1 files changed, 35 insertions, 0 deletions
diff --git a/lua/conform/formatters/darker.lua b/lua/conform/formatters/darker.lua
new file mode 100644
index 0000000..5f47e6b
--- /dev/null
+++ b/lua/conform/formatters/darker.lua
@@ -0,0 +1,35 @@
+local util = require("conform.util")
+---@type conform.FileFormatterConfig
+return {
+  meta = {
+    url = "https://github.com/akaihola/darker",
+    description = "Run black only on changed lines.",
+  },
+  command = "darker",
+  args = function(ctx)
+    -- make sure pre-save doesn't lose changes while post-save respects
+    -- the revision setting potentially set in pyproject.toml
+    if vim.bo[ctx.buf].modified then
+      return {
+        "--quiet",
+        "--no-color",
+        "--stdout",
+        "--revision",
+        "HEAD..:STDIN:",
+        "--stdin-filename",
+        "$FILENAME",
+      }
+    else
+      return {
+        "--quiet",
+        "--no-color",
+        "--stdout",
+        "$FILENAME",
+      }
+    end
+  end,
+  cwd = util.root_file({
+    -- https://github.com/akaihola/darker#customizing-darker-black-isort-flynt-and-linter-behavior
+    "pyproject.toml",
+  }),
+}