Support custom file extensions with editor config (#1346)

closes #1273

Src/CSharpier.Cli/EditorConfig/EditorConfigSections.cs

@@ -11,15 +11,19 @@ internal class EditorConfigSections
 
     public PrinterOptions? ConvertToPrinterOptions(string filePath)
     {
-        if (!(filePath.EndsWith(".cs") || filePath.EndsWith(".csx")))
+        var sections = this.SectionsIncludingParentFiles.Where(o => o.IsMatch(filePath)).ToList();
+        var resolvedConfiguration = new ResolvedConfiguration(sections);
+
+        var formatter =
+            resolvedConfiguration.Formatter
+            ?? (filePath.EndsWith(".cs") || filePath.EndsWith(".csx") ? "csharp" : null);
+
+        if (formatter == null)
         {
             return null;
         }
 
-        var sections = this.SectionsIncludingParentFiles.Where(o => o.IsMatch(filePath)).ToList();
-        var resolvedConfiguration = new ResolvedConfiguration(sections);
-
-        var printerOptions = new PrinterOptions { Formatter = "csharp" };
+        var printerOptions = new PrinterOptions { Formatter = formatter };
 
         if (resolvedConfiguration.MaxLineLength is { } maxLineLength)
         {
@@ -56,6 +60,7 @@ private class ResolvedConfiguration
         public int? TabWidth { get; }
         public int? MaxLineLength { get; }
         public EndOfLine? EndOfLine { get; }
+        public string? Formatter { get; }
 
         public ResolvedConfiguration(List<Section> sections)
         {
@@ -100,6 +105,8 @@ public ResolvedConfiguration(List<Section> sections)
             {
                 this.EndOfLine = result;
             }
+
+            this.Formatter = sections.LastOrDefault(o => o.Formatter is not null)?.Formatter;
         }
     }
 }

Src/CSharpier.Cli/EditorConfig/Section.cs

@@ -11,6 +11,7 @@ internal class Section
     public string? TabWidth { get; }
     public string? MaxLineLength { get; }
     public string? EndOfLine { get; }
+    public string? Formatter { get; }
 
     public Section(SectionData section, string directory)
     {
@@ -20,6 +21,7 @@ public Section(SectionData section, string directory)
         this.TabWidth = section.Keys["tab_width"];
         this.MaxLineLength = section.Keys["max_line_length"];
         this.EndOfLine = section.Keys["end_of_line"];
+        this.Formatter = section.Keys["csharpier_formatter"];
     }
 
     public bool IsMatch(string fileName)

Src/CSharpier.Tests/OptionsProviderTests.cs

@@ -203,7 +203,7 @@ public async Task Should_Return_UseTabs_With_Yaml()
     }
 
     [Test]
-    public async Task Should_Return_TabWidth_For_Overrid()
+    public async Task Should_Return_TabWidth_For_Override()
     {
         var context = new TestContext();
         context.WhenAFileExists(
@@ -528,6 +528,24 @@ public async Task Should_Support_EditorConfig_Tabs_With_Glob_Braces_Multiples()
         result.IndentSize.Should().Be(2);
     }
 
+    [Test]
+    public async Task Should_Return_IndentSize_For_Formatter_In_Editorconfig()
+    {
+        var context = new TestContext();
+        context.WhenAFileExists(
+            "c:/test/.editorconfig",
+            """
+            [*.cst]
+            indent_size = 2
+            csharpier_formatter = csharp
+            """
+        );
+
+        var result = await context.CreateProviderAndGetOptionsFor("c:/test", "c:/test/test.cst");
+
+        result.IndentSize.Should().Be(2);
+    }
+
     [Test]
     public async Task Should_Find_EditorConfig_In_Parent_Directory()
     {

docs/Configuration.md

@@ -81,6 +81,7 @@ The long term plan is to improve Csharpier's ability to determine the symbol set
 
 ### Configuration Overrides ###
 _First available in 0.29.0_
+
 Overrides allows you to specify different configuration options based on glob patterns. This can be used to format non-standard extensions, or to change options based on file path. Top level options will apply to `**/*.{cs,csx}`
 
 ```json
@@ -114,7 +115,7 @@ _First available in 0.26.0_
 CSharpier supports configuration via an `.editorconfig` file. A `.csharpierrc*` file in the same directory will take priority.
 
 ```ini
-[*]
+[*.{cs|csx}]
 # Non-configurable behaviors
 charset = utf-8
 insert_final_newline = true
@@ -123,9 +124,20 @@ dotnet_sort_system_directives_first = true
 dotnet_separate_import_directive_groups = false
 
 # Configurable behaviors
-# end_of_line = lf - there is no 'auto' with a .editorconfig
+# end_of_line = lf - there is no 'auto' with an .editorconfig
 indent_style = space
 indent_size = 4
 max_line_length = 100
+```
+
+_First available in 0.29.2_
 
+Formatting non-standard file extensions using csharpier can be accomplished with the `csharpier_formatter` option
+```ini
+[*.cst]
+csharpier_formatter = csharp
+indent_style = space
+indent_size = 2
+max_line_length = 80
 ```
+