tc39/test262
Nov 2025 – Mar 2026
2 Months active
Languages Used
JavaScript
Technical Skills
API developmentJavaScriptTemporal APIcalendar handlingcalendar systemsdate manipulation
Jesse Alama
PROFILE
Jesse Alama
Jesse contributed to the tc39/test262 repository by developing and expanding comprehensive test suites for JavaScript’s Temporal API, focusing on cross-calendar correctness, historical date support, and internationalization. He designed and implemented tests that validated date arithmetic, era boundaries, and formatting across diverse calendar systems, including Islamic, Japanese, and Chinese calendars. Using JavaScript and advanced calendar algorithms, Jesse improved error handling by ensuring robust input validation and precise exception ordering. His work refined test coverage for edge cases, time zone transitions, and non-Latin numerals, enhancing standards conformance and reliability for engines implementing Temporal and Intl APIs across global calendar scenarios.
Overall Statistics
Feature vs Bugs
83%Features
Repository Contributions
23Total
Bugs
1
Commits
23
Features
5
Lines of code
9,067
Activity Months2
Your Network
159 peopleSame Organization
@igalia.com92
Work History
March 2026
10 Commits • 2 Features
Mar 1, 2026March 2026 monthly summary for tc39/test262: expanded Temporal API test coverage focusing on historical calendars, internationalization, time zones, and error handling; added tests, refined/removed invalid/test fixtures; improved reliability and standards conformance with explicit edge-case testing across calendar systems and date ranges.
10 Commits • 2 Features
Mar 1, 2026March 2026 monthly summary for tc39/test262: expanded Temporal API test coverage focusing on historical calendars, internationalization, time zones, and error handling; added tests, refined/removed invalid/test fixtures; improved reliability and standards conformance with explicit edge-case testing across calendar systems and date ranges.
March 2026
November 2025
13 Commits • 3 Features
Nov 1, 2025Month: 2025-11 | Repository: tc39/test262 Key features delivered and major tests added across multiple calendars to strengthen cross-calendar correctness and formatting behavior: - Cross-calendar and cross-era date arithmetic and difference tests: Validates date addition/subtraction and difference computations across Islamic, Ethiopian, Gregorian, Japanese, and ROC calendars, with a focus on era boundaries and cross-calendar consistency. - Intl.DateTimeFormat calendar and era formatting tests: Covers calendar resolution, leap months in lunisolar calendars, and era formatting across supported calendars. - Temporal.PlainMonthDay.from calendar month code validation: Validates month codes for non-ISO calendars (e.g., Buddhist, Chinese, Coptic) to ensure invalid codes are rejected and valid codes accepted. Major bugs fixed: - CalendarResolveFields robustness and error handling: Ensures missing required fields throw TypeError before ValueError, improving error handling in date/time operations. Overall impact and accomplishments: - Strengthened cross-calendar correctness and consistency across multiple calendar systems, improving reliability of Intl APIs and date/time computations in test262. - Improved error handling and input validation, reducing ambiguity when required fields are missing and preventing misclassification of errors. - Strengthened collaboration and test coverage for CLDR-driven calendar configurations, paving the way for smoother updates to calendar data in CLDR revisions. Technologies/skills demonstrated: - JavaScript Intl API testing, calendar-aware test design, CLDR-based calendar configurations, test-driven development, and cross-team collaboration (co-authored commits). Top 3-5 achievements: - Delivered cross-calendar era boundary tests for Islamic, Ethiopian, Gregorian, Japanese, and ROC calendars. - Validated DateTimeFormat.calendar resolution and era formatting across multiple calendars. - Added non-ISO calendar month code validation for Buddhist, Chinese, Coptic calendars. - Strengthened error handling with CalendarResolveFields to enforce TypeError for missing fields before ValueError.
November 2025
13 Commits • 3 Features
Nov 1, 2025Month: 2025-11 | Repository: tc39/test262 Key features delivered and major tests added across multiple calendars to strengthen cross-calendar correctness and formatting behavior: - Cross-calendar and cross-era date arithmetic and difference tests: Validates date addition/subtraction and difference computations across Islamic, Ethiopian, Gregorian, Japanese, and ROC calendars, with a focus on era boundaries and cross-calendar consistency. - Intl.DateTimeFormat calendar and era formatting tests: Covers calendar resolution, leap months in lunisolar calendars, and era formatting across supported calendars. - Temporal.PlainMonthDay.from calendar month code validation: Validates month codes for non-ISO calendars (e.g., Buddhist, Chinese, Coptic) to ensure invalid codes are rejected and valid codes accepted. Major bugs fixed: - CalendarResolveFields robustness and error handling: Ensures missing required fields throw TypeError before ValueError, improving error handling in date/time operations. Overall impact and accomplishments: - Strengthened cross-calendar correctness and consistency across multiple calendar systems, improving reliability of Intl APIs and date/time computations in test262. - Improved error handling and input validation, reducing ambiguity when required fields are missing and preventing misclassification of errors. - Strengthened collaboration and test coverage for CLDR-driven calendar configurations, paving the way for smoother updates to calendar data in CLDR revisions. Technologies/skills demonstrated: - JavaScript Intl API testing, calendar-aware test design, CLDR-based calendar configurations, test-driven development, and cross-team collaboration (co-authored commits). Top 3-5 achievements: - Delivered cross-calendar era boundary tests for Islamic, Ethiopian, Gregorian, Japanese, and ROC calendars. - Validated DateTimeFormat.calendar resolution and era formatting across multiple calendars. - Added non-ISO calendar month code validation for Buddhist, Chinese, Coptic calendars. - Strengthened error handling with CalendarResolveFields to enforce TypeError for missing fields before ValueError.
Activity
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Quality Metrics
Correctness99.0%
Maintainability98.2%
Architecture98.2%
Performance98.2%
AI Usage20.0%
Skills & Technologies
Programming Languages
JavaScript
Technical Skills
API developmentJavaScriptTemporal APIcalendar algorithmscalendar handlingcalendar systemsdate manipulationinternationalizationtemporal APItesting
Repositories Contributed To
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