fix(orm): more robust timezone adjustment for postgres

[ymc9]

Summary by CodeRabbit

• Bug Fixes

  • Improved PostgreSQL date handling: string dates are now validated before parsing, existing timezone offsets are preserved, and missing offsets are normalized so parsed dates reflect correct UTC timing. Non-date values and prior Date-handling behavior remain unchanged.

• Chores

  • No public API or exported signatures were changed.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Caution

Review failed

The pull request is closed.

Note

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CodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review.

Walkthrough

The PostgreSQL dialect's PostgresCrudDialect gained a private Zod-based isoDateSchema and updated transformOutputDate to validate ISO-like date strings; strings matching the schema are checked for an existing UTC offset and get a trailing 'Z' appended if none; non-matching strings and non-string values are unchanged.

Changes

Cohort / File(s)	Summary
PostgreSQL Date Validation packages/orm/src/client/crud/dialects/postgresql.ts	Added zod import and a private isoDateSchema member. Updated transformOutputDate to: validate string values with isoDateSchema.safeParse(value), detect existing offset (endsWith Z or ±HH:MM), append 'Z' when no offset exists before constructing Date. Preserved previous handling for Date objects and other non-string values.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Verify the isoDateSchema regex/pattern accurately matches intended ISO-like formats.
• Confirm offset detection logic (trailing Z or ±HH:MM) avoids false negatives/positives and prevents double-appending.
• Check interactions with existing Date handling paths and ensure no behavioral regressions for non-string inputs.

Possibly related PRs

• fix(orm): more robust timezone adjustment for postgres #461 — Applies the same zod isoDateSchema addition and transformOutputDate offset-append logic in the same file.
• fix(orm): correcting timezone for Date returned in nested queries #450 — Modifies transformOutputDate to ensure string dates get a UTC offset (appending Z) before Date construction.
• merge dev to main #261 — Updates PostgreSQL dialect date transformation logic with similar ISO string validation and timezone handling.

Poem

🐰 I nibble at timestamps, neat and spry,
I check for Z or +04:00 in the sky,
If none I find, I tuck a Z on tight,
Now dates sleep safe, tidy through the night. ✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title 'fix(orm): more robust timezone adjustment for postgres' directly and clearly summarizes the main change: improving timezone handling in the PostgreSQL ORM dialect.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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📜 Recent review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 5775242 and 78ecc70.

📒 Files selected for processing (1)

• packages/orm/src/client/crud/dialects/postgresql.ts (3 hunks)

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[claude]

Claude finished @ymc9's task —— View job

---

Code Review Completed ✅

I've reviewed the timezone adjustment improvements for PostgreSQL. Here's my comprehensive analysis:

Todo List

• Read and analyze the changed file
• Review code quality and best practices
• Check for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Consider test coverage needs
• Provide comprehensive feedback

---

Summary of Changes

The PR introduces more robust timezone handling for PostgreSQL date/time values by:

1. Adding Zod ISO datetime validation schema
2. Improving string date parsing logic to validate ISO format before processing
3. Adding timezone offset detection to avoid unnecessary 'Z' suffix addition

Code Quality Assessment

✅ Strengths

• Defensive Programming: The new validation using this.isoDateSchema.safeParse(value).success prevents processing invalid date strings
• Improved Logic: The hasOffset check (value.endsWith('Z') || /[+-]\d{2}:\d{2}$/.test(value)) properly detects existing timezone information
• Better Comments: Updated comment correctly describes the behavior (fixes "timestamptz" → "timestamp" typo)
• Minimal Dependencies: Leverages existing Zod dependency rather than adding new ones

⚠️ Areas for Improvement

Performance Considerations:

• Line 116: this.isoDateSchema.safeParse(value).success runs full Zod validation on every string date value. For high-throughput applications, this could be a bottleneck
• Suggestion: Consider a lightweight regex pre-check before Zod validation:

  // Quick regex check before expensive Zod validation
  const looksLikeIsoDate = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/.test(value);
  if (looksLikeIsoDate && this.isoDateSchema.safeParse(value).success) {
      // ... existing logic
  }

Error Handling:

• Line 120: When validation fails, the function returns the original string value, which could lead to inconsistent return types (Date vs string)
• Consideration: Should invalid date strings throw an error or log a warning for debugging?

Regex Security:

• Line 117: The regex /[+-]\d{2}:\d{2}$/.test(value) is safe and efficient - no ReDoS concerns

Technical Issues

❌ Potential Bug

Lines 30 & 116: The isoDateSchema is created with { local: true, offset: true }, but it's unclear if this matches the actual PostgreSQL timestamp format expectations.

• PostgreSQL timestamp (without timezone) should not have timezone info
• PostgreSQL timestamptz would have timezone info
• The current validation might be too permissive

Recommendation: Verify this validation aligns with your actual PostgreSQL column types and data format.

Security Assessment

✅ No security concerns identified

• Input validation is properly implemented
• No SQL injection vectors introduced
• Regex is safe from ReDoS attacks

Test Coverage Recommendations

Critical Test Cases Needed:

1. Invalid ISO strings: Ensure non-ISO date strings are handled gracefully

   // Test cases:
   transformOutputDate("invalid-date")
   transformOutputDate("2023-13-01T25:00:00") // Invalid date/time
   transformOutputDate("not a date at all")

2. Timezone edge cases:

   transformOutputDate("2023-01-01T12:00:00.123456") // No timezone
   transformOutputDate("2023-01-01T12:00:00.123456Z") // UTC
   transformOutputDate("2023-01-01T12:00:00.123456+05:30") // With offset
   transformOutputDate("2023-01-01T12:00:00.123456-08:00") // Negative offset

3. Performance regression tests: Measure impact of Zod validation on high-volume date processing

Overall Assessment

This is a solid improvement that makes timezone handling more robust and defensive. The changes are well-targeted and address a real issue with PostgreSQL date handling. The main concerns are around performance optimization and ensuring the validation schema matches expected data formats.

Recommendation: ✅ Approve with minor suggestions - consider the performance optimization and additional test coverage mentioned above.

[Copilot]

Pull request overview

This PR enhances timezone handling for PostgreSQL's datetime transformation by adding validation to check if string values are valid ISO 8601 datetime strings before adding a 'Z' suffix. The change aims to prevent incorrectly modifying strings that already have timezone information or are not valid datetime strings.

Key changes:

• Added Zod schema to validate ISO 8601 datetime strings before transformation
• Updated logic to only append 'Z' to datetime strings without existing timezone offset
• Improved comment documentation for timestamp handling

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[claude]

Claude finished @ymc9's task —— View job

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Code Review Completed ✅

I've reviewed the timezone adjustment improvements for PostgreSQL. Here's my comprehensive analysis:

Todo List

• Read and analyze the changed file
• Review code quality and best practices
• Check for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Consider test coverage needs
• Provide comprehensive feedback

---

Summary of Changes

The PR introduces more robust timezone handling for PostgreSQL date/time values by:

1. Adding Zod ISO datetime validation schema
2. Improving string date parsing logic to validate ISO format before processing
3. Adding timezone offset detection to avoid unnecessary 'Z' suffix addition

Code Quality Assessment

✅ Strengths

• Defensive Programming: The new validation using this.isoDateSchema.safeParse(value).success prevents processing invalid date strings
• Improved Logic: The hasOffset check (value.endsWith('Z') || /[+-]\d{2}:\d{2}$/.test(value)) properly detects existing timezone information
• Better Comments: Updated comment correctly describes the behavior (fixes "timestamptz" → "timestamp" typo)
• Minimal Dependencies: Leverages existing Zod dependency rather than adding new ones

⚠️ Areas for Improvement

Performance Considerations:

• Line 116: this.isoDateSchema.safeParse(value).success runs full Zod validation on every string date value. For high-throughput applications, this could be a bottleneck
• Suggestion: Consider a lightweight regex pre-check before Zod validation:

  // Quick regex check before expensive Zod validation
  const looksLikeIsoDate = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/.test(value);
  if (looksLikeIsoDate && this.isoDateSchema.safeParse(value).success) {
      // ... existing logic
  }

Error Handling:

• Line 120: When validation fails, the function returns the original string value, which could lead to inconsistent return types (Date vs string)
• Consideration: Should invalid date strings throw an error or log a warning for debugging?

Regex Security:

• Line 117: The regex /[+-]\d{2}:\d{2}$/.test(value) is safe and efficient - no ReDoS concerns

Technical Issues

❌ Critical Issues Found (matching Copilot's findings)

1. Line 30: z.iso.datetime() is invalid Zod syntax. Should be z.string().datetime({ local: true, offset: true })
2. Line 108: Typo "timestampt" should be "timestamp"
3. Line 113: Grammar issue "without timezone" should be "without a timezone"

❌ Potential Bug

Lines 30 & 116: The isoDateSchema is created with { local: true, offset: true }, but it's unclear if this matches the actual PostgreSQL timestamp format expectations.

• PostgreSQL timestamp (without timezone) should not have timezone info
• PostgreSQL timestamptz would have timezone info
• The current validation might be too permissive

Recommendation: Verify this validation aligns with your actual PostgreSQL column types and data format.

Security Assessment

✅ No security concerns identified

• Input validation is properly implemented
• No SQL injection vectors introduced
• Regex is safe from ReDoS attacks

Test Coverage Recommendations

Critical Test Cases Needed:

1. Invalid ISO strings: Ensure non-ISO date strings are handled gracefully

   // Test cases:
   transformOutputDate("invalid-date")
   transformOutputDate("2023-13-01T25:00:00") // Invalid date/time
   transformOutputDate("not a date at all")

2. Timezone edge cases:

   transformOutputDate("2023-01-01T12:00:00.123456") // No timezone
   transformOutputDate("2023-01-01T12:00:00.123456Z") // UTC
   transformOutputDate("2023-01-01T12:00:00.123456+05:30") // With offset
   transformOutputDate("2023-01-01T12:00:00.123456-08:00") // Negative offset

3. Performance regression tests: Measure impact of Zod validation on high-volume date processing

Overall Assessment

This is a solid improvement that makes timezone handling more robust and defensive. The changes are well-targeted and address a real issue with PostgreSQL date handling. The main concerns are around performance optimization and ensuring the validation schema matches expected data formats.

Recommendation: ✅ Approve with minor suggestions - consider the performance optimization and additional test coverage mentioned above.

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