[browser] atob polyfil for feature detection in V8

eng/pipelines/common/templates/wasm-runtime-tests.yml

@@ -49,7 +49,7 @@ jobs:
             testRunNamePrefixSuffix: Mono_$(_BuildConfig)
             testBuildArgs: /p:InstallV8ForTests=false
             # Build the runtime tests for browser, but don't send them to Helix to run on V8: the
-            # V8 baked into the helix-webassembly container doesn't support --experimental-wasm-exnref
+            # V8 baked into the helix-webassembly container doesn't support exnref
             # yet, so the tests abort at startup. Re-enable the run once the new V8 image is
             # available. See ActiveIssue https://github.com/dotnet/runtime/issues/129849
             sendToHelix: false

eng/pipelines/performance/runtime-wasm-perf.yml

@@ -5,7 +5,7 @@
 trigger: none
 
 # Disabled: the perf wasm v8 job installs V8 via jsvu, and the V8 binary it currently
-# installs does not support --experimental-wasm-exnref yet, so the MicroBenchmarks Helix
+# installs does not support exnref yet, so the MicroBenchmarks Helix
 # job aborts at startup. Re-enable once an exnref-capable V8 is pinned. See
 # ActiveIssue https://github.com/dotnet/runtime/issues/129849
 pr: none

eng/pipelines/runtime-linker-tests.yml

@@ -136,7 +136,7 @@ extends:
               - template: /eng/pipelines/libraries/execute-trimming-tests-steps.yml
                 parameters:
                     # Publish the trimmed browser apps, but don't run them on V8: the V8 baked into
-                    # the helix-webassembly container doesn't support --experimental-wasm-exnref yet,
+                    # the helix-webassembly container doesn't support exnref yet,
                     # so run-v8.sh aborts at startup. SkipTrimmingTestsRun keeps the build/publish
                     # coverage and only skips ExecuteApplications. Re-enable the run once the new V8
                     # image is available. See

src/mono/browser/build/BrowserWasmApp.targets

@@ -470,7 +470,7 @@
 
     <WriteLinesToFile
       File="$(WasmRunV8ScriptPath)"
-      Lines="$(V8ScriptShebang);v8 --experimental-wasm-exnref $(_WasmMainJSFileName) -- ${RUNTIME_ARGS} --run $(WasmMainAssemblyFileName) $*"
+      Lines="$(V8ScriptShebang);v8 $(_WasmMainJSFileName) -- ${RUNTIME_ARGS} --run $(WasmMainAssemblyFileName) $*"
       Overwrite="true">
     </WriteLinesToFile>
 

src/mono/browser/runtime/loader/polyfills.ts

@@ -35,6 +35,22 @@ export function verifyEnvironment () {
 }
 
 export async function detect_features_and_polyfill (module: DotnetModuleInternal): Promise<void> {
+    if (ENVIRONMENT_IS_SHELL) {
+        if (typeof globalThis.atob !== "function") {
+            const b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+            globalThis.atob = (input) => {
+                const str = String(input).replace(/=+$/, "");
+                let output = "";
+                for (let bc = 0, bs = 0, i = 0; i < str.length; i++) {
+                    const c = b64.indexOf(str.charAt(i));
+                    if (c === -1) continue;
+                    bs = bc % 4 ? bs * 64 + c : c;
+                    if (bc++ % 4) output += String.fromCharCode(255 & (bs >> ((-2 * bc) & 6)));
+                }
+                return output;
+            };
+        }
+    }
     if (ENVIRONMENT_IS_NODE) {
         // eslint-disable-next-line @typescript-eslint/ban-ts-comment
         // @ts-ignore:

src/mono/sample/wasm/console-v8/Wasm.Console.V8.Sample.csproj

@@ -5,7 +5,7 @@
     <WasmGenerateRunV8Script>true</WasmGenerateRunV8Script>
 
     <GenerateRunScriptForSample Condition="'$(ArchiveTests)' == 'true'">true</GenerateRunScriptForSample>
-    <RunScriptCommand>$(ExecXHarnessVar) wasm test --app=. --engine=V8 --engine-arg=--stack-trace-limit=1000 --engine-arg=--experimental-wasm-exnref --js-file=main.mjs --output-directory=$(XHarnessOutputVar)</RunScriptCommand>
+    <RunScriptCommand>$(ExecXHarnessVar) wasm test --app=. --engine=V8 --engine-arg=--stack-trace-limit=1000 --js-file=main.mjs --output-directory=$(XHarnessOutputVar)</RunScriptCommand>
   </PropertyGroup>
 
   <Target Name="RunSample" DependsOnTargets="RunSampleWithV8" />

src/mono/sample/wasm/wasm.mk

@@ -42,10 +42,10 @@ run-browser:
 	fi
 
 run-console:
-	cd bin/$(CONFIG)/wwwroot && $(V8_PATH) --stack-trace-limit=1000 --experimental-wasm-exnref --single-threaded $(MAIN_JS) -- $(ARGS)
+	cd bin/$(CONFIG)/wwwroot && $(V8_PATH) --stack-trace-limit=1000 --single-threaded $(MAIN_JS) -- $(ARGS)
 
 run-console-node:
-	cd bin/$(CONFIG)/wwwroot && node --stack-trace-limit=1000 --experimental-wasm-exnref --single-threaded $(MAIN_JS) $(ARGS)
+	cd bin/$(CONFIG)/wwwroot && node --stack-trace-limit=1000 --single-threaded $(MAIN_JS) $(ARGS)
 
 debug-console-node:
-	cd bin/$(CONFIG)/wwwroot && node --inspect=9222 --stack-trace-limit=1000 --experimental-wasm-exnref --single-threaded $(MAIN_JS) $(ARGS)
+	cd bin/$(CONFIG)/wwwroot && node --inspect=9222 --stack-trace-limit=1000 --single-threaded $(MAIN_JS) $(ARGS)

src/native/libs/Common/JavaScript/loader/dotnet.ts

@@ -11,12 +11,12 @@
 import type { DotnetHostBuilder } from "./types";
 
 import { HostBuilder } from "./host-builder";
-import { initPolyfillsAsync } from "./polyfills";
+import { initPolyfillsEarly } from "./polyfills";
 import { exit } from "./exit";
 import { dotnetInitializeModule } from ".";
 
 dotnetInitializeModule();
-await initPolyfillsAsync();
+await initPolyfillsEarly();
 
 export const dotnet: DotnetHostBuilder | undefined = new HostBuilder() as DotnetHostBuilder;
 export { exit };

src/native/libs/Common/JavaScript/loader/polyfills.ts

@@ -2,11 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 import { dotnetAssert } from "./cross-module";
-import { ENVIRONMENT_IS_NODE } from "./per-module";
+import { ENVIRONMENT_IS_NODE, ENVIRONMENT_IS_SHELL } from "./per-module";
 
 let hasFetch = false;
 
-export async function initPolyfills(): Promise<void> {
+export async function initPolyfillsLoader(): Promise<void> {
     if (ENVIRONMENT_IS_NODE) {
         await nodeFs();
         await nodeUrl();
@@ -17,7 +17,23 @@ export async function initPolyfills(): Promise<void> {
     }
 }
 
-export async function initPolyfillsAsync(): Promise<void> {
+export async function initPolyfillsEarly(): Promise<void> {
+    if (ENVIRONMENT_IS_SHELL) {
+        if (typeof globalThis.atob !== "function") {
+            const b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+            globalThis.atob = (input) => {
+                const str = String(input).replace(/=+$/, "");
+                let output = "";
+                for (let bc = 0, bs = 0, i = 0; i < str.length; i++) {
+                    const c = b64.indexOf(str.charAt(i));
+                    if (c === -1) continue;
+                    bs = bc % 4 ? bs * 64 + c : c;
+                    if (bc++ % 4) output += String.fromCharCode(255 & (bs >> ((-2 * bc) & 6)));
+                }
+                return output;
+            };
+        }
+    }
     if (ENVIRONMENT_IS_NODE) {
         if (!globalThis.crypto) {
             globalThis.crypto = <any>{};

src/native/libs/Common/JavaScript/loader/run.ts

@@ -9,7 +9,7 @@ import { createPromiseCompletionSource } from "./promise-completion-source";
 import { getIcuResourceName } from "./icu";
 import { loaderConfig, validateLoaderConfig } from "./config";
 import { fetchAssembly, fetchIcu, fetchNativeSymbols, fetchPdb, fetchSatelliteAssemblies, fetchVfs, fetchMainWasm, loadDotnetModule, loadJSModule, nativeModulePromiseController, verifyAllAssetsDownloaded, callLibraryInitializerOnRuntimeReady, callLibraryInitializerOnRuntimeConfigLoaded, prefetchAllResources, prefetchJSModuleLinks, resolveAllDownloadsQueued } from "./assets";
-import { initPolyfills } from "./polyfills";
+import { initPolyfillsLoader } from "./polyfills";
 import { validateEngineFeatures } from "./bootstrap";
 
 const runMainPromiseController = createPromiseCompletionSource<number>();
@@ -90,7 +90,7 @@ export async function createRuntime(downloadOnly: boolean, httpCacheOnly: boolea
             }
 
             // after onConfigLoaded hooks that could install polyfills, our polyfills can be initialized
-            await initPolyfills();
+            await initPolyfillsLoader();
 
             configInitialized = true;
             modulesAfterConfigLoadedCache = modulesAfterConfigLoadedPromises;