[browser][coreCLR] running main/exit/abort/logging and infra for unit testing

[pavelsavara]

• Added dotnet.runMainAndExit() and dotnet.runMain() APIs. For Mono too.
• make dotnet.run() to not call exit() and keep runtime alive, only for CoreCLR
  • This will be breaking change for CoreCLR vs Mono.
  • Because previous behavior was just confusing everyone.
  • Make it deprecated and point to runMain()
• new internal MSbuild property <WasmTestSupport>true</WasmTestSupport> which deploys dotnet.diagnostics.js
• load dotnet.diagnostics.js early when available in the boot config
• add internal support for unit testing via dotnet.diagnostics.js
  • skeleton of symbolicateStackTrace
  • exitOnUnhandledError
  • appendElementOnExit
  • logExitCode
  • asyncFlushOnExit
  • forwardConsole
• new internal MSbuild properties WasmTestExitOnUnhandledError, WasmTestAppendElementOnExit, WasmTestLogExitCode, WasmTestAsyncFlushOnExit, WasmTestForwardConsole
• set WasmTestSupport for library tests and WBT
• set -sEXIT_RUNTIME=1 - this enables C++ global destructors
• implemented abortStartup(), abortTimers(), abortPosix()
• implemented isExited(), isRuntimeRunning()
• invoke LoadBootResourceCallback for Blazor
• invoke Module.onConfigLoaded and Module.onDotnetReady
• captures ExitStatus type
• capture posix/emscripten abort()/exit() events
• fixed locateFile - for query string propagation
• hides BrowserHost_InitializeCoreCLR, BrowserHost_ExecuteAssembly from Module exports
• reporting not found assemblies to debug log

Fixes#101169
Fixes#75335
On top of #122616
On top of #122495

[Copilot]

Pull request overview

This PR adds comprehensive exit/abort/logging infrastructure for unit testing in browser/CoreCLR environments, enabling better diagnostics and test harness integration.

Key Changes:

• Introduces new test instrumentation via dotnet.diagnostics.js module with exit handlers, console forwarding, and symbolication skeleton
• Breaking API change: dotnet.run() now keeps the runtime alive; new dotnet.runAndExit() method exits runtime after Main() completes
• Adds internal MSBuild properties (WasmTestSupport, WasmTestExitOnUnhandledError, etc.) to control test behavior and diagnostics deployment

Reviewed changes

Copilot reviewed 37 out of 38 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/tasks/Microsoft.NET.Sdk.WebAssembly.Pack.Tasks/GenerateWasmBootJson.cs	Adds five new boolean properties for test instrumentation flags, gated by version 11.0+
src/tasks/Microsoft.NET.Sdk.WebAssembly.Pack.Tasks/BootJsonData.cs	Defines the five new test instrumentation properties in boot config JSON schema
src/native/libs/System.Native.Browser/utils/index.ts	Replaces exit export with abortTimers and abortPosix for better separation of concerns
src/native/libs/System.Native.Browser/utils/host.ts	Removes old exit() function, adds abortTimers() and abortPosix() for cleanup
src/native/libs/System.Native.Browser/native/cross-linked.ts	Declares global ABORT and EXITSTATUS variables for emscripten integration
src/native/libs/System.Native.Browser/diagnostics/types.ts	New file defining types for marshaling, diagnostics exports, and measured blocks
src/native/libs/System.Native.Browser/diagnostics/symbolicate.ts	Skeleton implementation of stack trace symbolication (placeholder for future work)
src/native/libs/System.Native.Browser/diagnostics/per-module.ts	Re-exports common per-module definitions for diagnostics
src/native/libs/System.Native.Browser/diagnostics/index.ts	Main entry point for diagnostics module initialization
src/native/libs/System.Native.Browser/diagnostics/exit.ts	Implements exit handlers, unhandled error handlers, and exit code logging
src/native/libs/System.Native.Browser/diagnostics/cross-module.ts	Re-exports common cross-module definitions for diagnostics
src/native/libs/System.Native.Browser/diagnostics/console-proxy.ts	Implements console forwarding to WebSocket for test runners
src/native/libs/Common/JavaScript/types/public-api.ts	Updates API: removes withConfigSrc() docs, adds run() and runAndExit() with clear behavior distinction
src/native/libs/Common/JavaScript/types/internal.ts	Adds DiagnosticsExportsTable to internal exchange, updates asset entry fields, adds OnExitListener type
src/native/libs/Common/JavaScript/types/exchange.ts	Adds diagnostics exports, exit lifecycle functions, and additional browser host exports
src/native/libs/Common/JavaScript/cross-module/index.ts	Integrates diagnostics exports into cross-module exchange system
src/native/libs/Common/JavaScript/CMakeLists.txt	Adds new diagnostics TypeScript source files to build
src/native/corehost/browserhost/loader/run.ts	Major refactoring: moves runtime creation logic here, adds createRuntime() and abortStartup(), improved initializeCoreCLR()
src/native/corehost/browserhost/loader/lib-initializers.ts	Adds comment clarifying expected function names
src/native/corehost/browserhost/loader/index.ts	Registers exit handlers, adds exit-related exports, changes default runtimeId to undefined
src/native/corehost/browserhost/loader/host-builder.ts	Implements new run() (keeps runtime alive) and runAndExit() methods, exports loadBootResourceCallback
src/native/corehost/browserhost/loader/exit.ts	Complete rewrite with runtimeState, exit listeners, Emscripten integration, proper exit/abort handling
src/native/corehost/browserhost/loader/dotnet.d.ts	Updates type definitions for run() and runAndExit() methods, removes withConfigSrc()
src/native/corehost/browserhost/loader/config.ts	Renames netLoaderConfig to loaderConfig for consistency
src/native/corehost/browserhost/loader/bootstrap.ts	Fixes locateFile() to properly handle query strings for modules vs. assets
src/native/corehost/browserhost/loader/assets.ts	Moves runtime creation to run.ts, implements Blazor loadBootResourceCallback support, adds proper cache/integrity handling
src/native/corehost/browserhost/libBrowserHost.footer.js	Hides BrowserHost_InitializeCoreCLR and BrowserHost_ExecuteAssembly from Module exports
src/native/corehost/browserhost/host/index.ts	Exports getExitStatus and initializeCoreCLR functions
src/native/corehost/browserhost/host/host.ts	Implements getExitStatus(), initializeCoreCLR(), improves assembly probing with debug logging, refactors runMain() and runMainAndExit() error handling
src/native/corehost/browserhost/host/cross-linked.ts	Declares _BrowserHost_InitializeCoreCLR, _BrowserHost_ExecuteAssembly, and ExitStatus globals
src/native/corehost/browserhost/CMakeLists.txt	Removes specific functions from exported list, relying on generic export configuration
src/mono/wasm/testassets/WasmBrowserRunMainOnly/wwwroot/main.js	Simplifies to single runAndExit() call instead of manual error handling
src/mono/wasm/testassets/WasmBrowserRunMainOnly/WasmBrowserRunMainOnly.csproj	Enables all test instrumentation flags
src/mono/wasm/Wasm.Build.Tests/Common/BuildEnvironment.cs	Enables WasmTestSupport for CoreCLR builds
src/mono/sample/wasm/Directory.Build.targets	Adds test support properties to nested build
src/mono/nuget/Microsoft.NET.Sdk.WebAssembly.Pack/build/Microsoft.NET.Sdk.WebAssembly.Browser.targets	Wires up test instrumentation properties to boot config generation, conditionally includes diagnostics module
src/mono/browser/test-main.js	Changes default forwardConsole to only enable on Firefox (not for other browsers in debug mode)
eng/testing/tests.browser.targets	Enables WasmTestSupport for CoreCLR library tests

[javiercn]

Looks good to me. Is it fair to assume that most of the testing is essentially existing tests continue to pass?

[pavelsavara]

/ba-g unrelated failures