Manual Tests

Test Scenarios Covered:

1. Single-line text replacement:

   • Create MarkdownTextInput with multiline={false}
   • Enter text, select all, type replacement
   • Verify no extra spaces are added

2. Multiline preservation:

   • Create MarkdownTextInput with multiline={true}
   • Test that line breaks continue to work correctly

3. Markdown highlighting:

   • Test single-line inputs with various markdown syntax
   • Verify highlighting works without adding unwanted spaces

4. Edge cases:

   • Empty inputs, inputs with only spaces, special characters
   • Mixed markdown content (bold, italic, etc.)

5. Regression testing:

   • Verified existing multiline functionality remains unchanged
   • Confirmed no impact on markdown parsing or rendering

Manual Testing Steps:

1. Open WebExample or any app using the library
2. Create a search input with multiline={false} and type="markdown"
3. Enter text like "type:expense group-by:reports"
4. Select all text (Ctrl+A)
5. Type a single character like "t"
6. Before fix: Shows "t " (with unwanted space)
7. After fix: Shows "t" (clean, no extra space)

[os-botify]

🚀 Published to npm in 0.1.299 🎉