chore: add .gitattributes to enforce LF line endings repo-wide

.editorconfig

@@ -0,0 +1,19 @@
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.cs]
+indent_style = space
+indent_size = 4
+
+[*.{csproj,sln}]
+indent_style = space
+indent_size = 2
+
+[*.{json,yaml,yml}]
+indent_style = space
+indent_size = 2

.gitattributes

@@ -0,0 +1,64 @@
+# Normalize all text files to LF in the repository.
+# This eliminates CRLF drift on Windows (core.autocrlf=true) so that
+# `npm run generate` never produces spurious line-ending diffs.
+
+# Default: auto-detect text files and normalize to LF on checkout.
+* text=auto eol=lf
+
+# --- Source code ---
+*.py    text eol=lf
+*.ts    text eol=lf
+*.tsx   text eol=lf
+*.js    text eol=lf
+*.mjs   text eol=lf
+*.rs    text eol=lf
+*.go    text eol=lf
+*.cs    text eol=lf
+*.tsp   text eol=lf
+*.astro text eol=lf
+*.css   text eol=lf
+*.html  text eol=lf
+
+# --- Config / data ---
+*.json      text eol=lf
+*.yaml      text eol=lf
+*.yml       text eol=lf
+*.toml      text eol=lf
+*.md        text eol=lf
+*.mdx       text eol=lf
+*.txt       text eol=lf
+*.prompty   text eol=lf
+*.cfg       text eol=lf
+*.conf      text eol=lf
+*.mod       text eol=lf
+*.sum       text eol=lf
+
+# --- Project files ---
+*.csproj    text eol=lf
+*.sln       text eol=lf
+*.ps1       text eol=lf
+*.bat       text eol=lf
+
+# --- Dotfiles (no extension — treat as text) ---
+.gitignore      text eol=lf
+.gitattributes  text eol=lf
+.dockerignore   text eol=lf
+.vscodeignore   text eol=lf
+.babelrc        text eol=lf
+.example        text eol=lf
+Dockerfile      text eol=lf
+
+# --- Truly binary files --- keep as-is
+*.png   binary
+*.exe   binary
+*.svg   text eol=lf
+
+# --- Lock files: text but don't diff ---
+*.lock          text eol=lf -diff
+package-lock.json text eol=lf -diff
+Cargo.lock      text eol=lf -diff
+
+# --- Generated marker (no content) ---
+*.typed         text eol=lf
+*.tsbuildinfo   text eol=lf
+*.tracy         text eol=lf

runtime/csharp/Prompty.Core.Tests/Model/core/FileNotFoundErrorConversionTests.cs

@@ -0,0 +1,122 @@
+using Xunit;
+
+#pragma warning disable IDE0130
+namespace Prompty.Core;
+#pragma warning restore IDE0130
+
+
+public class FileNotFoundErrorConversionTests
+{
+    [Fact]
+    public void LoadYamlInput()
+    {
+        string yamlData = """
+message: "Prompty file not found: ./chat.prompty"
+path: ./chat.prompty
+
+""";
+
+        var instance = FileNotFoundError.FromYaml(yamlData);
+
+        Assert.NotNull(instance);
+        Assert.Equal("Prompty file not found: ./chat.prompty", instance.Message);
+        Assert.Equal("./chat.prompty", instance.Path);
+    }
+
+    [Fact]
+    public void LoadJsonInput()
+    {
+        string jsonData = """
+{
+  "message": "Prompty file not found: ./chat.prompty",
+  "path": "./chat.prompty"
+}
+""";
+
+        var instance = FileNotFoundError.FromJson(jsonData);
+        Assert.NotNull(instance);
+        Assert.Equal("Prompty file not found: ./chat.prompty", instance.Message);
+        Assert.Equal("./chat.prompty", instance.Path);
+    }
+
+    [Fact]
+    public void RoundtripJson()
+    {
+        // Test that FromJson -> ToJson -> FromJson produces equivalent data
+        string jsonData = """
+{
+  "message": "Prompty file not found: ./chat.prompty",
+  "path": "./chat.prompty"
+}
+""";
+
+        var original = FileNotFoundError.FromJson(jsonData);
+        Assert.NotNull(original);
+
+        var json = original.ToJson();
+        Assert.False(string.IsNullOrEmpty(json));
+
+        var reloaded = FileNotFoundError.FromJson(json);
+        Assert.NotNull(reloaded);
+        Assert.Equal("Prompty file not found: ./chat.prompty", reloaded.Message);
+        Assert.Equal("./chat.prompty", reloaded.Path);
+    }
+
+    [Fact]
+    public void RoundtripYaml()
+    {
+        // Test that FromYaml -> ToYaml -> FromYaml produces equivalent data
+        string yamlData = """
+message: "Prompty file not found: ./chat.prompty"
+path: ./chat.prompty
+
+""";
+
+        var original = FileNotFoundError.FromYaml(yamlData);
+        Assert.NotNull(original);
+
+        var yaml = original.ToYaml();
+        Assert.False(string.IsNullOrEmpty(yaml));
+
+        var reloaded = FileNotFoundError.FromYaml(yaml);
+        Assert.NotNull(reloaded);
+        Assert.Equal("Prompty file not found: ./chat.prompty", reloaded.Message);
+        Assert.Equal("./chat.prompty", reloaded.Path);
+    }
+
+    [Fact]
+    public void ToJsonProducesValidJson()
+    {
+        string jsonData = """
+{
+  "message": "Prompty file not found: ./chat.prompty",
+  "path": "./chat.prompty"
+}
+""";
+
+        var instance = FileNotFoundError.FromJson(jsonData);
+        var json = instance.ToJson();
+
+        // Verify it's valid JSON by parsing it
+        var parsed = System.Text.Json.JsonDocument.Parse(json);
+        Assert.NotNull(parsed);
+    }
+
+    [Fact]
+    public void ToYamlProducesValidYaml()
+    {
+        string yamlData = """
+message: "Prompty file not found: ./chat.prompty"
+path: ./chat.prompty
+
+""";
+
+        var instance = FileNotFoundError.FromYaml(yamlData);
+        var yaml = instance.ToYaml();
+
+        // Verify it's valid YAML by parsing it
+        var deserializer = new YamlDotNet.Serialization.DeserializerBuilder().Build();
+        var parsed = deserializer.Deserialize<object>(yaml);
+        Assert.NotNull(parsed);
+    }
+}

runtime/csharp/Prompty.Core.Tests/Model/core/InvokerErrorConversionTests.cs

@@ -0,0 +1,132 @@
+using Xunit;
+
+#pragma warning disable IDE0130
+namespace Prompty.Core;
+#pragma warning restore IDE0130
+
+
+public class InvokerErrorConversionTests
+{
+    [Fact]
+    public void LoadYamlInput()
+    {
+        string yamlData = """
+message: "No renderer registered for key: jinja2"
+component: renderer
+key: jinja2
+
+""";
+
+        var instance = InvokerError.FromYaml(yamlData);
+
+        Assert.NotNull(instance);
+        Assert.Equal("No renderer registered for key: jinja2", instance.Message);
+        Assert.Equal("renderer", instance.Component);
+        Assert.Equal("jinja2", instance.Key);
+    }
+
+    [Fact]
+    public void LoadJsonInput()
+    {
+        string jsonData = """
+{
+  "message": "No renderer registered for key: jinja2",
+  "component": "renderer",
+  "key": "jinja2"
+}
+""";
+
+        var instance = InvokerError.FromJson(jsonData);
+        Assert.NotNull(instance);
+        Assert.Equal("No renderer registered for key: jinja2", instance.Message);
+        Assert.Equal("renderer", instance.Component);
+        Assert.Equal("jinja2", instance.Key);
+    }
+
+    [Fact]
+    public void RoundtripJson()
+    {
+        // Test that FromJson -> ToJson -> FromJson produces equivalent data
+        string jsonData = """
+{
+  "message": "No renderer registered for key: jinja2",
+  "component": "renderer",
+  "key": "jinja2"
+}
+""";
+
+        var original = InvokerError.FromJson(jsonData);
+        Assert.NotNull(original);
+
+        var json = original.ToJson();
+        Assert.False(string.IsNullOrEmpty(json));
+
+        var reloaded = InvokerError.FromJson(json);
+        Assert.NotNull(reloaded);
+        Assert.Equal("No renderer registered for key: jinja2", reloaded.Message);
+        Assert.Equal("renderer", reloaded.Component);
+        Assert.Equal("jinja2", reloaded.Key);
+    }
+
+    [Fact]
+    public void RoundtripYaml()
+    {
+        // Test that FromYaml -> ToYaml -> FromYaml produces equivalent data
+        string yamlData = """
+message: "No renderer registered for key: jinja2"
+component: renderer
+key: jinja2
+
+""";
+
+        var original = InvokerError.FromYaml(yamlData);
+        Assert.NotNull(original);
+
+        var yaml = original.ToYaml();
+        Assert.False(string.IsNullOrEmpty(yaml));
+
+        var reloaded = InvokerError.FromYaml(yaml);
+        Assert.NotNull(reloaded);
+        Assert.Equal("No renderer registered for key: jinja2", reloaded.Message);
+        Assert.Equal("renderer", reloaded.Component);
+        Assert.Equal("jinja2", reloaded.Key);
+    }
+
+    [Fact]
+    public void ToJsonProducesValidJson()
+    {
+        string jsonData = """
+{
+  "message": "No renderer registered for key: jinja2",
+  "component": "renderer",
+  "key": "jinja2"
+}
+""";
+
+        var instance = InvokerError.FromJson(jsonData);
+        var json = instance.ToJson();
+
+        // Verify it's valid JSON by parsing it
+        var parsed = System.Text.Json.JsonDocument.Parse(json);
+        Assert.NotNull(parsed);
+    }
+
+    [Fact]
+    public void ToYamlProducesValidYaml()
+    {
+        string yamlData = """
+message: "No renderer registered for key: jinja2"
+component: renderer
+key: jinja2
+
+""";
+
+        var instance = InvokerError.FromYaml(yamlData);
+        var yaml = instance.ToYaml();
+
+        // Verify it's valid YAML by parsing it
+        var deserializer = new YamlDotNet.Serialization.DeserializerBuilder().Build();
+        var parsed = deserializer.Deserialize<object>(yaml);
+        Assert.NotNull(parsed);
+    }
+}