Post place lookups: Using static file on CDN

[olemartinorg]

Description

This tests out an alternative fix for the recent post place lookup problem. Instead of relying on the APIs from Posten/Bring (which have been down today and yesterday), and the quickfix for using an older NPM package (#3943), this has an alternative approach discussed during a meeting today.

The plan is to place a static file on CDN the frontend can download whenever lookups are needed. I managed to get the file down to ~13kb when brotli compressed, using a two-stage lookup to get from zip code to post place from a fairly simple JSON structure. We should be able to keep this file up-to-date on CDN via a script that downloads and re-codes the source - something we can run periodically. We trust our own CDN to be as available as our frontend already is.

Related Issue(s)

• Replacing post code API with package from npm #3943
• Backporting #3943 #3946
• fix: Remove post place API call and make field writable #3944
• https://github.com/Altinn/altinn-support-private/issues/4971
• https://digdir.slack.com/archives/C07A81Z9TCZ/p1768309052386309
• Adding workflow for downloading postcode registry altinn-cdn#274
• Update postcodes registry altinn-cdn#275

Verification/QA

• Manual functionality testing
  • I have tested these changes manually
  • Creator of the original issue (or service owner) has been contacted for manual testing (or will be contacted when released in alpha)
  • No testing done/necessary
• Automated tests
  • Unit test(s) have been added/updated
  • Cypress E2E test(s) have been added/updated
  • No automatic tests are needed here (no functional changes/additions)
  • I want someone to help me make some tests
• UU/WCAG (follow these guidelines until we have our own)
  • I have tested with a screen reader/keyboard navigation/automated wcag validator
  • No testing done/necessary (no DOM/visual changes)
  • I want someone to help me perform accessibility testing
• User documentation @ altinn-studio-docs
  • Has been added/updated
  • No functionality has been changed/added, so no documentation is needed
  • I will do that later/have created an issue
• Support in Altinn Studio
  • Issue(s) created for support in Studio
  • This change/feature does not require any changes to Altinn Studio
• Sprint board
  • The original issue (or this PR itself) has been added to the Team Apps project and to the current sprint board
  • I don't have permissions to do that, please help me out
• Labels
  • I have added a kind/* and backport* label to this PR for proper release notes grouping
  • I don't have permissions to add labels, please help me out

Summary by CodeRabbit

• Chores
  • Removed the norway-postal-codes package dependency. Updated postal code data fetching to retrieve from an external registry instead of a bundled library.

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

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR removes the "norway-postal-codes" npm dependency and replaces it with a data-fetching approach. Postal code data is now fetched from an external URL using React Query instead of being bundled as a package. Supporting changes include adding new types, query functions, URL constants, test mocks, and updating related test assertions.

Changes

Cohort / File(s)	Summary
Dependency Removal package.json	Removed "norway-postal-codes": "^4.1.0" from dependencies
Type and URL Definitions src/types/shared.ts, src/utils/urls/appUrlHelper.ts	Added PostalCodesRegistry interface with places and mapping properties; added postalCodesUrl constant pointing to external registry endpoint
Query Layer src/queries/queries.ts	Introduced new fetchPostalCodes function returning PostalCodesRegistry via axios call to postalCodesUrl
Hook Migration src/layout/Address/usePostPlace.ts	Replaced local package lookup with React Query-based data fetching; added helper logic to resolve zip to place from fetched data
Test Infrastructure src/test/renderWithProviders.tsx	Added defaultPostalCodesMock with indexed format containing places and mapping arrays; extended defaultQueryMocks with fetchPostalCodes
Test Updates src/layout/Address/AddressComponent.test.tsx	Removed jest.mock block for norway-postal-codes
E2E Test Adjustment test/e2e/integration/multiple-datamodels-test/saving.ts	Updated save request count expectation from exactly 4 to a range of 4-5

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• Replacing post code API with package from npm #3943: Modifies the same postal-code lookup logic paths (usePostPlace.ts, queries, package.json, tests) but implements the opposite approach using the norway-postal-codes package instead of external data fetching.

Suggested reviewers

• ErlingHauan

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately captures the main change: replacing runtime API calls with a static CDN file for postal code lookups.
Description check	✅ Passed	The pull request provides a comprehensive description with clear context, motivation, related issues, and verification checklist mostly completed.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/post-number-registry

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[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
90.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

⚠️ Automatic backport failed due to conflicts

The automatic backport to release/v4.24 failed because of merge conflicts.

The release branch release/v4.24 already existed and was updated.

Manual backport required:

# Checkout the release branch
git checkout release/v4.24
git pull origin release/v4.24

# Create backport branch
git checkout -b backport/3947

# Cherry-pick the merge commit
git cherry-pick dffa0fc410641cbaff05ba32f06425e85c52c490

# Resolve conflicts, then:
git add .
git cherry-pick --continue

# Push and create PR
git push origin backport/3947