[browser][coreCLR] throttling + WBT

[pavelsavara]

• enable throttling for all file types.
• leaveThrottling(); after instantiation for some of them
• add optional asset.priority for later use
• make sure that onDownloadedAsset(); is counted even when it fails
• fix webcil name

Fixes #124900

[dotnet-policy-service]

Tagging subscribers to this area: @agocke, @jeffschwMSFT, @elinor-fung
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[Copilot]

Pull request overview

This pull request refactors the download throttling mechanism in the browser WASM loader. The main changes include renaming the "webcil10" asset behavior to "webcil", splitting the old noThrottleNoRetry map into separate noRetry and noBuffer maps, and restructuring throttling logic to better handle assets that don't buffer immediately (such as dotnetwasm, webcil, and symbols).

Changes:

• Renamed "webcil10" to "webcil" (breaking API change) in public-api.ts and dotnet.d.ts
• Added priority field to AssetEntryInternal for potential future priority-based download handling
• Refactored fetchWasm to fetchMainWasm and restructured throttling logic with new enterThrottling() and leaveThrottling() helper functions
• Split old noThrottleNoRetry map into noRetry (for disabling retries) and noBuffer (for skipping immediate buffering)
• Added try-finally blocks to fetch functions for better error handling and resource cleanup

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/native/libs/Common/JavaScript/types/public-api.ts	Renamed "webcil10" to "webcil" in AssetBehaviors type (breaking change)
src/native/libs/Common/JavaScript/types/internal.ts	Added optional priority field to AssetEntryInternal for throttling bypass
src/native/libs/Common/JavaScript/loader/run.ts	Updated import and call from fetchWasm to fetchMainWasm
src/native/libs/Common/JavaScript/loader/dotnet.d.ts	Renamed "webcil10" to "webcil" in type definitions (breaking change)
src/native/libs/Common/JavaScript/loader/assets.ts	Major refactoring: renamed fetchWasm to fetchMainWasm, extracted enterThrottling/leaveThrottling helpers, split noThrottleNoRetry into noRetry and noBuffer maps, added try-finally blocks for error handling, and updated webcil10 references to webcil

[Copilot]

Pull request overview

Copilot reviewed 13 out of 14 changed files in this pull request and generated 9 comments.

[Copilot]

Pull request overview

Copilot reviewed 16 out of 17 changed files in this pull request and generated 4 comments.

Comments suppressed due to low confidence (2)

src/native/libs/Common/JavaScript/loader/assets.ts:504

• onDownloadedAsset assigns asset.buffer = null!, which sidesteps the declared type (ArrayBuffer | Promise<ArrayBuffer> | undefined) and forces a non-null assertion. Consider setting it to undefined instead so the runtime value matches the type and you can drop the null! cast while still releasing memory.

    // release memory
    asset.buffer = null!;
    asset.pendingDownload = undefined;

src/native/libs/Common/JavaScript/types/internal.ts:65

• The newly introduced inprogress field is inconsistent with the existing camelCase naming (e.g., useCredentials, pendingDownload). Consider renaming it to inProgress (and updating its uses) to keep naming consistent and reduce confusion.

    priority?: boolean
    shortName?: string
    inprogress?: boolean
}

[Copilot]

Pull request overview

Copilot reviewed 16 out of 17 changed files in this pull request and generated 5 comments.

[pavelsavara]

Passing test Log

[log] TestOutput -> Fetch started. Active downloads: 4
[log] TestOutput -> Fetch completed. Active downloads: 3
[log] TestOutput -> Fetch completed. Active downloads: 2
[log] TestOutput -> Fetch completed. Active downloads: 1
[log] TestOutput -> Fetch completed. Active downloads: 0
[log] TestOutput -> Fetch started. Active downloads: 1
[log] TestOutput -> Fetch started. Active downloads: 2
[log] TestOutput -> Fetch started. Active downloads: 3
[log] TestOutput -> Fetch completed. Active downloads: 2
[log] TestOutput -> Fetch completed. Active downloads: 1
[log] TestOutput -> Fetch completed. Active downloads: 0
Exited with 0
[log] WASM EXIT 0
Browser has been disconnected
    Wasm.Build.Tests.MaxParallelDownloadsTests.NeverFetchMoreThanMaxAllowed(config: Release, maxParallelDownloads: "4") [FINISHED] Time: 23.5878307s

[Copilot]

Pull request overview

Copilot reviewed 18 out of 19 changed files in this pull request and generated 1 comment.

[ilonatommy]

Minor improvements.

[maraf]

+1 on Ilona's comments

[pavelsavara]

/ba-g bad exit infra failures