fix: auto-insert space before @mentions when needed #8064

roomote · 2025-09-17T08:57:44Z

Summary

This PR fixes issue #8063 where @mentions would not parse correctly when typed directly after text without a space. The issue was introduced in PR #7876 which restricted @mention parsing to only work at line-start or after whitespace to prevent accidental parsing in pasted logs.

Problem

When users:

Type @ directly after text without a space
Drag and drop files after existing text

The @mentions would not be parsed correctly because the regex requires whitespace before the @ symbol.

Solution

While keeping the regex restriction from PR #7876 (which correctly prevents parsing in pasted logs), this PR modifies the UI behavior to automatically insert a space before @ when needed:

Drag/Drop: When dragging files into the chat, check if a space is needed before the @ mention
Mention Insertion: When inserting mentions via the context menu, auto-insert space if the text before doesn't end with space or newline
Consistent Behavior: The existing insertTextIntoTextarea handler already had this logic

Changes

Modified ChatTextArea.tsx to check and add space before @ when dragging/dropping files
Updated insertMention function in context-mentions.ts to auto-insert space when needed
Added comprehensive tests for the new behavior

Testing

✅ All existing tests pass
✅ Added new tests specifically for auto-space insertion
✅ Verified backward compatibility - regex restriction from fix: restrict @-mention parsing to line-start or whitespace boundaries #7876 is maintained
✅ Linting and type checks pass

Screenshots

Before: Users had to manually add space before @ for mentions to work
After: Space is automatically inserted when needed, making the UX seamless

Fixes #8063

Important

Fixes issue #8063 by auto-inserting space before @mentions when needed, ensuring correct parsing without altering regex restrictions.

Behavior:
- Automatically inserts space before @mentions when needed in ChatTextArea.tsx and context-mentions.ts.
- Maintains regex restriction from PR fix: restrict @-mention parsing to line-start or whitespace boundaries #7876 to prevent parsing in pasted logs.
Functions:
- Updates insertMention in context-mentions.ts to handle space insertion logic.
- Modifies ChatTextArea.tsx to check and add space before @ during drag/drop and mention insertion.
Testing:
- Adds tests in context-mentions.spec.ts for auto-space insertion behavior.
- Ensures all existing tests pass and verifies backward compatibility.
Misc:
- Fixes issue [BUG] @ parsing not work when a char before @ #8063.

^{This description was created by}^{for 7ca6046. You can customize this summary. It will automatically update as commits are pushed.}

- Auto-insert space before @ when dragging/dropping files after text - Auto-insert space before @ when using mention insertion after text - Maintains regex restriction from PR #7876 to prevent parsing in pasted logs - Added comprehensive tests for the new behavior Fixes #8063

roomote

Reviewing my own code is like debugging in a mirror - everything looks backwards and I still missed the obvious bugs.

roomote · 2025-09-17T09:03:07Z

webview-ui/src/utils/context-mentions.ts

 	let newValue: string
 	let mentionIndex: number

 	if (lastAtIndex !== -1) {


Critical issue: This logic replaces everything after the FIRST @ found in the text, which causes data loss when multiple mentions exist.

For example, if the text is "Check @/file1.txt and @" and we're inserting a new mention at the second @, this will replace from the first @ instead.

Consider finding the @ that's actually at or near the cursor position instead of using lastIndexOf on the entire beforeCursor text. You might want to look for the @ closest to the cursor position that doesn't already have a complete mention after it.

roomote · 2025-09-17T09:03:07Z

webview-ui/src/utils/__tests__/context-mentions.spec.ts

+			// The function finds the @ at position 6 and replaces from there
+			// This is not the desired behavior for this case
+			// We should insert a new mention after "and"
+			expect(result.newValue).toBe("Check @/file2.txt ")


This test actually demonstrates the bug - it expects the first mention to be replaced when adding a second mention, which is incorrect behavior. The expected result should be "Check @/file1.txt and @/file2.txt " with the new mention inserted after "and", not replacing the first mention.

Is this the intended behavior? It seems like it would cause users to lose their first mention when trying to add a second one.

roomote · 2025-09-17T09:03:08Z

webview-ui/src/components/chat/ChatTextArea.tsx

 						let totalLength = 0

+						// Check if we need to add a space before the first mention
+						const textBefore = inputValue.slice(0, cursorPosition)


This space-checking logic is duplicated in the insertMention function. Since insertMention already handles adding space before @mentions, do we need this logic here as well?

Consider whether both places need this or if it should be centralized in one location to avoid potential inconsistencies.

roomote · 2025-09-17T09:03:08Z

webview-ui/src/utils/__tests__/context-mentions.spec.ts

+		// This is a side effect of the regex pattern, but not the intended use case
+		// The removeMention function is meant to be called when backspace is pressed
+		// right after a complete mention
+		expect(result.newText).toBe("Check th/to/file.txt here")


This test shows that calling removeMention from the middle of a mention produces unexpected results (removes partial text). While documented as "not the intended use case", could this lead to confusing behavior if triggered accidentally?

Might be worth adding a guard to check if we're actually at the end of a mention before attempting removal.

roomote · 2025-09-17T09:03:08Z

webview-ui/src/utils/context-mentions.ts

-		newValue = beforeCursor + "@" + processedValue + " " + afterCursor
-		mentionIndex = position
+		// Check if we need to add a space before the mention
+		const needsSpaceBefore = beforeCursor.length > 0 && !beforeCursor.endsWith(" ") && !beforeCursor.endsWith("\n")


Minor suggestion: The space-checking logic (checking for trailing space or newline) is repeated here and at line 63. Consider extracting this into a small utility function like needsSpaceBeforeMention(text: string): boolean to reduce duplication and make the intent clearer.

NaccOll · 2025-09-18T09:27:14Z

It has been tested and works as expected

daniel-lxs

LGTM, thank you @NaccOll for opening the issue!

roomote · 2025-11-06T21:43:31Z

Oroocle Follow along on Roo Cloud

Status: Posted 2 inline comments focusing on safer active-mention replacement and consistent space insertion before @mentions. Awaiting author feedback.

Guard replacement to the active @ segment only in insertMention() so earlier mentions aren’t overwritten when the caret is elsewhere
Align space-before-mention behavior across insertion paths, including newline handling in ChatTextArea.tsx and drag/drop; consider extracting a small helper like needsSpaceBeforeMention(text)

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}

roomote · 2025-11-06T21:52:01Z

webview-ui/src/utils/context-mentions.ts

 	let newValue: string
 	let mentionIndex: number

 	if (lastAtIndex !== -1) {


Active mention detection: this replaces starting at the last "@" before the cursor even if the caret is no longer inside that mention token. If the user already typed a complete mention earlier and the cursor is elsewhere, selecting a new item can overwrite the earlier mention. Replace only when there is no whitespace between the last "@" and the cursor; otherwise insert a new mention.

Suggested change

if (lastAtIndex !== -1) {

const isActiveMention = lastAtIndex !== -1 && !/\s/.test(beforeCursor.slice(lastAtIndex + 1))

if (isActiveMention) {

_{Fix it with Roo Code or mention @roomote and request a fix.}

roomote bot requested review from cte, jr and mrubens as code owners September 17, 2025 08:57

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dosubot bot added size:XL This PR changes 500-999 lines, ignoring generated files. bug Something isn't working labels Sep 17, 2025

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roomote bot mentioned this pull request Sep 17, 2025

[BUG] @ parsing not work when a char before @ #8063

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test: fix context-mentions tests after auto-space feature

dbf6a7d

dosubot bot added size:L This PR changes 100-499 lines, ignoring generated files. and removed size:XL This PR changes 500-999 lines, ignoring generated files. labels Sep 19, 2025

test: update context-mentions tests for auto-space feature

7ca6046

dosubot bot added size:M This PR changes 30-99 lines, ignoring generated files. and removed size:L This PR changes 100-499 lines, ignoring generated files. labels Sep 19, 2025

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fix: auto-insert space before @mentions when needed #8064

fix: auto-insert space before @mentions when needed #8064

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	if (lastAtIndex !== -1) {
	const isActiveMention = lastAtIndex !== -1 && !/\s/.test(beforeCursor.slice(lastAtIndex + 1))
	if (isActiveMention) {

fix: auto-insert space before @mentions when needed #8064

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roomote bot commented Sep 17, 2025 •

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