Handle URL string icons

[puneetdixit200]

Summary

• Allow Activity Vocabulary icon URL strings to decode as Link values instead of remote Image document references.
• Keep WebFinger avatar generation working for both Image.url and Link.href icons.
• Refresh generated vocab-tools snapshots for Deno, Node, and Bun.

Fixes: #420

Verification

• docker run --rm -v "$PWD":/workspace -w /workspace denoland/deno:2.7.13 deno task -f @fedify/vocab compile
• docker run --rm -v "$PWD":/workspace -w /workspace/packages/vocab denoland/deno:2.7.13 deno test --allow-read --allow-write --allow-env --unstable-kv --trace-leaks --filter "URL string icon" src/vocab.test.ts
• docker run --rm -v "$PWD":/workspace -w /workspace/packages/vocab denoland/deno:2.7.13 deno test --allow-read --allow-write --allow-env --unstable-kv --trace-leaks --filter "relative URLs" src/vocab.test.ts
• docker run --rm -v "$PWD":/workspace -w /workspace/packages/fedify denoland/deno:2.7.13 deno test --check --doc --allow-read --allow-write --allow-env --unstable-kv --trace-leaks src/federation/webfinger.test.ts
• docker run --rm -v "$PWD":/workspace -w /workspace/packages/vocab-tools denoland/deno:2.7.13 deno test -A
• node --experimental-transform-types --test src/class.test.ts from packages/vocab-tools
• bun test --timeout 15000 src/class.test.ts from packages/vocab-tools
• docker run --rm -v "$PWD":/workspace -w /workspace denoland/deno:2.7.13 deno fmt --check CHANGES.md packages/fedify/src/federation/webfinger.ts packages/vocab-tools/src/codec.ts packages/vocab-tools/src/property.ts packages/vocab/src/vocab.test.ts
• docker run --rm -v "$PWD":/workspace -w /workspace denoland/deno:2.7.13 deno lint packages/fedify/src/federation/webfinger.ts packages/vocab-tools/src/codec.ts packages/vocab-tools/src/property.ts packages/vocab/src/vocab.test.ts
• docker run --rm -v "$PWD":/workspace -w /workspace denoland/deno:2.7.13 deno check packages/fedify/src/federation/webfinger.ts packages/vocab-tools/src/codec.ts packages/vocab-tools/src/property.ts packages/vocab/src/vocab.test.ts
• git diff --check

AI usage

This change and PR description were assisted by OpenAI GPT-5. The commit includes the required Assisted-by: OpenAI GPT-5:gpt-5 trailer.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 6cf8bb17-45ef-4648-b2eb-91e0097195b5

📥 Commits

Reviewing files that changed from the base of the PR and between 8db5848 and 3659106.

⛔ Files ignored due to path filters (3)

• packages/vocab-tools/src/__snapshots__/class.test.ts.deno.snap is excluded by !**/*.snap
• packages/vocab-tools/src/__snapshots__/class.test.ts.node.snap is excluded by !**/*.snap
• packages/vocab-tools/src/__snapshots__/class.test.ts.snap is excluded by !**/*.snap

📒 Files selected for processing (6)

• CHANGES.md
• packages/fedify/src/federation/webfinger.ts
• packages/vocab-tools/src/codec.ts
• packages/vocab-tools/src/property.ts
• packages/vocab/src/object.yaml
• packages/vocab/src/vocab.test.ts

---

📝 Walkthrough

Walkthrough

This PR extends Fedify's icon property to accept both Link and Image types per ActivityStreams 2.0 specification, fixing a bug where URL strings for icon properties caused JSON parsing errors. The JSON-LD decoder is updated to conditionally wrap bare @id values into Link objects when appropriate, WebFinger is integrated to handle the new type, and test coverage validates the behavior.

Changes

Icon property Link and Image support

Layer / File(s)	Summary
Vocabulary schema update packages/vocab/src/object.yaml	The icon property's range is extended to include both https://www.w3.org/ns/activitystreams#Link and https://www.w3.org/ns/activitystreams#Image.
JSON-LD decoder code generation packages/vocab-tools/src/codec.ts, packages/vocab-tools/src/property.ts	IRI constants for ActivityStreams Link, Object, and xsd:anyURI are added. A per-property decodeBareIdAsLink flag is computed when the range includes Link but excludes Object and anyURI. When true, bare @id-only JSON objects are wrapped into new Link({ href }) instead of plain URL instances. Template punctuation is adjusted for multi-range decoder generation.
WebFinger avatar extraction packages/fedify/src/federation/webfinger.ts	Icon handling for actor WebFinger links now supports both LinkObject instances (extracting .href) and URL-like objects (extracting .url), then stringifies consistently as href.href.toString() with optional mediaType.
Test regression and assertions packages/vocab/src/vocab.test.ts	A new test verifies that Person.fromJsonLd() treats URL-string icons as Link instances without dereferencing. Existing icon tests replace optional-chain URL checks with strict assertInstanceOf(..., Image) and direct icon.url comparisons.
Release notes CHANGES.md	Version 2.3.0 changelog documents the @fedify/vocab fix: icon URL strings are now exposed as Link instances rather than dereferenced Image documents.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested labels

component/federation, activitypub/interop

Suggested reviewers

• sij411
• 2chanhaeng

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Handle URL string icons' is concise and directly describes the main change: supporting URL string icons instead of only Image objects.
Description check	✅ Passed	The description clearly explains the changes: allowing icon URL strings to decode as Link values, keeping WebFinger working for both Image and Link icons, and references issue #420.
Linked Issues check	✅ Passed	The PR addresses issue #420 by updating the icon property range to include Link, modifying codec generation to decode bare @id values as Link objects, and updating WebFinger to handle both Image.url and Link.href icons.
Out of Scope Changes check	✅ Passed	All changes are directly related to handling URL string icons: vocabulary schema updates, codec generation logic, WebFinger handling, and corresponding tests. No unrelated changes detected.

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[gemini-code-assist]

Code Review

This pull request fixes an issue where URL strings in Activity Vocabulary icon values were incorrectly dereferenced as remote Image documents. The icon property range in object.yaml now includes Link, and the vocab-tools decoder has been updated to handle bare IDs as Link instances when appropriate. Additionally, the WebFinger implementation was updated to support these changes, and new tests were added to verify that string-based icons are correctly parsed as links without being dereferenced. I have no feedback to provide as there were no review comments.