expose binaries from pip

pip/BUILD.bazel

@@ -1,5 +1,19 @@
 load("@rules_python//python:defs.bzl", "py_binary")
 load("@py_deps//:requirements.bzl", "requirement")
+load(":binary.bzl", "pip_binary")
+
+pip_binary(name = "black")
+
+pip_binary(name = "isort")
+
+pip_binary(name = "mypy")
+
+pip_binary(name = "pylint")
+
+pip_binary(
+    name = "protoc-gen-mypy",
+    pkg = "mypy-protobuf",
+)
 
 py_binary(
     name = "update",

pip/binary.bzl

@@ -0,0 +1,28 @@
+load("@bazel_skylib//rules:copy_file.bzl", "copy_file")
+load("@py_deps//:requirements.bzl", "requirement")
+
+def pip_binary(name, pkg = None):
+    "Expose a binary from pip as an executable for linting."
+
+    if not pkg:
+        pkg = name
+
+    binary_prefix = requirement(pkg).replace(":pkg", ":bin/" + name)
+
+    copy_file(
+        name = name + "_bin",
+        src = select({
+            "@platforms//os:windows": binary_prefix + ".exe",
+            "//conditions:default": binary_prefix,
+        }),
+        out = name + "_bin.py",
+    )
+
+    native.py_binary(
+        name = name,
+        srcs = [":" + name + "_bin.py"],
+        main = ":" + name + "_bin.py",
+        deps = [
+            requirement(pkg),
+        ],
+    )