Revert ".NET: Support hosted code interpreter for skill script execution (#4192)" (#4385)

This reverts commit c9cd067be6.

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillLoaderTests.cs

@@ -501,7 +501,7 @@ public sealed class FileAgentSkillLoaderTests : IDisposable
         }
 
         // Manually construct a skill that bypasses discovery validation
-        var frontmatter = new FileAgentSkillFrontmatter("symlink-read-skill", "A skill");
+        var frontmatter = new SkillFrontmatter("symlink-read-skill", "A skill");
         var skill = new FileAgentSkill(
             frontmatter: frontmatter,
             body: "See [doc](refs/data.md).",
@@ -532,54 +532,6 @@ public sealed class FileAgentSkillLoaderTests : IDisposable
         Assert.Equal("Body content.", skills["bom-skill"].Body);
     }
 
-    [Theory]
-    [InlineData("No resource references.", new string[0])]
-    [InlineData("Review `refs/FAQ.md` for details.", new[] { "refs/FAQ.md" })]
-    [InlineData("See [guide](refs/guide.md) then run `scripts/run.py`.", new[] { "refs/guide.md", "scripts/run.py" })]
-    public void DiscoverAndLoadSkills_ResourceReferences_ExtractsExpectedResourceNames(string body, string[] expectedResources)
-    {
-        // Arrange — create skill with resource files on disk so validation passes
-        string skillDir = Path.Combine(this._testRoot, "res-skill");
-        Directory.CreateDirectory(skillDir);
-        foreach (string resource in expectedResources)
-        {
-            string resourcePath = Path.Combine(skillDir, resource.Replace('/', Path.DirectorySeparatorChar));
-            Directory.CreateDirectory(Path.GetDirectoryName(resourcePath)!);
-            File.WriteAllText(resourcePath, "content");
-        }
-
-        File.WriteAllText(
-            Path.Combine(skillDir, "SKILL.md"),
-            $"---\nname: res-skill\ndescription: Resource test\n---\n{body}");
-
-        // Act
-        var skills = this._loader.DiscoverAndLoadSkills(new[] { this._testRoot });
-
-        // Assert
-        Assert.Single(skills);
-        var skill = skills["res-skill"];
-        Assert.Equal(expectedResources.Length, skill.ResourceNames.Count);
-        foreach (string expected in expectedResources)
-        {
-            Assert.Contains(expected, skill.ResourceNames);
-        }
-    }
-
-    [Fact]
-    public async Task ReadSkillResourceAsync_BacktickResourcePath_ReturnsContentAsync()
-    {
-        // Arrange — skill body uses backtick-quoted path
-        _ = this.CreateSkillDirectoryWithResource("backtick-read", "A skill", "Load `refs/doc.md` first.", "refs/doc.md", "Backtick content.");
-        var skills = this._loader.DiscoverAndLoadSkills(new[] { this._testRoot });
-        var skill = skills["backtick-read"];
-
-        // Act
-        string content = await this._loader.ReadSkillResourceAsync(skill, "refs/doc.md");
-
-        // Assert
-        Assert.Equal("Backtick content.", content);
-    }
-
     private string CreateSkillDirectory(string name, string description, string body)
     {
         string skillDir = Path.Combine(this._testRoot, name);

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillScriptExecutorTests.cs

@@ -1,170 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.Logging.Abstractions;
-
-namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
-
-/// <summary>
-/// Unit tests for <see cref="FileAgentSkillScriptExecutor"/> and its integration with <see cref="FileAgentSkillsProvider"/>.
-/// </summary>
-public sealed class FileAgentSkillScriptExecutorTests : IDisposable
-{
-    private readonly string _testRoot;
-    private readonly TestAIAgent _agent = new();
-    private static readonly FileAgentSkillScriptExecutionContext s_emptyContext = new(
-        new Dictionary<string, FileAgentSkill>(StringComparer.OrdinalIgnoreCase),
-        new FileAgentSkillLoader(NullLogger.Instance));
-
-    public FileAgentSkillScriptExecutorTests()
-    {
-        this._testRoot = Path.Combine(Path.GetTempPath(), "skill-executor-tests-" + Guid.NewGuid().ToString("N"));
-        Directory.CreateDirectory(this._testRoot);
-    }
-
-    public void Dispose()
-    {
-        if (Directory.Exists(this._testRoot))
-        {
-            Directory.Delete(this._testRoot, recursive: true);
-        }
-    }
-
-    [Fact]
-    public void HostedCodeInterpreter_ReturnsNonNullInstance()
-    {
-        // Act
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-
-        // Assert
-        Assert.NotNull(executor);
-    }
-
-    [Fact]
-    public void HostedCodeInterpreter_GetExecutionDetails_ReturnsNonNullInstructions()
-    {
-        // Arrange
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-
-        // Act
-        var details = executor.GetExecutionDetails(s_emptyContext);
-
-        // Assert
-        Assert.NotNull(details);
-        Assert.NotNull(details.Instructions);
-        Assert.NotEmpty(details.Instructions);
-    }
-
-    [Fact]
-    public void HostedCodeInterpreter_GetExecutionDetails_ReturnsNonEmptyToolsList()
-    {
-        // Arrange
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-
-        // Act
-        var details = executor.GetExecutionDetails(s_emptyContext);
-
-        // Assert
-        Assert.NotNull(details);
-        Assert.NotNull(details.Tools);
-        Assert.NotEmpty(details.Tools);
-    }
-
-    [Fact]
-    public async Task Provider_WithExecutor_IncludesExecutorInstructionsInPromptAsync()
-    {
-        // Arrange
-        CreateSkill(this._testRoot, "exec-skill", "Executor test", "Body.");
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-        var options = new FileAgentSkillsProviderOptions { ScriptExecutor = executor };
-        var provider = new FileAgentSkillsProvider(this._testRoot, options);
-        var invokingContext = new AIContextProvider.InvokingContext(this._agent, session: null, new AIContext());
-
-        // Act
-        var result = await provider.InvokingAsync(invokingContext, CancellationToken.None);
-
-        // Assert — executor instructions should be merged into the prompt
-        Assert.NotNull(result.Instructions);
-        Assert.Contains("code interpreter", result.Instructions, StringComparison.OrdinalIgnoreCase);
-    }
-
-    [Fact]
-    public async Task Provider_WithExecutor_IncludesExecutorToolsAsync()
-    {
-        // Arrange
-        CreateSkill(this._testRoot, "tools-exec-skill", "Executor tools test", "Body.");
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-        var options = new FileAgentSkillsProviderOptions { ScriptExecutor = executor };
-        var provider = new FileAgentSkillsProvider(this._testRoot, options);
-        var invokingContext = new AIContextProvider.InvokingContext(this._agent, session: null, new AIContext());
-
-        // Act
-        var result = await provider.InvokingAsync(invokingContext, CancellationToken.None);
-
-        // Assert — should have 3 tools: load_skill, read_skill_resource, and HostedCodeInterpreterTool
-        Assert.NotNull(result.Tools);
-        Assert.Equal(3, result.Tools!.Count());
-        var toolNames = result.Tools!.Select(t => t.Name).ToList();
-        Assert.Contains("load_skill", toolNames);
-        Assert.Contains("read_skill_resource", toolNames);
-        Assert.Single(result.Tools!, t => t is HostedCodeInterpreterTool);
-    }
-
-    [Fact]
-    public async Task Provider_WithoutExecutor_DoesNotIncludeExecutorToolsAsync()
-    {
-        // Arrange
-        CreateSkill(this._testRoot, "no-exec-skill", "No executor test", "Body.");
-        var provider = new FileAgentSkillsProvider(this._testRoot);
-        var invokingContext = new AIContextProvider.InvokingContext(this._agent, session: null, new AIContext());
-
-        // Act
-        var result = await provider.InvokingAsync(invokingContext, CancellationToken.None);
-
-        // Assert — should only have the two base tools
-        Assert.NotNull(result.Tools);
-        Assert.Equal(2, result.Tools!.Count());
-    }
-
-    [Fact]
-    public async Task Provider_WithHostedCodeInterpreter_MergesScriptInstructionsIntoPromptAsync()
-    {
-        // Arrange
-        CreateSkill(this._testRoot, "merge-skill", "Merge test", "Body.");
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-        var options = new FileAgentSkillsProviderOptions { ScriptExecutor = executor };
-        var provider = new FileAgentSkillsProvider(this._testRoot, options);
-        var invokingContext = new AIContextProvider.InvokingContext(this._agent, session: null, new AIContext());
-
-        // Act
-        var result = await provider.InvokingAsync(invokingContext, CancellationToken.None);
-
-        // Assert — prompt should contain both the skill listing and the executor's script instructions
-        Assert.NotNull(result.Instructions);
-        string instructions = result.Instructions!;
-
-        // Skill listing is present
-        Assert.Contains("merge-skill", instructions);
-        Assert.Contains("Merge test", instructions);
-
-        // Hosted code interpreter script instructions are merged into the prompt
-        Assert.Contains("executable scripts", instructions);
-        Assert.Contains("read_skill_resource", instructions);
-        Assert.Contains("Execute the script using the code interpreter", instructions);
-    }
-
-    private static void CreateSkill(string root, string name, string description, string body)
-    {
-        string skillDir = Path.Combine(root, name);
-        Directory.CreateDirectory(skillDir);
-        File.WriteAllText(
-            Path.Combine(skillDir, "SKILL.md"),
-            $"---\nname: {name}\ndescription: {description}\n---\n{body}");
-    }
-}

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillsProviderTests.cs

@@ -96,7 +96,7 @@ public sealed class FileAgentSkillsProviderTests : IDisposable
         this.CreateSkill("custom-prompt-skill", "Custom prompt", "Body.");
         var options = new FileAgentSkillsProviderOptions
         {
-            SkillsInstructionPrompt = "Custom template: {skills}"
+            SkillsInstructionPrompt = "Custom template: {0}"
         };
         var provider = new FileAgentSkillsProvider(this._testRoot, options);
         var inputContext = new AIContext();
@@ -110,6 +110,21 @@ public sealed class FileAgentSkillsProviderTests : IDisposable
         Assert.StartsWith("Custom template:", result.Instructions);
     }
 
+    [Fact]
+    public void Constructor_InvalidPromptTemplate_ThrowsArgumentException()
+    {
+        // Arrange — template with unescaped braces and no valid {0} placeholder
+        var options = new FileAgentSkillsProviderOptions
+        {
+            SkillsInstructionPrompt = "Bad template with {unescaped} braces"
+        };
+
+        // Act & Assert
+        var ex = Assert.Throws<ArgumentException>(() => new FileAgentSkillsProvider(this._testRoot, options));
+        Assert.Contains("SkillsInstructionPrompt", ex.Message);
+        Assert.Equal("options", ex.ParamName);
+    }
+
     [Fact]
     public async Task InvokingCoreAsync_SkillNamesAreXmlEscapedAsync()
     {

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/HostedCodeInterpreterFileAgentSkillScriptExecutorTests.cs

@@ -1,72 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Collections.Generic;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.Logging.Abstractions;
-
-namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
-
-/// <summary>
-/// Unit tests for <see cref="HostedCodeInterpreterFileAgentSkillScriptExecutor"/>.
-/// </summary>
-public sealed class HostedCodeInterpreterFileAgentSkillScriptExecutorTests
-{
-    private static readonly FileAgentSkillScriptExecutionContext s_emptyContext = new(
-        new Dictionary<string, FileAgentSkill>(StringComparer.OrdinalIgnoreCase),
-        new FileAgentSkillLoader(NullLogger.Instance));
-
-    [Fact]
-    public void GetExecutionDetails_ReturnsScriptExecutionGuidance()
-    {
-        // Arrange
-        var executor = new HostedCodeInterpreterFileAgentSkillScriptExecutor();
-
-        // Act
-        var details = executor.GetExecutionDetails(s_emptyContext);
-
-        // Assert
-        Assert.NotNull(details.Instructions);
-        Assert.Contains("read_skill_resource", details.Instructions);
-        Assert.Contains("code interpreter", details.Instructions);
-    }
-
-    [Fact]
-    public void GetExecutionDetails_ReturnsSingleHostedCodeInterpreterTool()
-    {
-        // Arrange
-        var executor = new HostedCodeInterpreterFileAgentSkillScriptExecutor();
-
-        // Act
-        var details = executor.GetExecutionDetails(s_emptyContext);
-
-        // Assert
-        Assert.NotNull(details.Tools);
-        Assert.Single(details.Tools!);
-        Assert.IsType<HostedCodeInterpreterTool>(details.Tools![0]);
-    }
-
-    [Fact]
-    public void GetExecutionDetails_ReturnsSameInstanceOnMultipleCalls()
-    {
-        // Arrange
-        var executor = new HostedCodeInterpreterFileAgentSkillScriptExecutor();
-
-        // Act
-        var details1 = executor.GetExecutionDetails(s_emptyContext);
-        var details2 = executor.GetExecutionDetails(s_emptyContext);
-
-        // Assert — static details should be reused
-        Assert.Same(details1, details2);
-    }
-
-    [Fact]
-    public void FactoryMethod_ReturnsHostedCodeInterpreterFileAgentSkillScriptExecutor()
-    {
-        // Act
-        var executor = FileAgentSkillScriptExecutor.HostedCodeInterpreter();
-
-        // Assert
-        Assert.IsType<HostedCodeInterpreterFileAgentSkillScriptExecutor>(executor);
-    }
-}