refactor(cache)!: move implementation classes out of the abstractions package

[cosmin-staicu]

Stacked on #215; its base is perf/breaking-hot-path. Review and merge that one first.

Moves the implementation classes from UiPath.Caching.Abstractions to UiPath.Caching, so the abstractions package keeps to interfaces, null implementations, DTOs and the extensions over them:

• SystemJsonByteSerializerProxy and RawByteSerializerProxy

• Cache<T>, HashCache<T> and CacheFactoryExtensions, which constructs them

• CacheExpiration, CacheKeyComparer and TelemetryTags

• BatchGetOrAdd, now public

Namespaces are unchanged, so code that references UiPath.Caching compiles as before. AddCaching already registers ICache<T> and IHashCache<T>, so a library that references only the abstractions package can inject typed caches without CreateCache<T>.

Batch GetOrAdd

• ICache's three batch GetOrAddAsync<T, TState> overloads lose their default bodies, which called BatchGetOrAdd.

• RedisCache and MultilayerCache already implement them. An implementation outside the library forwards to the public BatchGetOrAdd.RunAsync, which validates all four reference arguments synchronously, before the cache is touched.

• NullCache implements them with the result BatchGetOrAdd gives over a cache that never hits: the generator answers each key's first state, and states on the same key share that answer. A test checks that the two agree.

What stays

• Disposable: NullCacheChangeToken and NullTopic<T> return Disposable.Empty.

• The other extension classes: CacheExtensions, CacheSyncExtensions, HashCacheExtensions, HashCacheSyncExtensions and TimeProviderExtensions.

Breaking

• Code that references only UiPath.Caching.Abstractions and uses a moved class must add a UiPath.Caching reference, or inject ICache<T> and IHashCache<T> instead of calling CreateCache<T>.

• An ICache implementation outside the library must implement the three batch overloads.

• Binaries compiled against the old location or the old interface fail with TypeLoadException. The abstractions package cannot forward types to UiPath.Caching, which depends on it.

Verification

• dotnet build -c Release -warnaserror

• dotnet test: 4075 passed on net8.0 and net10.0, with the Redis integration tests on.

[github-actions]

🔎 Maintainer heads-up: automated triage flagged this PR as potentially material, so it may need a signed CLA in addition to the DCO sign-off.

Strong signals

• adds public API surface (PublicAPI.Unshipped.txt in src/UiPath.Caching.Abstractions, src/UiPath.Caching)

This is advisory only — the bot does not decide. Please judge against the CLA criteria (material, product-critical, patent-sensitive, corporate contributor, broad commercial use). Note that thresholds can be gamed by splitting PRs, so use your judgement.

• If a CLA is needed → add the cla-required label (a contributor comment with signing steps is posted automatically).
• If it is not needed → replace needs-cla-review with cla-not-required so later pushes don't re-flag it.

[Copilot]

Copilot review overview

🟡 Changes recommended

The public batch helper lacks consistent argument validation, and the interface documentation still shows removed default implementations.

Review effort: Balanced
Findings: 1

Open (1)

• Update ICache listing to remove obsolete default method bodies · New

What changed in this PR

Moves concrete cache implementations from UiPath.Caching.Abstractions into UiPath.Caching, preserving namespaces while enforcing a cleaner package boundary.

Changes:

• Relocates serializers, typed-cache wrappers, comparers, expiration helpers, and telemetry utilities.
• Makes BatchGetOrAdd public and requires external ICache implementations to provide batch overloads.
• Updates null-cache behavior, tests, API baselines, documentation, and migration notes.

File	Description
tests/​UiPath.Caching.Tests/​Fakes/​DictionaryCache.cs	Implements required batch overloads.
tests/​UiPath.Caching.Tests/​BatchGetOrAddTests.cs	Verifies null-cache batch equivalence.
src/​UiPath.Caching/​Telemetry/​TelemetryTags.cs	Moves telemetry tag conversion helper.
src/​UiPath.Caching/​SystemJsonByteSerializerProxy.cs	Moves the default JSON serializer.
src/​UiPath.Caching/​RawByteSerializerProxy.cs	Moves the raw-byte serializer.
src/​UiPath.Caching/​PublicAPI.Unshipped.txt	Records newly exposed core APIs.
src/​UiPath.Caching/​HashCacheOfT.cs	Moves the typed hash-cache wrapper.
src/​UiPath.Caching/​CacheOfT.cs	Moves the typed cache wrapper.
src/​UiPath.Caching/​CacheKeyComparer.cs	Moves cached key comparers.
src/​UiPath.Caching/​CacheFactoryExtensions.cs	Moves typed factory extensions.
src/​UiPath.Caching/​CacheExpiration.cs	Moves expiration validation helpers.
src/​UiPath.Caching/​BatchGetOrAdd.cs	Makes the batch helper public.
src/​UiPath.Caching.Abstractions/​PublicAPI.Unshipped.txt	Records removed and required APIs.
src/​UiPath.Caching.Abstractions/​NullCache.cs	Implements required batch operations.
src/​UiPath.Caching.Abstractions/​IHashCache.cs	Removes cross-package documentation reference.
src/​UiPath.Caching.Abstractions/​ICache.cs	Removes batch default implementations.
docs/​reference/​interfaces.md	Documents required batch methods and typed injection.
docs/​how-to/​extending.md	Documents serializer package ownership.
CHANGELOG.md	Records package and interface breaking changes.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

🔵 Needs a closer look

The newly public BatchGetOrAdd.RunAsync lacks deterministic validation for two required reference parameters.

Review effort: Balanced
Findings: None

Resolved since last review (1)

• Update ICache listing to remove obsolete default method bodies

[Copilot]

Copilot review overview

🔵 Needs a closer look

The broad assembly relocation and intentional binary-breaking interface changes warrant final human validation, especially because the PR is stacked on #215.

Review effort: Balanced
Findings: None

[Copilot]

Copilot review overview

🟡 Changes recommended

Interface documentation still incorrectly states that only ICache<T> lacks batch default implementations.

Review effort: Balanced
Findings: 1

Open (1)

• Update ICache<T> docs for removed default bodies · New

[Copilot]

Copilot review overview

🔵 Needs a closer look

The deliberate binary-breaking assembly and interface changes, combined with its stacked dependency on PR #215, warrant final human validation.

Review effort: Balanced
Findings: None

Resolved since last review (1)

• Update ICache<T> docs for removed default bodies

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
91.3% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

Copilot review overview

🟢 Approval recommended

The relocation preserves the public surface, and the intentional interface break is consistently implemented, tested, and documented.

Review effort: Balanced
Findings: None