Get flake8 working as an aspect

BUILD

@@ -0,0 +1,3 @@
+package(default_visibility = ["//visibility:public"])
+
+exports_files(["setup.cfg"])

setup.cfg

@@ -18,7 +18,7 @@ index-servers = pypi
 shitlist = pip,pkg_resources,setuptools
 
 [flake8]
-extend-ignore = E203,E501,F405,F403,E731
+extend-ignore = E203,E501,F405,F403,E731,E306
 
 [pypi]
 repository = https://pypi.python.org/pypi

tools/autoflake/BUILD

@@ -3,5 +3,8 @@ py_binary(
     main = "__main__.py",
     deps = [
         py_requirement("autoflake"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/flake8/BUILD

@@ -1,7 +1,12 @@
+exports_files(["flake8.cfg"], visibility=["//visibility:public"])
+
 py_binary(
     name = "flake8",
     main = "__main__.py",
     deps = [
         py_requirement("flake8"),
     ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/flake8/flake8.bzl

@@ -0,0 +1,65 @@
+"""Linting for Python using Aspects."""
+
+
+def _flake8_aspect_impl(target, ctx):
+    if hasattr(ctx.rule.attr, 'srcs'):
+        flake8 = ctx.attr._flake8.files_to_run
+        config = ctx.attr._config.files.to_list()[0]
+
+        files = []
+        for src in ctx.rule.attr.srcs:
+            for f in src.files.to_list():
+                if f.extension == "py":
+                    files.append(f)
+
+        if files:
+            report = ctx.actions.declare_file(ctx.label.name + ".report")
+        else:
+            return []
+
+        args = ["--config", config.path, "--tee", "--output-file", report.path]
+        for f in files:
+            args.append(f.path)
+
+        ctx.actions.run(
+            executable = flake8,
+            inputs = files,
+            tools = ctx.attr._config.files.to_list() + ctx.attr._flake8.files.to_list(),
+            arguments = args,
+            outputs = [report],
+            mnemonic = "Flake8",
+        )
+
+        return [
+            OutputGroupInfo(flake8_checks = depset([report]))
+        ]
+
+    return []
+
+
+flake8_aspect = aspect(
+    implementation = _flake8_aspect_impl,
+    attr_aspects = ['deps'],
+    attrs = {
+        '_flake8': attr.label(default="//tools/flake8"),
+        '_config': attr.label(
+            default="//:setup.cfg",
+            executable=False,
+            allow_single_file=True
+        ),
+    }
+)
+
+
+def _flake8_rule_impl(ctx):
+    ready_targets = [dep for dep in ctx.attr.deps if "flake8_checks" in dir(dep[OutputGroupInfo])]
+    files = depset([], transitive = [dep[OutputGroupInfo].flake8_checks for dep in ready_targets])
+    return [DefaultInfo(files = files)]
+
+
+flake8 = rule(
+    implementation = _flake8_rule_impl,
+    attrs = {
+        'deps' : attr.label_list(aspects = [flake8_aspect]),
+    },
+)

tools/isort/BUILD

@@ -3,5 +3,9 @@ py_binary(
     main = "__main__.py",
     deps = [
         py_requirement("isort"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
+
 )

tools/openapi/BUILD

@@ -3,5 +3,8 @@ py_binary(
     main = "__main__.py",
     deps = [
         py_requirement("openapi-spec-validator"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/python/defs.bzl

@@ -14,6 +14,9 @@ load("@rules_zapp//zapp:zapp.bzl",
      "zapp_binary",
 )
 
+load("//tools/flake8:flake8.bzl",
+     "flake8",
+)
 
 def py_requirement(*args, **kwargs):
     """A re-export of requirement()"""
@@ -208,6 +211,12 @@ def py_project(name=None,
         ],
     )
 
+    # if lib_srcs:
+    #     flake8(
+    #         name = "flake8",
+    #         deps = [lib_name],
+    #     )
+
     if main:
         py_binary(
             name=name,

tools/sphinx/BUILD

@@ -8,5 +8,8 @@ py_binary(
         py_requirement("sphinxcontrib-openapi"),
         py_requirement("sphinxcontrib-programoutput"),
         py_requirement("livereload"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/unify/BUILD

@@ -3,5 +3,8 @@ py_binary(
     main = "__main__.py",
     deps = [
         py_requirement("unify"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/xfmt/BUILD

@@ -5,5 +5,8 @@ py_binary(
         py_requirement("beautifulsoup4"),
         py_requirement("click"),
         py_requirement("lxml"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )

tools/yamllint/BUILD

@@ -4,5 +4,8 @@ py_binary(
     main = "__main__.py",
     deps = [
         py_requirement("yamllint"),
-    ]
+    ],
+    visibility = [
+        "//visibility:public"
+    ],
 )