Support Windows Timezones

[muness]

#192 - Add a task to down Official Unicode CLDR Mappings. Use them to pre-process VEVENTS if ical-node throws a "TypeError: N.startsWith is not a function" error

Summary by CodeRabbit

• New Features

  • Improved ICS calendar parsing with automatic mapping of Microsoft/Windows timezones to IANA, enhancing compatibility with Office 365 invites and reducing timezone-related failures.
  • More robust handling of recurrence and RECURRENCE-ID events with Microsoft timezones.

• Bug Fixes

  • Resolved parsing errors caused by malformed or unrecognized timezone identifiers, preventing crashes and retries gracefully.

• Tests

  • Added extensive test coverage for Microsoft timezone scenarios, recurrence overrides, and mapping coverage.

• Chores

  • Added an npm script to update timezone mappings automatically.

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

Adds a timezone update script and npm entry, introduces ICS preprocessing to map Windows to IANA timezones with retry-on-error parsing, generates mapping artifacts, and adds extensive tests validating Microsoft timezone handling and mapping coverage.

Changes

Cohort / File(s)	Summary
Scripts & npm package.json	Adds npm script update-timezones mapped to node scripts/update-timezones.js.
Timezone mapping generator scripts/update-timezones.js, src/generated/windowsTimezones.ts, src/generated/windows-to-iana.json, src/generated/windows-to-iana.yaml	New script fetches CLDR WindowsZones, parses primary Windows→IANA mappings, and writes generated TS module, JSON metadata, and YAML mapping files with basic error handling and logging.
ICS preprocessing for Windows TZIDs src/icalUtils.ts	Adds preprocessing to rewrite Windows/Microsoft TZIDs to IANA before parsing; parseIcs now retries parsing after a targeted TypeError, preserving original signature.
Tests for Microsoft timezones tests/microsoft-timezone.test.ts	Adds tests covering retry flow, mapping coverage, recurrence cases, and various Microsoft timezone names; includes mocking of node-ical and some skipped tests.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Caller
  participant ICS as parseIcs
  participant NodeIcal as node-ical.parseICS
  participant Pre as Preprocessor (Windows→IANA)

  Caller->>ICS: parseIcs(ics)
  ICS->>NodeIcal: parseICS(ics)
  alt Parse succeeds
    NodeIcal-->>ICS: events
    ICS-->>Caller: events
  else TypeError with TZID (e.g., tz.startsWith)
    ICS->>Pre: preprocess(ics) // rewrite Windows TZIDs to IANA
    Pre-->>ICS: ics'
    ICS->>NodeIcal: parseICS(ics')
    alt Retry succeeds
      NodeIcal-->>ICS: events
      ICS-->>Caller: events
    else Retry fails
      ICS-->>Caller: throw combined error
    end
  else Other errors
    ICS-->>Caller: rethrow error
  end

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

I nibbled through zones from Redmond to Rome,
Mapping their names to IANA’s true home.
A hiccup? I retry—hop, parse, and glide,
With CLDR carrots tucked by my side.
Tests bloom like clover—green fields I see,
Time tastes delicious to a dev bunny. 🥕⏰

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix-microsoft-timezone-parsing

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 9d9becc and 85bbb7c.

⛔ Files ignored due to path filters (3)

• src/generated/windows-to-iana.json is excluded by !**/generated/**
• src/generated/windows-to-iana.yaml is excluded by !**/generated/**
• src/generated/windowsTimezones.ts is excluded by !**/generated/**

📒 Files selected for processing (4)

• package.json (1 hunks)
• scripts/update-timezones.js (1 hunks)
• src/icalUtils.ts (2 hunks)
• tests/microsoft-timezone.test.ts (1 hunks)

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