feat(stylus): support import by allowing files in deps

Author: alexeagle

packages/stylus/src/index.bzl

@@ -9,7 +9,7 @@ def _stylus_binary(ctx):
     output = ctx.actions.declare_file(src.basename[:-5] + ".css")
     ctx.actions.run(
         outputs = [output],
-        inputs = [src],
+        inputs = [src] + ctx.files.deps,
         executable = ctx.executable._compiler,
         arguments = [
             "--out",
@@ -28,6 +28,9 @@ stylus_binary = rule(
             mandatory = True,
             allow_single_file = True,
         ),
+        "deps": attr.label_list(
+            allow_files = True,
+        ),
         "_compiler": attr.label(
             default = Label("@npm//stylus/bin:stylus"),
             cfg = "host",

packages/stylus/test/BUILD.bazel

@@ -3,6 +3,7 @@ load("@npm_bazel_stylus//:index.bzl", "stylus_binary")
 stylus_binary(
     name = "styles",
     src = "file.styl",
+    deps = ["liba.styl"],
 )
 
 load("@build_bazel_rules_nodejs//:defs.bzl", "nodejs_test")

packages/stylus/test/file.styl

@@ -1,3 +1,5 @@
+@import "liba"
+
 body {
   font: 14px/1.5 Helvetica, arial, sans-serif;
   #logo {

packages/stylus/test/liba.styl

@@ -0,0 +1,2 @@
+.bar
+  width: 10px;

packages/stylus/test/stylus_binary_spec.js

@@ -5,3 +5,7 @@ if (content.indexOf('body #logo') < 0) {
   console.error('Expected the css file to be transformed');
   process.exitCode = 1;
 }
+if (content.indexOf('width: 10px') < 0) {
+  console.error('Expected the css file to be transformed');
+  process.exitCode = 1;
+}