Add file commands for save-state and set-output (#2118)

src/Runner.Common/ExtensionManager.cs

@@ -60,6 +60,8 @@ namespace GitHub.Runner.Common
                     Add<T>(extensions, "GitHub.Runner.Worker.AddPathFileCommand, Runner.Worker");
                     Add<T>(extensions, "GitHub.Runner.Worker.SetEnvFileCommand, Runner.Worker");
                     Add<T>(extensions, "GitHub.Runner.Worker.CreateStepSummaryCommand, Runner.Worker");
+                    Add<T>(extensions, "GitHub.Runner.Worker.SaveStateFileCommand, Runner.Worker");
+                    Add<T>(extensions, "GitHub.Runner.Worker.SetOutputFileCommand, Runner.Worker");
                     break;
                 case "GitHub.Runner.Listener.Check.ICheckExtension":
                     Add<T>(extensions, "GitHub.Runner.Listener.Check.InternetCheck, Runner.Listener");

src/Runner.Worker/FileCommandManager.cs

@@ -138,74 +138,10 @@ namespace GitHub.Runner.Worker
 
         public void ProcessCommand(IExecutionContext context, string filePath, ContainerInfo container)
         {
-            try
+            var pairs = new EnvFileKeyValuePairs(context, filePath);
+            foreach (var pair in pairs)
             {
-                var text = File.ReadAllText(filePath) ?? string.Empty;
+                SetEnvironmentVariable(context, pair.Key, pair.Value);
-                var index = 0;
-                var line = ReadLine(text, ref index);
-                while (line != null)
-                {
-                    if (!string.IsNullOrEmpty(line))
-                    {
-                        var equalsIndex = line.IndexOf("=", StringComparison.Ordinal);
-                        var heredocIndex = line.IndexOf("<<", StringComparison.Ordinal);
-
-                        // Normal style NAME=VALUE
-                        if (equalsIndex >= 0 && (heredocIndex < 0 || equalsIndex < heredocIndex))
-                        {
-                            var split = line.Split(new[] { '=' }, 2, StringSplitOptions.None);
-                            if (string.IsNullOrEmpty(line))
-                            {
-                                throw new Exception($"Invalid environment variable format '{line}'. Environment variable name must not be empty");
-                            }
-                            SetEnvironmentVariable(context, split[0], split[1]);
-                        }
-                        // Heredoc style NAME<<EOF
-                        else if (heredocIndex >= 0 && (equalsIndex < 0 || heredocIndex < equalsIndex))
-                        {
-                            var split = line.Split(new[] { "<<" }, 2, StringSplitOptions.None);
-                            if (string.IsNullOrEmpty(split[0]) || string.IsNullOrEmpty(split[1]))
-                            {
-                                throw new Exception($"Invalid environment variable format '{line}'. Environment variable name must not be empty and delimiter must not be empty");
-                            }
-                            var name = split[0];
-                            var delimiter = split[1];
-                            var startIndex = index; // Start index of the value (inclusive)
-                            var endIndex = index;   // End index of the value (exclusive)
-                            var tempLine = ReadLine(text, ref index, out var newline);
-                            while (!string.Equals(tempLine, delimiter, StringComparison.Ordinal))
-                            {
-                                if (tempLine == null)
-                                {
-                                    throw new Exception($"Invalid environment variable value. Matching delimiter not found '{delimiter}'");
-                                }
-                                if (newline == null)
-                                {
-                                    throw new Exception($"Invalid environment variable value. EOF marker missing new line.");
-                                }
-                                endIndex = index - newline.Length;
-                                tempLine = ReadLine(text, ref index, out newline);
-                            }
-
-                            var value = endIndex > startIndex ? text.Substring(startIndex, endIndex - startIndex) : string.Empty;
-                            SetEnvironmentVariable(context, name, value);
-                        }
-                        else
-                        {
-                            throw new Exception($"Invalid environment variable format '{line}'");
-                        }
-                    }
-
-                    line = ReadLine(text, ref index);
-                }
-            }
-            catch (DirectoryNotFoundException)
-            {
-                context.Debug($"Environment variables file does not exist '{filePath}'");
-            }
-            catch (FileNotFoundException)
-            {
-                context.Debug($"Environment variables file does not exist '{filePath}'");
             }
         }
 
@@ -218,48 +154,6 @@ namespace GitHub.Runner.Worker
             context.SetEnvContext(name, value);
             context.Debug($"{name}='{value}'");
         }
-
-        private static string ReadLine(
-            string text,
-            ref int index)
-        {
-            return ReadLine(text, ref index, out _);
-        }
-
-        private static string ReadLine(
-            string text,
-            ref int index,
-            out string newline)
-        {
-            if (index >= text.Length)
-            {
-                newline = null;
-                return null;
-            }
-
-            var originalIndex = index;
-            var lfIndex = text.IndexOf("\n", index, StringComparison.Ordinal);
-            if (lfIndex < 0)
-            {
-                index = text.Length;
-                newline = null;
-                return text.Substring(originalIndex);
-            }
-
-#if OS_WINDOWS
-            var crLFIndex = text.IndexOf("\r\n", index, StringComparison.Ordinal);
-            if (crLFIndex >= 0 && crLFIndex < lfIndex)
-            {
-                index = crLFIndex + 2; // Skip over CRLF
-                newline = "\r\n";
-                return text.Substring(originalIndex, crLFIndex - originalIndex);
-            }
-#endif
-
-            index = lfIndex + 1; // Skip over LF
-            newline = "\n";
-            return text.Substring(originalIndex, lfIndex - originalIndex);
-        }
     }
 
     public sealed class CreateStepSummaryCommand : RunnerService, IFileCommandExtension
@@ -325,4 +219,200 @@ namespace GitHub.Runner.Worker
             }
         }
     }
+
+    public sealed class SaveStateFileCommand : RunnerService, IFileCommandExtension
+    {
+        public string ContextName => "state";
+        public string FilePrefix => "save_state_";
+
+        public Type ExtensionType => typeof(IFileCommandExtension);
+
+        public void ProcessCommand(IExecutionContext context, string filePath, ContainerInfo container)
+        {
+            var pairs = new EnvFileKeyValuePairs(context, filePath);
+            foreach (var pair in pairs)
+            {
+                // Embedded steps (composite) keep track of the state at the root level
+                if (context.IsEmbedded)
+                {
+                    var id = context.EmbeddedId;
+                    if (!context.Root.EmbeddedIntraActionState.ContainsKey(id))
+                    {
+                        context.Root.EmbeddedIntraActionState[id] = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+                    }
+                    context.Root.EmbeddedIntraActionState[id][pair.Key] = pair.Value;
+                }
+                // Otherwise modify the ExecutionContext
+                else
+                {
+                    context.IntraActionState[pair.Key] = pair.Value;
+                }
+
+                context.Debug($"Save intra-action state {pair.Key} = {pair.Value}");
+            }
+        }
+    }
+
+    public sealed class SetOutputFileCommand : RunnerService, IFileCommandExtension
+    {
+        public string ContextName => "output";
+        public string FilePrefix => "set_output_";
+
+        public Type ExtensionType => typeof(IFileCommandExtension);
+
+        public void ProcessCommand(IExecutionContext context, string filePath, ContainerInfo container)
+        {
+            var pairs = new EnvFileKeyValuePairs(context, filePath);
+            foreach (var pair in pairs)
+            {
+                context.SetOutput(pair.Key, pair.Value, out var reference);
+                context.Debug($"Set output {pair.Key} = {pair.Value}");
+            }
+        }
+    }
+
+    public sealed class EnvFileKeyValuePairs: IEnumerable<KeyValuePair<string, string>>
+    {
+        private IExecutionContext _context;
+        private string _filePath;
+
+        public EnvFileKeyValuePairs(IExecutionContext context, string filePath)
+        {
+            _context = context;
+            _filePath = filePath;
+        }
+
+        public IEnumerator<KeyValuePair<string, string>> GetEnumerator()
+        {
+            var text = string.Empty;
+            try
+            {
+                text = File.ReadAllText(_filePath) ?? string.Empty;
+            }
+            catch (DirectoryNotFoundException)
+            {
+                _context.Debug($"File does not exist '{_filePath}'");
+                yield break;
+            }
+            catch (FileNotFoundException)
+            {
+                _context.Debug($"File does not exist '{_filePath}'");
+                yield break;
+            }
+
+            var index = 0;
+            var line = ReadLine(text, ref index);
+            while (line != null)
+            {
+                if (!string.IsNullOrEmpty(line))
+                {
+                    var key = string.Empty;
+                    var output = string.Empty;
+
+                    var equalsIndex = line.IndexOf("=", StringComparison.Ordinal);
+                    var heredocIndex = line.IndexOf("<<", StringComparison.Ordinal);
+
+                    // Normal style NAME=VALUE
+                    if (equalsIndex >= 0 && (heredocIndex < 0 || equalsIndex < heredocIndex))
+                    {
+                        var split = line.Split(new[] { '=' }, 2, StringSplitOptions.None);
+                        if (string.IsNullOrEmpty(line))
+                        {
+                            throw new Exception($"Invalid format '{line}'. Name must not be empty");
+                        }
+
+                        key = split[0];
+                        output = split[1];
+                    }
+
+                    // Heredoc style NAME<<EOF
+                    else if (heredocIndex >= 0 && (equalsIndex < 0 || heredocIndex < equalsIndex))
+                    {
+                        var split = line.Split(new[] { "<<" }, 2, StringSplitOptions.None);
+                        if (string.IsNullOrEmpty(split[0]) || string.IsNullOrEmpty(split[1]))
+                        {
+                            throw new Exception($"Invalid format '{line}'. Name must not be empty and delimiter must not be empty");
+                        }
+                        key = split[0];
+                        var delimiter = split[1];
+                        var startIndex = index; // Start index of the value (inclusive)
+                        var endIndex = index;   // End index of the value (exclusive)
+                        var tempLine = ReadLine(text, ref index, out var newline);
+                        while (!string.Equals(tempLine, delimiter, StringComparison.Ordinal))
+                        {
+                            if (tempLine == null)
+                            {
+                                throw new Exception($"Invalid value. Matching delimiter not found '{delimiter}'");
+                            }
+                            if (newline == null)
+                            {
+                                throw new Exception($"Invalid value. EOF marker missing new line.");
+                            }
+                            endIndex = index - newline.Length;
+                            tempLine = ReadLine(text, ref index, out newline);
+                        }
+
+                        output = endIndex > startIndex ? text.Substring(startIndex, endIndex - startIndex) : string.Empty;
+                    }
+                    else
+                    {
+                        throw new Exception($"Invalid format '{line}'");
+                    }
+
+                    yield return new KeyValuePair<string, string>(key, output);
+                }
+
+                line = ReadLine(text, ref index);
+            }
+        }
+
+        System.Collections.IEnumerator
+            System.Collections.IEnumerable.GetEnumerator()
+        {
+            // Invoke IEnumerator<KeyValuePair<string, string>> GetEnumerator() above.
+            return GetEnumerator();
+        }
+
+        private static string ReadLine(
+                string text,
+                ref int index)
+        {
+            return ReadLine(text, ref index, out _);
+        }
+
+        private static string ReadLine(
+                string text,
+                ref int index,
+                out string newline)
+        {
+            if (index >= text.Length)
+            {
+                newline = null;
+                return null;
+            }
+
+            var originalIndex = index;
+            var lfIndex = text.IndexOf("\n", index, StringComparison.Ordinal);
+            if (lfIndex < 0)
+            {
+                index = text.Length;
+                newline = null;
+                return text.Substring(originalIndex);
+            }
+
+#if OS_WINDOWS
+            var crLFIndex = text.IndexOf("\r\n", index, StringComparison.Ordinal);
+            if (crLFIndex >= 0 && crLFIndex < lfIndex)
+            {
+                index = crLFIndex + 2; // Skip over CRLF
+                newline = "\r\n";
+                return text.Substring(originalIndex, crLFIndex - originalIndex);
+            }
+#endif
+
+            index = lfIndex + 1; // Skip over LF
+            newline = "\n";
+            return text.Substring(originalIndex, lfIndex - originalIndex);
+        }
+    }
 }

src/Runner.Worker/GitHubContext.cs

@@ -21,6 +21,7 @@ namespace GitHub.Runner.Worker
             "graphql_url",
             "head_ref",
             "job",
+            "output",
             "path",
             "ref_name",
             "ref_protected",
@@ -34,6 +35,7 @@ namespace GitHub.Runner.Worker
             "run_number",
             "server_url",
             "sha",
+            "state",
             "step_summary",
             "triggering_actor",
             "workflow",

src/Test/L0/Worker/SaveStateFileCommandL0.cs

@@ -0,0 +1,438 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Runtime.CompilerServices;
+using GitHub.Runner.Common.Util;
+using GitHub.Runner.Sdk;
+using GitHub.Runner.Worker;
+using GitHub.Runner.Worker.Container;
+using GitHub.Runner.Worker.Handlers;
+using Moq;
+using Xunit;
+using DTWebApi = GitHub.DistributedTask.WebApi;
+
+namespace GitHub.Runner.Common.Tests.Worker
+{
+    public sealed class SaveStateFileCommandL0
+    {
+        private Mock<IExecutionContext> _executionContext;
+        private List<Tuple<DTWebApi.Issue, string>> _issues;
+        private string _rootDirectory;
+        private SaveStateFileCommand _saveStateFileCommand;
+        private Dictionary<string, string> _intraActionState;
+        private ITraceWriter _trace;
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_DirectoryNotFound()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "directory-not-found", "env");
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _intraActionState.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_NotFound()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "file-not-found");
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _intraActionState.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_EmptyFile()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "empty-file");
+                var content = new List<string>();
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _intraActionState.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Simple()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_STATE=MY VALUE",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _intraActionState.Count);
+                Assert.Equal("MY VALUE", _intraActionState["MY_STATE"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Simple_SkipEmptyLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    string.Empty,
+                    "MY_STATE=my value",
+                    string.Empty,
+                    "MY_STATE_2=my second value",
+                    string.Empty,
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(2, _intraActionState.Count);
+                Assert.Equal("my value", _intraActionState["MY_STATE"]);
+                Assert.Equal("my second value", _intraActionState["MY_STATE_2"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Simple_EmptyValue()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple-empty-value");
+                var content = new List<string>
+                {
+                    "MY_STATE=",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _intraActionState.Count);
+                Assert.Equal(string.Empty, _intraActionState["MY_STATE"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Simple_MultipleValues()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_STATE=my value",
+                    "MY_STATE_2=",
+                    "MY_STATE_3=my third value",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(3, _intraActionState.Count);
+                Assert.Equal("my value", _intraActionState["MY_STATE"]);
+                Assert.Equal(string.Empty, _intraActionState["MY_STATE_2"]);
+                Assert.Equal("my third value", _intraActionState["MY_STATE_3"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Simple_SpecialCharacters()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_STATE==abc",
+                    "MY_STATE_2=def=ghi",
+                    "MY_STATE_3=jkl=",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(3, _intraActionState.Count);
+                Assert.Equal("=abc", _intraActionState["MY_STATE"]);
+                Assert.Equal("def=ghi", _intraActionState["MY_STATE_2"]);
+                Assert.Equal("jkl=", _intraActionState["MY_STATE_3"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<EOF",
+                    "line one",
+                    "line two",
+                    "line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _intraActionState.Count);
+                Assert.Equal($"line one{Environment.NewLine}line two{Environment.NewLine}line three", _intraActionState["MY_STATE"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_EmptyValue()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<EOF",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _intraActionState.Count);
+                Assert.Equal(string.Empty, _intraActionState["MY_STATE"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_SkipEmptyLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    string.Empty,
+                    "MY_STATE<<EOF",
+                    "hello",
+                    "world",
+                    "EOF",
+                    string.Empty,
+                    "MY_STATE_2<<EOF",
+                    "HELLO",
+                    "AGAIN",
+                    "EOF",
+                    string.Empty,
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(2, _intraActionState.Count);
+                Assert.Equal($"hello{Environment.NewLine}world", _intraActionState["MY_STATE"]);
+                Assert.Equal($"HELLO{Environment.NewLine}AGAIN", _intraActionState["MY_STATE_2"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_SpecialCharacters()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<=EOF",
+                    "hello",
+                    "one",
+                    "=EOF",
+                    "MY_STATE_2<<<EOF",
+                    "hello",
+                    "two",
+                    "<EOF",
+                    "MY_STATE_3<<EOF",
+                    "hello",
+                    string.Empty,
+                    "three",
+                    string.Empty,
+                    "EOF",
+                    "MY_STATE_4<<EOF",
+                    "hello=four",
+                    "EOF",
+                    "MY_STATE_5<<EOF",
+                    " EOF",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(5, _intraActionState.Count);
+                Assert.Equal($"hello{Environment.NewLine}one", _intraActionState["MY_STATE"]);
+                Assert.Equal($"hello{Environment.NewLine}two", _intraActionState["MY_STATE_2"]);
+                Assert.Equal($"hello{Environment.NewLine}{Environment.NewLine}three{Environment.NewLine}", _intraActionState["MY_STATE_3"]);
+                Assert.Equal($"hello=four", _intraActionState["MY_STATE_4"]);
+                Assert.Equal($" EOF", _intraActionState["MY_STATE_5"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_MissingNewLine()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<EOF",
+                    "line one",
+                    "line two",
+                    "line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, " ");
+                var ex = Assert.Throws<Exception>(() => _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null));
+                Assert.Contains("Matching delimiter not found", ex.Message);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_MissingNewLineMultipleLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<EOF",
+                    @"line one
+                    line two
+                    line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, " ");
+                var ex = Assert.Throws<Exception>(() => _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null));
+                Assert.Contains("EOF marker missing new line", ex.Message);
+            }
+        }
+
+#if OS_WINDOWS
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateFileCommand_Heredoc_PreservesNewline()
+        {
+            using (var hostContext = Setup())
+            {
+                var newline = "\n";
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_STATE<<EOF",
+                    "hello",
+                    "world",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, newline: newline);
+                _saveStateFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _intraActionState.Count);
+                Assert.Equal($"hello{newline}world", _intraActionState["MY_STATE"]);
+            }
+        }
+#endif
+
+        private void WriteContent(
+            string path,
+            List<string> content,
+            string newline = null)
+        {
+            if (string.IsNullOrEmpty(newline))
+            {
+                newline = Environment.NewLine;
+            }
+
+            var encoding = new UTF8Encoding(true); // Emit BOM
+            var contentStr = string.Join(newline, content);
+            File.WriteAllText(path, contentStr, encoding);
+        }
+
+        private TestHostContext Setup([CallerMemberName] string name = "")
+        {
+            _issues = new List<Tuple<DTWebApi.Issue, string>>();
+            _intraActionState = new Dictionary<string, string>();
+
+            var hostContext = new TestHostContext(this, name);
+
+            // Trace
+            _trace = hostContext.GetTrace();
+
+            // Directory for test data
+            var workDirectory = hostContext.GetDirectory(WellKnownDirectory.Work);
+            ArgUtil.NotNullOrEmpty(workDirectory, nameof(workDirectory));
+            Directory.CreateDirectory(workDirectory);
+            _rootDirectory = Path.Combine(workDirectory, nameof(SaveStateFileCommandL0));
+            Directory.CreateDirectory(_rootDirectory);
+
+            // Execution context
+            _executionContext = new Mock<IExecutionContext>();
+            _executionContext.Setup(x => x.Global)
+                .Returns(new GlobalContext
+                {
+                    EnvironmentVariables = new Dictionary<string, string>(VarUtil.EnvironmentVariableKeyComparer),
+                    WriteDebug = true,
+                });
+            _executionContext.Setup(x => x.AddIssue(It.IsAny<DTWebApi.Issue>(), It.IsAny<string>()))
+                .Callback((DTWebApi.Issue issue, string logMessage) =>
+                {
+                    _issues.Add(new Tuple<DTWebApi.Issue, string>(issue, logMessage));
+                    var message = !string.IsNullOrEmpty(logMessage) ? logMessage : issue.Message;
+                    _trace.Info($"Issue '{issue.Type}': {message}");
+                });
+            _executionContext.Setup(x => x.Write(It.IsAny<string>(), It.IsAny<string>()))
+                .Callback((string tag, string message) =>
+                {
+                    _trace.Info($"{tag}{message}");
+                });
+            _executionContext.Setup(x => x.IntraActionState)
+              .Returns(_intraActionState);
+
+            // SaveStateFileCommand
+            _saveStateFileCommand = new SaveStateFileCommand();
+            _saveStateFileCommand.Initialize(hostContext);
+
+            return hostContext;
+        }
+    }
+}

src/Test/L0/Worker/SetOutputFileCommandL0.cs

@@ -0,0 +1,444 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Runtime.CompilerServices;
+using GitHub.Runner.Common.Util;
+using GitHub.Runner.Sdk;
+using GitHub.Runner.Worker;
+using GitHub.Runner.Worker.Container;
+using GitHub.Runner.Worker.Handlers;
+using Moq;
+using Xunit;
+using DTWebApi = GitHub.DistributedTask.WebApi;
+
+namespace GitHub.Runner.Common.Tests.Worker
+{
+    public sealed class SetOutputFileCommandL0
+    {
+        private Mock<IExecutionContext> _executionContext;
+        private List<Tuple<DTWebApi.Issue, string>> _issues;
+        private Dictionary<string, string> _outputs;
+        private string _rootDirectory;
+        private SetOutputFileCommand _setOutputFileCommand;
+        private ITraceWriter _trace;
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_DirectoryNotFound()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "directory-not-found", "env");
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _outputs.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_NotFound()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "file-not-found");
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _outputs.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_EmptyFile()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "empty-file");
+                var content = new List<string>();
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(0, _outputs.Count);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Simple()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT=MY VALUE",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _outputs.Count);
+                Assert.Equal("MY VALUE", _outputs["MY_OUTPUT"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Simple_SkipEmptyLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    string.Empty,
+                    "MY_OUTPUT=my value",
+                    string.Empty,
+                    "MY_OUTPUT_2=my second value",
+                    string.Empty,
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(2, _outputs.Count);
+                Assert.Equal("my value", _outputs["MY_OUTPUT"]);
+                Assert.Equal("my second value", _outputs["MY_OUTPUT_2"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Simple_EmptyValue()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple-empty-value");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT=",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _outputs.Count);
+                Assert.Equal(string.Empty, _outputs["MY_OUTPUT"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Simple_MultipleValues()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT=my value",
+                    "MY_OUTPUT_2=",
+                    "MY_OUTPUT_3=my third value",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(3, _outputs.Count);
+                Assert.Equal("my value", _outputs["MY_OUTPUT"]);
+                Assert.Equal(string.Empty, _outputs["MY_OUTPUT_2"]);
+                Assert.Equal("my third value", _outputs["MY_OUTPUT_3"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Simple_SpecialCharacters()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "simple");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT==abc",
+                    "MY_OUTPUT_2=def=ghi",
+                    "MY_OUTPUT_3=jkl=",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(3, _outputs.Count);
+                Assert.Equal("=abc", _outputs["MY_OUTPUT"]);
+                Assert.Equal("def=ghi", _outputs["MY_OUTPUT_2"]);
+                Assert.Equal("jkl=", _outputs["MY_OUTPUT_3"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<EOF",
+                    "line one",
+                    "line two",
+                    "line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _outputs.Count);
+                Assert.Equal($"line one{Environment.NewLine}line two{Environment.NewLine}line three", _outputs["MY_OUTPUT"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_EmptyValue()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<EOF",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _outputs.Count);
+                Assert.Equal(string.Empty, _outputs["MY_OUTPUT"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_SkipEmptyLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    string.Empty,
+                    "MY_OUTPUT<<EOF",
+                    "hello",
+                    "world",
+                    "EOF",
+                    string.Empty,
+                    "MY_OUTPUT_2<<EOF",
+                    "HELLO",
+                    "AGAIN",
+                    "EOF",
+                    string.Empty,
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(2, _outputs.Count);
+                Assert.Equal($"hello{Environment.NewLine}world", _outputs["MY_OUTPUT"]);
+                Assert.Equal($"HELLO{Environment.NewLine}AGAIN", _outputs["MY_OUTPUT_2"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_SpecialCharacters()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<=EOF",
+                    "hello",
+                    "one",
+                    "=EOF",
+                    "MY_OUTPUT_2<<<EOF",
+                    "hello",
+                    "two",
+                    "<EOF",
+                    "MY_OUTPUT_3<<EOF",
+                    "hello",
+                    string.Empty,
+                    "three",
+                    string.Empty,
+                    "EOF",
+                    "MY_OUTPUT_4<<EOF",
+                    "hello=four",
+                    "EOF",
+                    "MY_OUTPUT_5<<EOF",
+                    " EOF",
+                    "EOF",
+                };
+                WriteContent(stateFile, content);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(5, _outputs.Count);
+                Assert.Equal($"hello{Environment.NewLine}one", _outputs["MY_OUTPUT"]);
+                Assert.Equal($"hello{Environment.NewLine}two", _outputs["MY_OUTPUT_2"]);
+                Assert.Equal($"hello{Environment.NewLine}{Environment.NewLine}three{Environment.NewLine}", _outputs["MY_OUTPUT_3"]);
+                Assert.Equal($"hello=four", _outputs["MY_OUTPUT_4"]);
+                Assert.Equal($" EOF", _outputs["MY_OUTPUT_5"]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_MissingNewLine()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<EOF",
+                    "line one",
+                    "line two",
+                    "line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, " ");
+                var ex = Assert.Throws<Exception>(() => _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null));
+                Assert.Contains("Matching delimiter not found", ex.Message);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_MissingNewLineMultipleLines()
+        {
+            using (var hostContext = Setup())
+            {
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<EOF",
+                    @"line one
+                    line two
+                    line three",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, " ");
+                var ex = Assert.Throws<Exception>(() => _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null));
+                Assert.Contains("EOF marker missing new line", ex.Message);
+            }
+        }
+
+#if OS_WINDOWS
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputFileCommand_Heredoc_PreservesNewline()
+        {
+            using (var hostContext = Setup())
+            {
+                var newline = "\n";
+                var stateFile = Path.Combine(_rootDirectory, "heredoc");
+                var content = new List<string>
+                {
+                    "MY_OUTPUT<<EOF",
+                    "hello",
+                    "world",
+                    "EOF",
+                };
+                WriteContent(stateFile, content, newline: newline);
+                _setOutputFileCommand.ProcessCommand(_executionContext.Object, stateFile, null);
+                Assert.Equal(0, _issues.Count);
+                Assert.Equal(1, _outputs.Count);
+                Assert.Equal($"hello{newline}world", _outputs["MY_OUTPUT"]);
+            }
+        }
+#endif
+
+        private void WriteContent(
+            string path,
+            List<string> content,
+            string newline = null)
+        {
+            if (string.IsNullOrEmpty(newline))
+            {
+                newline = Environment.NewLine;
+            }
+
+            var encoding = new UTF8Encoding(true); // Emit BOM
+            var contentStr = string.Join(newline, content);
+            File.WriteAllText(path, contentStr, encoding);
+        }
+
+        private TestHostContext Setup([CallerMemberName] string name = "")
+        {
+            _issues = new List<Tuple<DTWebApi.Issue, string>>();
+            _outputs = new Dictionary<string, string>();
+
+            var hostContext = new TestHostContext(this, name);
+
+            // Trace
+            _trace = hostContext.GetTrace();
+
+            // Directory for test data
+            var workDirectory = hostContext.GetDirectory(WellKnownDirectory.Work);
+            ArgUtil.NotNullOrEmpty(workDirectory, nameof(workDirectory));
+            Directory.CreateDirectory(workDirectory);
+            _rootDirectory = Path.Combine(workDirectory, nameof(SetOutputFileCommandL0));
+            Directory.CreateDirectory(_rootDirectory);
+
+            // Execution context
+            _executionContext = new Mock<IExecutionContext>();
+            _executionContext.Setup(x => x.Global)
+                .Returns(new GlobalContext
+                {
+                    EnvironmentVariables = new Dictionary<string, string>(VarUtil.EnvironmentVariableKeyComparer),
+                    WriteDebug = true,
+                });
+            _executionContext.Setup(x => x.AddIssue(It.IsAny<DTWebApi.Issue>(), It.IsAny<string>()))
+                .Callback((DTWebApi.Issue issue, string logMessage) =>
+                {
+                    _issues.Add(new Tuple<DTWebApi.Issue, string>(issue, logMessage));
+                    var message = !string.IsNullOrEmpty(logMessage) ? logMessage : issue.Message;
+                    _trace.Info($"Issue '{issue.Type}': {message}");
+                });
+            _executionContext.Setup(x => x.Write(It.IsAny<string>(), It.IsAny<string>()))
+                .Callback((string tag, string message) =>
+                {
+                    _trace.Info($"{tag}{message}");
+                });
+
+            var reference = string.Empty;
+            _executionContext.Setup(x => x.SetOutput(It.IsAny<string>(), It.IsAny<string>(), out reference))
+              .Callback((string name, string value, out string reference) =>
+              {
+                reference = value;
+                _outputs[name] = value;
+              });
+
+            // SetOutputFileCommand
+            _setOutputFileCommand = new SetOutputFileCommand();
+            _setOutputFileCommand.Initialize(hostContext);
+
+            return hostContext;
+        }
+    }
+}