[PM-25423] Add BidiTextManager for handling bidirectional text

[SaintPatrck]

🎟️ Tracking

PM-25423

📔 Objective

This commit introduces BidiTextManager to manage and ensure correct display of text containing both LTR and RTL characters. It includes:

• BidiTextManager interface with a unicodeWrap method.
• BidiTextManagerImpl as the default implementation, using androidx.core.text.BidiFormatter.
• LocalBidiTextManager CompositionLocal for providing the manager in Compose UI.

📸 Screenshots

Before

After

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

Checkmarx One – Scan Summary & Details – cd892bb2-5c69-4b29-9d36-57ee8ae43bac

Great job! No new security vulnerabilities introduced in this pull request

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.78%. Comparing base (562b48d) to head (eff8906).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5825      +/-   ##
==========================================
+ Coverage   84.74%   84.78%   +0.03%     
==========================================
  Files         737      720      -17     
  Lines       55439    55051     -388     
  Branches     7655     7653       -2     
==========================================
- Hits        46983    46675     -308     
+ Misses       5775     5695      -80     
  Partials     2681     2681              

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[SaintPatrck]

@codokie Can you confirm if the Verification Codes are being handled correctly in the screenshots? If the code is 123 456, should it appear as 456 123, or 123 456 when the app language is RTL?

[codokie]

If the code is 123 456, should it appear as 456 123, or 123 456 when the app language is RTL?

It should appear as 123 456. Even though letters are written from right-to-left, Western Arabic numerals are interpreted from left-to-right.

I have seen a very few apps which do not take this into consideration and thus expect 456 123 or 654 321 as input.

Most localized services consider 123456 as the correct input because they don’t even use a space to divide the verification code. Preferring 456 123 would cause much confusion.

By the way, I’m not sure if #5012 handled verification codes correctly because I had used a dummy account w/o Premium for testing. So it’s good thing that you’ve brought this up.

[codokie]

While trying to test this change on my end, I noticed that it did not have any effect unless BitwardenTextField and BitwardenPasswordField were modified to use the new BidiTextManager (it was also necessary initialize it in LocalManagerProvider).

Having done that, after a brief testing I can say that your minimalistic method fixes most of the issues described in #4753, with the added benefit that it does not cause alignment issues like in #5012.

However, I’ve noticed 3 issues that make me doubt if unicodeWrap should be the preferred approach:

1. Saved password with the value of 1234* appears as *1234, which is wrong.
2. The caret position is not updated correctly. This makes editing text fields uncomfortable.
3. After pressing the backspace key in an empty input field, the first character is shifted upon entering the second character. Very unexpected.

Video demonstrating points 1 & 2 (click to expand)

1.and.2.webm

Notice that the caret is incorrectly aligned to the left.

The input should have appeared as test12@

Video demonstrating point no. 3 (click to expand)

3.webm

This happened while trying to write user

[claude]

Claude finished @SaintPatrck's task —— View job

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Code Review: BidiTextManager for Bidirectional Text Handling

I've completed a comprehensive review of this PR. While the implementation demonstrates good architectural practices, there are critical issues identified by @codokie that need to be addressed before merging.

---

Summary of Changes

This PR introduces BidiTextManager to handle bidirectional text display for RTL languages (Arabic, Hebrew). The implementation:

• Adds interface BidiTextManager with methods for wrapping text with Unicode directionality markers
• Provides BidiTextManagerImpl using androidx.core.text.BidiFormatter
• Integrates via LocalBidiTextManager CompositionLocal
• Applies to vault items: login credentials, card details, identity fields, and verification codes
• 15 files changed with +277/-18 lines

---

Critical Issues ⚠️

1. BLOCKER: TextField Integration Problems

@codokie identified three critical issues when the BidiTextManager is applied to editable text fields (though this PR currently only applies it to read-only display fields):

Issue Details from Testing

1. Incorrect character ordering: Password 1234* displays as *1234 (wrong order)
2. Broken caret positioning: Cursor position doesn't update correctly during editing
3. Character shift on backspace: After backspace in empty field, first character shifts when entering second character

These issues suggest that unicodeWrap() is not suitable for editable text fields - only for read-only display text.

Current Status: This PR only applies BidiTextManager to read-only fields, so these issues don't immediately affect this implementation. However:

• The interface design suggests it might be used for editable fields in the future
• Documentation should explicitly warn against using this on editable TextField components
• Consider adding a comment in BidiTextManager.kt:26 explaining this limitation

Recommendation: Add KDoc warnings and consider whether the interface should be redesigned to prevent misuse on editable fields.

---

Architecture & Design Issues

2. Missing Comprehensive Tests

Severity: High

BidiTextManagerTest.kt only validates empty string handling. Missing tests for:

• unicodeWrap() behavior with mixed LTR/RTL text
• forceLtr() and forceRtl() output verification
• formatVerificationCode() chunking and directionality
• formatPhoneNumber() and formatCardNumber() directionality enforcement

Location: ui/src/test/kotlin/com/bitwarden/ui/platform/manager/BidiTextManagerTest.kt:15-31

// Current test coverage is minimal:
@Test
fun `formatVerificationCode handles empty string`() {
    val result = manager.formatVerificationCode("")
    assertEquals("", result)
}

Recommendation: Add comprehensive unit tests or document why instrumentation tests are preferred for BidiFormatter behavior.

---

3. Inconsistent Application of BidiTextManager

Severity: Medium

The PR applies different methods inconsistently across similar data types:

Field Type	Method Used	Location
Password	unicodeWrap()	VaultItemLoginContent.kt:402
URI	unicodeWrap()	VaultItemLoginContent.kt:516
Card Number	formatCardNumber() (forceLtr)	VaultItemCardContent.kt:99
Security Code	forceLtr()	VaultItemCardContent.kt:179
SSN	forceLtr()	VaultItemIdentityContent.kt:143
Email	unicodeWrap()	VaultItemIdentityContent.kt:209
Phone	formatPhoneNumber() (forceLtr)	VaultItemIdentityContent.kt:231
Passport Number	unicodeWrap()	VaultItemIdentityContent.kt:165
License Number	unicodeWrap()	VaultItemIdentityContent.kt:187

Questions:

1. Why does SSN use forceLtr() while passport/license numbers use unicodeWrap()? All are typically numeric/alphanumeric identifiers.
2. Should email addresses always use unicodeWrap() or should they be forced LTR like phone numbers?
3. Is there a documented decision matrix for which method to use?

Recommendation: Document the decision criteria for choosing between unicodeWrap(), forceLtr(), and forceRtl() in the interface KDoc or create a separate doc explaining the usage patterns.

---

4. Verification Code Handling Confirmed Correct ✓

Severity: N/A (Positive Finding)

Per @codokie's confirmation, verification codes correctly display as 123 456 (not 456 123) in RTL mode. Western Arabic numerals are interpreted left-to-right even in RTL contexts. The implementation at VaultItemLoginContent.kt:458-461 and VerificationCodeItem.kt:112 is correct.

---

Code Quality Issues

5. @OmitFromCoverage Overuse

Severity: Low

Multiple files are marked @OmitFromCoverage without clear justification:

• BidiTextManagerImpl.kt:11 - Implementation could be unit tested
• LocalBidiTextManagerProvider.kt:1 - CompositionLocal provider
• BidiTextManagerBuilder.kt:1 - DSL builder could be tested

Recommendation: Only use @OmitFromCoverage for truly untestable code (e.g., Android framework dependencies). Consider testing BidiTextManagerImpl with instrumented tests or mock BidiFormatter.

---

6. Card Number Formatting Removed

Severity: Low (Intentional Change)

Commit 12625daab removed card number formatting logic from formatCardNumber(). The method now only applies forceLtr() without grouping digits.

Before:

override fun formatCardNumber(number: String): String {
    val digits = number.filter { it.isDigit() }
    val chunks = digits.chunked(4)
    return forceLtr(chunks.joinToString(" "))
}

After (current):

override fun formatCardNumber(number: String): String {
    if (number.isEmpty()) return ""
    return forceLtr(number)
}

Question: Was this intentional? Does the app handle card number formatting elsewhere?

Recommendation: Confirm this change is intentional and update KDoc if the method no longer provides formatting.

---

Good Practices Observed 👍

• Clean architecture: Manager pattern in :ui module aligns with project structure
• Dependency injection: Proper Hilt integration via DSL builder
• CompositionLocal usage: Appropriate for cross-cutting UI concerns
• Interface segregation: Clean interface with focused methods
• Commit hygiene: 21 well-structured commits with clear messages
• Security scan passed: No new vulnerabilities introduced
• Test coverage maintained: 84.78% overall coverage (per Codecov)

---

Action Items for Author

Must Address (Blocking)

• Add documentation to BidiTextManager interface explaining it should NOT be used with editable TextField components (see Critical Issue Android Accessibility Service #1)
• Add comprehensive unit tests for all BidiTextManager methods (Issue Site Search #2)
• Document decision criteria for when to use unicodeWrap() vs forceLtr() vs forceRtl() (Issue Fully Implement Change Password Flow for Extension #3)

Should Address (Non-blocking but Important)

• Clarify inconsistent method choices across similar field types (Issue Fully Implement Change Password Flow for Extension #3)
• Confirm card number formatting removal was intentional (Issue F-Droid Support #6)
• Review @OmitFromCoverage usage and add tests where feasible (Issue Subdomain Only Option for Sites #5)

Nice to Have

• Add instrumented tests showing actual RTL behavior on device/emulator
• Consider adding usage examples to method KDocs
• Document the verification code design decision (123 456 vs 456 123) in code comments

---

References

• Issue RTL text direction #4753: Original bidirectional text issue
• PR [PM-20026] RTL text direction #5012: Previous attempt (had alignment issues)
• docs/ARCHITECTURE.md - Manager pattern guidelines
• docs/STYLE_AND_BEST_PRACTICES.md - Code style requirements

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[SaintPatrck]

Pivoting to a different approach.