Add runtimeconfig.json support for WebAssembly (#56486)

* Initial change for adding runtimeconfig to wasm

* Add runtimeconfig support to wasm

* Move test folder and update runtimeconifg task name

* Fix test

* Fix test csproj file

* Use the right var for main dll name

* Resolve review feedback part 1

* Resolve review feedbacks part 2

* Add doc for updating dependencies when adding new tasks

* Remove redundant condition and redundant copy

* There is no runtimeconfig.json file to parse, when OutputType is library. So skip it.

* Skip for Android tests as well.

* Remove the wrong locatioin of WasmFilesToIncludeInFileSystem

* Update runtimeconfig file path

* Add RuntimeConfigParserTasksAssemblyPath to linker test project template

* Fix test failures on WASM EAT and AOT lanes

* [wasm] Add a test for reading runtimeconfig.json

* improve error reporting slightly

* Enable tests

* One more thing to enable tests

* Run target _WasmGenerateRuntimeConfig when runtimeconfig.json file exists

* Add a test for configure runtime using msbuild properties

* Fix runtime test failures

* Update tests base on feedback

* Add missing ")"

* Add one more condition

* More format changes

* Better error handling

* [wasm] Fix build for a test support project

This fixes the build for ApplyUpdateReferencedAssembly.csproj, which is
a support project for HotReload wasm functional test.

```
D:\workspace\_work\1\s\src\mono\wasm\build\WasmApp.targets(131,5): error : Could not find
    D:\workspace\_work\1\s\artifacts\bin\ApplyUpdateReferencedAssembly\net6.0-Release\browser-wasm\publish\ApplyUpdateReferencedAssembly.runtimeconfig.json
    for D:\workspace\_work\1\s\artifacts\bin\ApplyUpdateReferencedAssembly\net6.0-Release\browser-wasm\publish\ApplyUpdateReferencedAssembly.dll.

    [D:\workspace\_work\1\s\src\tests\FunctionalTests\WebAssembly\Browser\HotReload\ApplyUpdateReferencedAssembly\ApplyUpdateReferencedAssembly.csproj]
```

The wasm targets should be run at all for this project. But they are run
because they get imported by tests.wasm.targets, which gets imported because
`$(IsTestProject)=true`.

The csproj has `$(IsTestProject)=false`, and `$(IsTestSupportProject)=true`,
which should mean that the test.props/targets don't get imported. But the
import is conditioned on `$(EnableTestSupport)`, which gets set in
`src/libraries/Directory.Build.props`. And that means setting
`$(IsTestProject)=true` in the csproj is too late.

So, instead, set that in a `Directory.Build.props`. And also, ensure that the
`Directory.Build.props` for functional tests doesn't override the value!

Co-authored-by: Ankit Jain <radical@gmail.com>

eng/testing/linker/project.csproj.template

@@ -7,6 +7,7 @@
     <MonoAOTCompilerTasksAssemblyPath>{MonoAOTCompilerTasksAssemblyPath}</MonoAOTCompilerTasksAssemblyPath>
     <WasmAppBuilderTasksAssemblyPath>{WasmAppBuilderTasksAssemblyPath}</WasmAppBuilderTasksAssemblyPath>
     <JsonToItemsTaskFactoryTasksAssemblyPath>{JsonToItemsTaskFactoryTasksAssemblyPath}</JsonToItemsTaskFactoryTasksAssemblyPath>
+    <RuntimeConfigParserTasksAssemblyPath>{RuntimeConfigParserTasksAssemblyPath}</RuntimeConfigParserTasksAssemblyPath>
     <MicrosoftNetCoreAppRuntimePackRidDir>{MicrosoftNetCoreAppRuntimePackRidDir}</MicrosoftNetCoreAppRuntimePackRidDir>
     <RepositoryEngineeringDir>{RepositoryEngineeringDir}</RepositoryEngineeringDir>
     <TargetFramework>{TestTargetFramework}</TargetFramework>

eng/testing/linker/trimmingTests.targets

@@ -97,6 +97,7 @@
                                                  .Replace('{MonoProjectRoot}', '$(MonoProjectRoot)')
                                                  .Replace('{MonoAOTCompilerTasksAssemblyPath}', '$(MonoAOTCompilerTasksAssemblyPath)')
                                                  .Replace('{JsonToItemsTaskFactoryTasksAssemblyPath}', '$(JsonToItemsTaskFactoryTasksAssemblyPath)')
+                                                 .Replace('{RuntimeConfigParserTasksAssemblyPath}', '$(RuntimeConfigParserTasksAssemblyPath)')
                                                  .Replace('{WasmAppBuilderTasksAssemblyPath}', '$(WasmAppBuilderTasksAssemblyPath)')
                                                  .Replace('{MicrosoftNetCoreAppRuntimePackRidDir}', '$(MicrosoftNetCoreAppRuntimePackRidDir)'))"
                       Overwrite="true" />

eng/testing/tests.mobile.targets

@@ -54,13 +54,13 @@
              AssemblyFile="$(RuntimeConfigParserTasksAssemblyPath)"
              Condition="'$(RuntimeConfigParserTasksAssemblyPath)' != ''" />
 
-  <Target Name="GenerateRuntimeConfig">
+  <Target Name="GenerateRuntimeConfig" Condition="'$(OutputType)' != 'library' and '$(TargetOS)' != 'Browser'">
     <PropertyGroup>
       <RuntimeConfigFilePath>$(PublishDir)$(AssemblyName).runtimeconfig.json</RuntimeConfigFilePath>
       <ParsedRuntimeConfigFilePath>$(PublishDir)runtimeconfig.bin</ParsedRuntimeConfigFilePath>
     </PropertyGroup>
 
-    <ItemGroup Condition="'$(RunAOTCompilation)' == 'true'">
+    <ItemGroup>
       <RuntimeConfigReservedProperties Include="RUNTIME_IDENTIFIER"/>
       <RuntimeConfigReservedProperties Include="APP_CONTEXT_BASE_DIRECTORY"/>
     </ItemGroup>

eng/testing/tests.wasm.targets

@@ -75,9 +75,15 @@
              AssemblyFile="$(WasmBuildTasksAssemblyPath)" />
 
   <Target Name="_BundleAOTTestWasmAppForHelix" DependsOnTargets="PrepareForWasmBuildApp">
+    <PropertyGroup>
+      <_MainAssemblyPath Condition="'%(WasmAssembliesToBundle.FileName)' == $(AssemblyName) and '%(WasmAssembliesToBundle.Extension)' == '.dll'">%(WasmAssembliesToBundle.Identity)</_MainAssemblyPath>
+      <RuntimeConfigFilePath>$([System.IO.Path]::ChangeExtension($(_MainAssemblyPath), '.runtimeconfig.json'))</RuntimeConfigFilePath>
+    </PropertyGroup>
+
     <ItemGroup>
       <BundleFiles Include="$(WasmMainJSPath)"                  TargetDir="publish" />
       <BundleFiles Include="@(WasmAssembliesToBundle)"          TargetDir="publish\%(WasmAssembliesToBundle.RecursiveDir)" />
+      <BundleFiles Include="$(RuntimeConfigFilePath)"           TargetDir="publish" />
 
       <BundleFiles Include="$(MonoProjectRoot)\wasm\data\aot-tests\*" TargetDir="publish" />
     </ItemGroup>
@@ -99,6 +105,7 @@
       <_WasmPropertyNames Include="WasmLinkIcalls" />
       <_WasmPropertyNames Include="WasmDedup" />
       <_WasmPropertyNames Include="IncludeSatelliteAssembliesInVFS" />
+      <_WasmPropertyNames Include="AssemblyName" />
 
       <_WasmPropertiesToPass
         Include="$(%(_WasmPropertyNames.Identity))"

src/libraries/System.Diagnostics.DiagnosticSource/tests/TestWithConfigSwitches/System.Diagnostics.DiagnosticSource.Switches.Tests.csproj

@@ -2,7 +2,6 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
     <TestRuntime>true</TestRuntime>
-    <IgnoreForCI Condition="'$(TargetOS)' == 'Browser'">true</IgnoreForCI> <!-- remove once https://github.com/dotnet/runtime/issues/38433 is fixed -->
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="ActivityTests.cs" />

src/libraries/System.Text.Encoding/tests/Encoding/Encoding.cs

@@ -64,7 +64,6 @@ public static void GetEncodingsTest()
             }
         }
 
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
         [Theory]
         [MemberData(nameof(Encoding_TestData))]
         public static void VerifyCodePageAttributes(int codepage, string name, string bodyName, string headerName, bool isBrowserDisplay,
@@ -81,7 +80,6 @@ public static void VerifyCodePageAttributes(int codepage, string name, string bo
             Assert.Equal(windowsCodePage, encoding.WindowsCodePage);
         }
 
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
         [Theory]
         [MemberData(nameof(Normalization_TestData))]
         public static void NormalizationTest(int codepage, bool normalized, bool normalizedC, bool normalizedD, bool normalizedKC, bool normalizedKD)

src/libraries/System.Text.Encoding/tests/Encoding/EncodingGetEncodingTests.cs

@@ -88,7 +88,6 @@ public CodePageMapping(string name, int codepage)
             new CodePageMapping("x-unicode-2-0-utf-8", 65001)
         };
 
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
         [Fact]
         public void TestEncodingNameAndCopdepageNumber()
         {
@@ -99,7 +98,6 @@ public void TestEncodingNameAndCopdepageNumber()
             }
         }
 
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
         [Fact]
         public void GetEncoding_EncodingName()
         {
@@ -119,7 +117,6 @@ public void GetEncoding_EncodingName()
             }
         }
 
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
         [Fact]
         public void GetEncoding_WebName()
         {

src/libraries/System.Text.Encoding/tests/UTF7Encoding/UTF7EncodingEncode.cs

@@ -6,7 +6,6 @@
 
 namespace System.Text.Tests
 {
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
     public class UTF7EncodingEncode
     {
         public static IEnumerable<object[]> Encode_Basic_TestData()

src/libraries/System.Text.Encoding/tests/UTF7Encoding/UTF7EncodingTests.cs

@@ -6,7 +6,6 @@
 
 namespace System.Text.Tests
 {
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/38433", TestPlatforms.Browser)] // wasm doesn't honor runtimeconfig.json
     public class UTF7EncodingTests
     {
         [Fact]

src/libraries/sendtohelixhelp.proj

@@ -370,6 +370,7 @@
       <HelixCorrelationPayload Include="$(WasmBuildTargetsDir)"                  Destination="build/wasm" />
       <HelixCorrelationPayload Include="$(MonoAotCrossDir)"                      Destination="build/cross" />
       <HelixCorrelationPayload Include="$(JsonToItemsTaskFactoryDir)"            Destination="build/JsonToItemsTaskFactory" />
+      <HelixCorrelationPayload Include="$(RuntimeConfigParserDir)"               Destination="build/RuntimeConfigParser" />
     </ItemGroup>
 
     <ItemGroup Condition="'$(TargetOS)' == 'Browser' and '$(Scenario)' != 'BuildWasmApps'">

src/libraries/tests.proj

@@ -253,9 +253,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.Xml\tests\System.Security.Cryptography.Xml.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.X509Certificates\tests\System.Security.Cryptography.X509Certificates.Tests.csproj" />
 
-    <!-- https://github.com/dotnet/runtime/issues/38433 -->
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Diagnostics.DiagnosticSource/tests/TestWithConfigSwitches/System.Diagnostics.DiagnosticSource.Switches.Tests.csproj" />
-
     <!-- Issue: https://github.com/dotnet/runtime/issues/55767 -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\tests\System.Runtime.Experimental.Tests.csproj" />
   </ItemGroup>

src/mono/wasm/build/README.md

@@ -49,3 +49,29 @@ The various task inputs correspond to properties as:
 This should be a step towards eventually having this build as a sdk.
 
 Refer to `WasmApp.targets` for more information about the properties/items used as inputs to the process.
+
+## Updating dependencies needed for building wasm apps
+
+For example, if the wasm targets are using a new task, then references to that
+need to be updated in a few places. Essentially, look for existing references
+to `MonoAOTCompiler`, or `WasmAppBuilder` in the relevant files, and duplicate
+them for the new task assembly.
+
+1. The task assembly dir, and its path need to be in two properties:
+    ```xml
+    <JsonToItemsTaskFactoryDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'JsonToItemsTaskFactory', 'Debug', '$(NetCoreAppToolCurrent)'))</JsonToItemsTaskFactoryDir>
+    <JsonToItemsTaskFactoryTasksAssemblyPath>$([MSBuild]::NormalizePath('$(JsonToItemsTaskFactoryDir)', 'JsonToItemsTaskFactory.dll'))</JsonToItemsTaskFactoryTasksAssemblyPath>
+    ```
+
+    And this needs to be set in:
+    - `Directory.Build.props`
+    - `src/mono/wasm/build/WasmApp.LocalBuild.props`
+    - `src/mono/wasm/build/WasmApp.LocalBuild.targets`
+    - `src/tests/Common/wasm-test-runner/WasmTestRunner.proj`
+
+2. The new dependency (eg. task assembly) needs to be sent to helix as a payload, see `src/libraries/sendtohelixhelp.proj`. Use `MonoAOTCompiler` as an example.
+
+3. Make changes similar to the one for existing dependent tasks in
+   - `eng/testing/linker/trimmingTests.targets`,
+   - `src/tests/Common/wasm-test-runner/WasmTestRunner.proj`
+   - `src/tests/Directory.Build.targets`

src/mono/wasm/build/WasmApp.InTree.targets

@@ -1,6 +1,7 @@
 <Project>
   <!-- This depends on the root Directory.Build.targets imported this file -->
   <UsingTask TaskName="MonoAOTCompiler" AssemblyFile="$(MonoAOTCompilerTasksAssemblyPath)" />
+  <UsingTask TaskName="RuntimeConfigParserTask" AssemblyFile="$(RuntimeConfigParserTasksAssemblyPath)" />
 
   <!-- TODO: this breaks runtime tests on Helix due to the file not being there for some reason. Once this is fixed we can remove the UpdateRuntimePack target here -->
   <!--<Import Project="$(RepositoryEngineeringDir)targetingpacks.targets" Condition="'$(TargetingpacksTargetsImported)' != 'true'"/>-->

src/mono/wasm/build/WasmApp.LocalBuild.props

@@ -35,6 +35,7 @@
     <WasmAppBuilderDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmAppBuilder', 'Debug', '$(_NetCoreAppToolCurrent)', 'publish'))</WasmAppBuilderDir>
     <WasmBuildTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'WasmBuildTasks', 'Debug', '$(_NetCoreAppToolCurrent)', 'publish'))</WasmBuildTasksDir>
     <MonoAOTCompilerDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'MonoAOTCompiler', 'Debug', '$(_NetCoreAppToolCurrent)'))</MonoAOTCompilerDir>
+    <RuntimeConfigParserDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'RuntimeConfigParser', 'Debug', '$(_NetCoreAppToolCurrent)'))</RuntimeConfigParserDir>
     <JsonToItemsTaskFactoryDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'JsonToItemsTaskFactory', 'Debug', '$(_NetCoreAppToolCurrent)'))</JsonToItemsTaskFactoryDir>
 
     <MonoArtifactsPath>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'mono', '$(TargetOS).$(TargetArchitecture).$(RuntimeConfig)'))</MonoArtifactsPath>
@@ -47,6 +48,7 @@
 
     <MicrosoftNetCoreAppRuntimePackLocationToUse>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'microsoft.netcore.app.runtime.browser-wasm'))</MicrosoftNetCoreAppRuntimePackLocationToUse>
     <MonoAOTCompilerDir>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'MonoAOTCompiler'))</MonoAOTCompilerDir>
+    <RuntimeConfigParserDir>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'RuntimeConfigParser'))</RuntimeConfigParserDir>
     <JsonToItemsTaskFactoryDir>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'JsonToItemsTaskFactory'))</JsonToItemsTaskFactoryDir>
     <WasmAppBuilderDir>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'WasmAppBuilder'))</WasmAppBuilderDir>
     <WasmBuildTasksDir>$([MSBuild]::NormalizeDirectory($(BuildBaseDir), 'WasmBuildTasks'))</WasmBuildTasksDir>
@@ -65,6 +67,7 @@
     <WasmAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmAppBuilderDir)', 'WasmAppBuilder.dll'))</WasmAppBuilderTasksAssemblyPath>
     <WasmBuildTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmBuildTasksDir)', 'WasmBuildTasks.dll'))</WasmBuildTasksAssemblyPath>
     <MonoAOTCompilerTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MonoAOTCompilerDir)', 'MonoAOTCompiler.dll'))</MonoAOTCompilerTasksAssemblyPath>
+    <RuntimeConfigParserTasksAssemblyPath>$([MSBuild]::NormalizePath('$(RuntimeConfigParserDir)', 'RuntimeConfigParser.dll'))</RuntimeConfigParserTasksAssemblyPath>
     <JsonToItemsTaskFactoryTasksAssemblyPath>$([MSBuild]::NormalizePath('$(JsonToItemsTaskFactoryDir)', 'JsonToItemsTaskFactory.dll'))</JsonToItemsTaskFactoryTasksAssemblyPath>
   </PropertyGroup>
 

src/mono/wasm/build/WasmApp.LocalBuild.targets

@@ -22,6 +22,7 @@
 <Project>
   <Import Project="$(MSBuildThisFileDirectory)WasmApp.targets" />
   <UsingTask TaskName="MonoAOTCompiler" AssemblyFile="$(MonoAOTCompilerTasksAssemblyPath)" />
+  <UsingTask TaskName="RuntimeConfigParserTask" AssemblyFile="$(RuntimeConfigParserTasksAssemblyPath)" />
 
   <PropertyGroup>
     <PublishTrimmed>true</PublishTrimmed>
@@ -64,6 +65,7 @@
       <WasmAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmAppBuilderDir)', 'WasmAppBuilder.dll'))</WasmAppBuilderTasksAssemblyPath>
       <WasmBuildTasksAssemblyPath>$([MSBuild]::NormalizePath('$(WasmBuildTasksDir)', 'WasmBuildTasks.dll'))</WasmBuildTasksAssemblyPath>
       <MonoAOTCompilerTasksAssemblyPath>$([MSBuild]::NormalizePath('$(MonoAOTCompilerDir)', 'MonoAOTCompiler.dll'))</MonoAOTCompilerTasksAssemblyPath>
+      <RuntimeConfigParserTasksAssemblyPath>$([MSBuild]::NormalizePath('$(RuntimeConfigParserDir)', 'RuntimeConfigParser.dll'))</RuntimeConfigParserTasksAssemblyPath>
       <JsonToItemsTaskFactoryTasksAssemblyPath>$([MSBuild]::NormalizePath('$(JsonToItemsTaskFactoryDir)', 'JsonToItemsTaskFactory.dll'))</JsonToItemsTaskFactoryTasksAssemblyPath>
     </PropertyGroup>
 

src/mono/wasm/build/WasmApp.targets

@@ -122,8 +122,15 @@
       <WasmMainAssemblyFileName Condition="'$(WasmMainAssemblyFileName)' == ''">$(TargetFileName)</WasmMainAssemblyFileName>
 
       <WasmAppDir>$([MSBuild]::NormalizeDirectory($(WasmAppDir)))</WasmAppDir>
+
+      <_MainAssemblyPath Condition="'%(WasmAssembliesToBundle.FileName)' == $(AssemblyName) and '%(WasmAssembliesToBundle.Extension)' == '.dll' and $(WasmGenerateAppBundle) == 'true'">%(WasmAssembliesToBundle.Identity)</_MainAssemblyPath>
+      <_WasmRuntimeConfigFilePath Condition="$(_MainAssemblyPath) != ''">$([System.IO.Path]::ChangeExtension($(_MainAssemblyPath), '.runtimeconfig.json'))</_WasmRuntimeConfigFilePath>
     </PropertyGroup>
 
+    <Warning Condition="'$(WasmGenerateAppBundle)' == 'true' and $(_MainAssemblyPath) == ''" Text="Could not find %24(AssemblyName)=$(AssemblyName) in the assemblies to be bundled.." />
+    <Warning Condition="'$(WasmGenerateAppBundle)' == 'true' and $(_WasmRuntimeConfigFilePath) != '' and !Exists($(_WasmRuntimeConfigFilePath))" 
+             Text="Could not find $(_WasmRuntimeConfigFilePath) for $(_MainAssemblyPath)." />
+
     <ItemGroup>
       <_WasmAssembliesInternal Include="@(WasmAssembliesToBundle->Distinct())" />
 
@@ -136,7 +143,29 @@
     </ItemGroup>
   </Target>
 
-  <Target Name="_WasmGenerateAppBundle" Condition="'$(WasmGenerateAppBundle)' == 'true'">
+  <Target Name="_WasmGenerateRuntimeConfig" Condition="Exists('$(_WasmRuntimeConfigFilePath)')">
+    <PropertyGroup>
+      <_ParsedRuntimeConfigFilePath>$([System.IO.Path]::GetDirectoryName($(_MainAssemblyPath)))\runtimeconfig.bin</_ParsedRuntimeConfigFilePath>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <_RuntimeConfigReservedProperties Include="RUNTIME_IDENTIFIER"/>
+      <_RuntimeConfigReservedProperties Include="APP_CONTEXT_BASE_DIRECTORY"/>
+    </ItemGroup>
+
+    <!-- Parse *.runtimeconfig.json file -->
+    <RuntimeConfigParserTask
+        RuntimeConfigFile="$(_WasmRuntimeConfigFilePath)"
+        OutputFile="$(_ParsedRuntimeConfigFilePath)"
+        RuntimeConfigReservedProperties="@(_RuntimeConfigReservedProperties)">
+    </RuntimeConfigParserTask>
+
+    <ItemGroup>
+      <WasmFilesToIncludeInFileSystem Include="$(_ParsedRuntimeConfigFilePath)" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_WasmGenerateAppBundle" Condition="'$(WasmGenerateAppBundle)' == 'true'" DependsOnTargets="_WasmGenerateRuntimeConfig">
     <Error Condition="'$(WasmMainJSPath)' == ''" Text="%24(WasmMainJSPath) property needs to be set" />
 
     <PropertyGroup>

src/mono/wasm/runtime/driver.c

@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <assert.h>
 #include <dlfcn.h>
+#include <sys/stat.h>
 
 #include <mono/metadata/assembly.h>
 #include <mono/metadata/tokentype.h>
@@ -92,6 +93,8 @@ void mono_trace_init (void);
 
 static MonoDomain *root_domain;
 
+#define RUNTIMECONFIG_BIN_FILE "runtimeconfig.bin"
+
 static MonoString*
 mono_wasm_invoke_js (MonoString *str, int *is_exception)
 {
@@ -476,6 +479,13 @@ mono_wasm_register_bundled_satellite_assemblies ()
 
 void mono_wasm_link_icu_shim (void);
 
+void
+cleanup_runtime_config (MonovmRuntimeConfigArguments *args, void *user_data)
+{
+	free (args);
+	free (user_data);
+}
+
 EMSCRIPTEN_KEEPALIVE void
 mono_wasm_load_runtime (const char *unused, int debug_level)
 {
@@ -493,7 +503,8 @@ mono_wasm_load_runtime (const char *unused, int debug_level)
     // corlib assemblies.
 	monoeg_g_setenv ("COMPlus_DebugWriteToStdErr", "1", 0);
 #endif
-
+	// When the list of app context properties changes, please update RuntimeConfigReservedProperties for
+	// target _WasmGenerateRuntimeConfig in WasmApp.targets file
 	const char *appctx_keys[2];
 	appctx_keys [0] = "APP_CONTEXT_BASE_DIRECTORY";
 	appctx_keys [1] = "RUNTIME_IDENTIFIER";
@@ -502,6 +513,23 @@ mono_wasm_load_runtime (const char *unused, int debug_level)
 	appctx_values [0] = "/";
 	appctx_values [1] = "browser-wasm";
 
+	char *file_name = RUNTIMECONFIG_BIN_FILE;
+	int str_len = strlen (file_name) + 1; // +1 is for the "/"
+	char *file_path = (char *)malloc (sizeof (char) * (str_len +1)); // +1 is for the terminating null character
+	int num_char = snprintf (file_path, (str_len + 1), "/%s", file_name);
+	struct stat buffer;
+
+	assert (num_char > 0 && num_char == str_len);
+
+	if (stat (file_path, &buffer) == 0) {
+		MonovmRuntimeConfigArguments *arg = (MonovmRuntimeConfigArguments *)malloc (sizeof (MonovmRuntimeConfigArguments));
+		arg->kind = 0;
+		arg->runtimeconfig.name.path = file_path;
+		monovm_runtimeconfig_initialize (arg, cleanup_runtime_config, file_path);
+	} else {
+		free (file_path);
+	}
+
 	monovm_initialize (2, appctx_keys, appctx_values);
 
 	mini_parse_debug_option ("top-runtime-invoke-unhandled");

src/tasks/AndroidAppBuilder/Templates/monodroid.c

@@ -234,13 +234,13 @@ mono_droid_runtime_init (const char* executable, int managed_argc, char* managed
     appctx_values[1] = bundle_path;
 
     char *file_name = RUNTIMECONFIG_BIN_FILE;
-    int str_len = strlen (bundle_path) + strlen (file_name) + 2;
-    char *file_path = (char *)malloc (sizeof (char) * str_len);
-    int num_char = snprintf (file_path, str_len, "%s/%s", bundle_path, file_name);
+    int str_len = strlen (bundle_path) + strlen (file_name) + 1; // +1 is for the "/"
+    char *file_path = (char *)malloc (sizeof (char) * (str_len +1)); // +1 is for the terminating null character
+    int num_char = snprintf (file_path, (str_len + 1), "%s/%s", bundle_path, file_name);
     struct stat buffer;
 
     LOG_INFO ("file_path: %s\n", file_path);
-    assert (num_char > 0 && num_char < str_len);
+    assert (num_char > 0 && num_char == str_len);
 
     if (stat (file_path, &buffer) == 0) {
         MonovmRuntimeConfigArguments *arg = (MonovmRuntimeConfigArguments *)malloc (sizeof (MonovmRuntimeConfigArguments));