pyright: init

README.md

@@ -315,6 +315,7 @@ functions.
 * [pinact](programs/pinact.nix)
 * [prettier](programs/prettier.nix)
 * [protolint](programs/protolint.nix)
+* [pyright](programs/pyright.nix)
 * [qmlformat](programs/qmlformat.nix)
 * [rstfmt](programs/rstfmt.nix)
 * [rubocop](programs/rubocop.nix)

programs/pyright.nix

@@ -0,0 +1,117 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+let
+  escapePath = lib.replaceStrings [ "/" "." ] [ "-" "" ];
+in
+{
+  meta.maintainers = [ "otavio" ];
+  # Example contains store paths
+  meta.skipExample = true;
+
+  options.programs.pyright = {
+    enable = lib.mkEnableOption "pyright";
+    package = lib.mkPackageOption pkgs "pyright" { };
+    directories = lib.mkOption {
+      description = ''
+        Directories to run pyright in.
+
+        Pyright auto-discovers `pyrightconfig.json` or `pyproject.toml`
+        (`[tool.pyright]`) starting from the directory it is invoked in.
+        Use `extraPaths` in that config to add module search paths —
+        pyright does not read the `PYTHONPATH` environment variable.
+      '';
+      type = lib.types.attrsOf (
+        lib.types.submodule (
+          { name, ... }:
+          {
+            options = {
+              directory = lib.mkOption {
+                type = lib.types.str;
+                default = name;
+                description = ''
+                  Directory to run pyright in, relative to the project root.
+                  The empty string means the project root itself — no `cd`
+                  is performed.
+                '';
+              };
+              options = lib.mkOption {
+                type = lib.types.listOf lib.types.str;
+                default = [ ];
+                example = [ "--warnings" ];
+                description = "Options to pass to pyright";
+              };
+              modules = lib.mkOption {
+                type = lib.types.listOf lib.types.str;
+                default = [ "" ];
+                example = [
+                  "mymodule"
+                  "tests"
+                ];
+                description = "Modules to check (passed as positional file/directory arguments)";
+              };
+            };
+          }
+        )
+      );
+      default = {
+        "" = { };
+      };
+      example = {
+        "" = {
+          modules = [
+            "mymodule"
+            "tests"
+          ];
+        };
+        "subdir" = { };
+      };
+    };
+  };
+
+  config = lib.mkIf config.programs.pyright.enable {
+    settings.formatter = lib.mapAttrs' (
+      name: cfg:
+      let
+        nonEmptyModules = lib.filter (m: m != "") cfg.modules;
+        cdLine = lib.optionalString (cfg.directory != "") "cd ${lib.escapeShellArg cfg.directory}";
+        args = lib.escapeShellArgs (cfg.options ++ nonEmptyModules);
+      in
+      lib.nameValuePair "pyright${lib.optionalString (name != "") "-${escapePath name}"}" {
+        command = pkgs.bash;
+        # Pyright resolves imports from a whole-module context, not per file,
+        # so the wrapper ignores the file path treefmt passes as `$0` and always
+        # invokes pyright on the configured `modules` (or the whole `directory`
+        # when `modules` is empty). With treefmt's batch-size limit this means
+        # pyright may be invoked more than once per directory on large file sets
+        # — each call redundantly type-checks the same modules.
+        #
+        # `treefmt --stdin` is not supported: pyright type-checks the on-disk
+        # modules regardless of what is piped in, so editor integrations should
+        # use pyright's language server directly. A clean opt-out will become
+        # possible once treefmt's Stdin Specification lands
+        # (numtide/treefmt#586).
+        options = [
+          "-eucx"
+          ''
+            ${cdLine}
+            exec ${lib.getExe config.programs.pyright.package} ${args}
+          ''
+        ];
+        includes = lib.concatMap (
+          module:
+          let
+            prefix = lib.optional (cfg.directory != "") cfg.directory ++ lib.optional (module != "") module;
+          in
+          [
+            (lib.concatStringsSep "/" (prefix ++ [ "*.py" ]))
+            (lib.concatStringsSep "/" (prefix ++ [ "*.pyi" ]))
+          ]
+        ) cfg.modules;
+      }
+    ) config.programs.pyright.directories;
+  };
+}