Reverting "Removing MultiLanguage feature flag (#8727)" (#9079)

Author: soninaren

src/WebJobs.Script/Environment/EnvironmentExtensions.cs

@@ -364,7 +364,7 @@ public static bool IsMultiLanguageRuntimeEnvironment(this IEnvironment environme
         {
             if (!isMultiLanguageEnabled.HasValue)
             {
-                isMultiLanguageEnabled = environment.IsLogicApp();
+                isMultiLanguageEnabled = environment.IsLogicApp() && FeatureFlags.IsEnabled(ScriptConstants.FeatureFlagEnableMultiLanguageWorker, environment);
             }
             return isMultiLanguageEnabled.Value;
         }

src/WebJobs.Script/ScriptConstants.cs

@@ -122,6 +122,7 @@ public static class ScriptConstants
         public const string FeatureFlagDisableMergedWebHostScriptHostConfiguration = "DisableMergedConfiguration";
         public const string FeatureFlagDisableWorkerIndexing = "DisableWorkerIndexing";
         public const string FeatureFlagEnableDebugTracing = "EnableDebugTracing";
+        public const string FeatureFlagEnableMultiLanguageWorker = "EnableMultiLanguageWorker";
         public const string FeatureFlagEnableProxies = "EnableProxies";
         public const string FeatureFlagEnableLinuxEPExecutionCount = "EnableLinuxFEC";
 

test/WebJobs.Script.Tests.Integration/WebHostEndToEnd/MultiLanguageEndToEndTests.cs

@@ -39,6 +39,7 @@ public async Task CodelessFunction_CanUse_MultipleLanguageProviders()
             var settings = new Dictionary<string, string>()
             {
                 [EnvironmentSettingNames.AppKind] = "workflowApp",
+                [EnvironmentSettingNames.AzureWebJobsFeatureFlags] = $"{ScriptConstants.FeatureFlagEnableMultiLanguageWorker}",
             };
             var testEnvironment = new TestEnvironment(settings);
 
@@ -85,6 +86,7 @@ public async Task CodelessFunction_CanUse_SingleJavaLanguageProviders()
             var settings = new Dictionary<string, string>()
             {
                 [EnvironmentSettingNames.AppKind] = "workflowApp",
+                [EnvironmentSettingNames.AzureWebJobsFeatureFlags] = $"{ScriptConstants.FeatureFlagEnableMultiLanguageWorker}",
             };
             var testEnvironment = new TestEnvironment(settings);
 
@@ -124,6 +126,7 @@ public async Task CodelessFunction_CanUse_SingleJavascriptLanguageProviders()
             var settings = new Dictionary<string, string>()
             {
                 [EnvironmentSettingNames.AppKind] = "workflowApp",
+                [EnvironmentSettingNames.AzureWebJobsFeatureFlags] = $"{ScriptConstants.FeatureFlagEnableMultiLanguageWorker}",
             };
             var testEnvironment = new TestEnvironment(settings);
 
@@ -163,6 +166,7 @@ public async Task CodelessFunction_CanUse_NoLanguageProviders()
             var settings = new Dictionary<string, string>()
             {
                 [EnvironmentSettingNames.AppKind] = "workflowApp",
+                [EnvironmentSettingNames.AzureWebJobsFeatureFlags] = $"{ScriptConstants.FeatureFlagEnableMultiLanguageWorker}",
             };
             var testEnvironment = new TestEnvironment(settings);