build(flake): Use treefmt as nix formatter

This allows us to also keep markdown and other documents, that aren't
nix, formatted.

1 files changed, 86 insertions, 0 deletions

diff --git a/treefmt.nix b/treefmt.nix
new file mode 100644
index 0000000..e2c6aea
--- /dev/null
+++ b/treefmt.nix
@@ -0,0 +1,86 @@
+{
+  treefmt-nix,
+  pkgs,
+}:
+treefmt-nix.lib.evalModule pkgs (
+  {pkgs, ...}: {
+    # Used to find the project root
+    projectRootFile = "flake.nix";
+
+    programs = {
+      alejandra.enable = true;
+      rustfmt.enable = true;
+      clang-format.enable = true;
+      mdformat.enable = true;
+      shfmt = {
+        enable = true;
+        indent_size = 4;
+      };
+      shellcheck.enable = true;
+      prettier = {
+        settings = {
+          arrowParens = "always";
+          bracketSameLine = false;
+          bracketSpacing = true;
+          editorconfig = true;
+          embeddedLanguageFormatting = "auto";
+          endOfLine = "lf";
+          # experimentalTernaries = false;
+          htmlWhitespaceSensitivity = "css";
+          insertPragma = false;
+          jsxSingleQuote = true;
+          printWidth = 80;
+          proseWrap = "always";
+          quoteProps = "consistent";
+          requirePragma = false;
+          semi = true;
+          singleAttributePerLine = true;
+          singleQuote = true;
+          trailingComma = "all";
+          useTabs = false;
+          vueIndentScriptAndStyle = false;
+
+          tabWidth = 4;
+          overrides = {
+            files = ["*.js"];
+            options.tabwidth = 2;
+          };
+        };
+      };
+      stylua = {
+        enable = true;
+        settings = {
+          sort_requires.enabled = true;
+          column_width = 120;
+          line_endings = "Unix";
+          indent_type = "Spaces";
+          indent_width = 2;
+          quote_style = "ForceDouble";
+          call_parentheses = "Always";
+          # space_after_function_names = "Never";
+          collapse_simple_statement = "Always";
+        };
+      };
+      ruff = {
+        enable = true;
+        format = true;
+      };
+      taplo.enable = true;
+    };
+
+    settings = {
+      global.excludes = [
+        "CHANGELOG.md"
+        "NEWS.md"
+      ];
+      formatter = {
+        clang-format = {
+          options = ["--style" "GNU"];
+        };
+        shfmt = {
+          includes = ["*.bash"];
+        };
+      };
+    };
+  }
+)