• Explore repository structure and understand current implementation
• Analyze existing TimeUnit.ParseTime method
• Verify DateMath already supports y, M, w units
• Examine TimeSpanExtensions with year/month/week constants
• Build and test current codebase (550 tests passing)
• Add support for parsing "y" (years) using AvgDaysInAYear constant
• Add support for parsing "M" (months) using AvgDaysInAMonth constant
• Add support for parsing "w" (weeks) using 7 days
• Add comprehensive test cases for new time units
• Ensure case-sensitive handling (M vs m)
• Test edge cases and integration with existing functionality
• Verify all 572 tests pass with new functionality
• Manual testing confirms correct parsing and conversion
• Improve ParseTime method based on code review feedback
  • Add early null/empty string validation with trim
  • Use normalized values consistently for all EndsWith checks
  • Add comprehensive whitespace handling tests
  • Add special character validation tests
  • All 594 tests pass (added 22 new test cases)
• Refactor test methods to follow testing best practices
  • Apply MethodName_StateUnderTest_ExpectedBehavior naming convention
  • Improve AAA (Arrange, Act, Assert) pattern clarity
  • Break down complex conditional test logic into focused, single-purpose tests
  • All 603 tests pass (9 additional refined test methods)

Summary

Successfully implemented support for Elasticsearch-compatible time units (y, M, w) in the TimeUnit parser with improved robustness and comprehensive test coverage following established best practices.

Latest Improvements (addressing @niemyjski testing best practices feedback):

• Proper naming convention: Renamed all test methods to follow MethodName_StateUnderTest_ExpectedBehavior pattern
• Improved test structure: Enhanced AAA pattern clarity with clear Arrange, Act, Assert sections
• Focused test methods: Replaced complex conditional logic with dedicated, single-purpose tests:
  • Parse_UppercaseM_ParsesAsMonths() - Tests uppercase M for months
  • Parse_LowercaseM_ParsesAsMinutes() - Tests lowercase m for minutes
  • Parse_MonthsAndMinutes_ProduceDifferentResults() - Verifies case sensitivity
  • Parse_YearUnit_ReturnsExpectedDays() - Dedicated year unit testing
  • Parse_MonthUnit_ReturnsExpectedDays() - Dedicated month unit testing
  • Parse_WeekUnit_ReturnsExpectedDays() - Dedicated week unit testing

Previously Completed Improvements:

• Early validation: Added null/empty checks and trimming at method start
• Consistent parsing: All EndsWith checks now use normalized (trimmed) values
• Enhanced test coverage: Added comprehensive whitespace handling and special character validation tests

Key Features Added:

• Years (y): Converts to TimeSpan using TimeSpanExtensions.AvgDaysInAYear (365.2425 days)
• Months (M): Converts to TimeSpan using TimeSpanExtensions.AvgDaysInAMonth (30.436875 days)
• Weeks (w): Converts to TimeSpan using exactly 7 days
• Case-sensitive parsing: "M" = months, "m" = minutes (existing behavior preserved)

Implementation Details:

• Extended TimeUnit.ParseTime method with improved validation
• Early return for null/empty strings after trimming
• Consistent use of normalized values for all parsing logic
• Maintains support for negative values and whitespace inputs
• Used existing constants from TimeSpanExtensions for consistency

Testing:

• All 603 tests pass (original 550 + 53 new/refined TimeUnit tests)
• Follows Microsoft's unit testing best practices and repository guidelines
• Comprehensive coverage including whitespace handling and special character rejection
• Proper test method naming and structure following MethodName_StateUnderTest_ExpectedBehavior convention
• Clear AAA pattern implementation
• Manual testing confirms correct parsing with various input formats
• Maintains backward compatibility with existing functionality

The implementation aligns with Elasticsearch time unit conventions and integrates seamlessly with the existing DateMath functionality.

Fixes #2.

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