Add missing test for arguments to node programs

This would have prevented the need to revert a commit:
404c4b0

examples/rollup/BUILD.bazel

@@ -12,6 +12,10 @@ nodejs_binary(
     name = "rollup",
     entry_point = "rollup/bin/rollup",
     node_modules = ":node_modules",
+    # Tests that templated_args works
+    # NB: Space before the / is needed to prevent shell on Windows from
+    # converting this argument to a path under C:\
+    templated_args = ["--intro", "' /*Generated by Bazel*/'"],
 )
 
 load(":rollup.bzl", "rollup")

examples/rollup/rollup.spec.js

@@ -5,7 +5,7 @@ describe('bundling', () => {
     // TODO(#32) Can shorten the path if https://github.com/bazelbuild/rules_nodejs/issues/32 is resolved
     const bundle = 'build_bazel_rules_nodejs/examples/rollup/bundle.js';
     const actual = fs.readFileSync(require.resolve(bundle), { encoding: 'utf-8' });
-    const expected = 'const name = \'Alice\';\n\nconsole.log(`Hello, ${name}`);\n';
+    const expected = '/*Generated by Bazel*/\n\nconst name = \'Alice\';\n\nconsole.log(`Hello, ${name}`);\n';
     expect(actual).toEqual(expected);
   });
 });

internal/devmode_js_sources.bzl

@@ -1,4 +1,4 @@
-load(":node.bzl", "sources_aspect", "expand_location_into_runfiles")
+load(":node.bzl", "sources_aspect", "expand_path_into_runfiles")
 
 def _devmode_js_sources_impl(ctx):
   files = depset()
@@ -10,7 +10,7 @@ def _devmode_js_sources_impl(ctx):
       files += d.files
 
   ctx.actions.write(ctx.outputs.manifest, "".join([
-    expand_location_into_runfiles(ctx, f.path) + "\n" for f in files
+    expand_path_into_runfiles(ctx, f.path) + "\n" for f in files
   ]))
   return [DefaultInfo(files = files)]
 

internal/node.bzl

@@ -61,13 +61,20 @@ def _write_loader_script(ctx):
       executable=True,
   )
 
-def expand_location_into_runfiles(ctx, input):
-  """Given a string that might contain $(location) label expansions,
+def expand_location_into_runfiles(ctx, path):
+  """If the path has a location expansion, expand it. Otherwise return as-is.
+  """
+  if path.find('$(location') < 0:
+    return path
+  return expand_path_into_runfiles(ctx, path)
+
+def expand_path_into_runfiles(ctx, path):
+  """Given a file path that might contain a $(location) label expansion,
    provide the path to the file in runfiles.
    See https://docs.bazel.build/versions/master/skylark/lib/ctx.html#expand_location
   """
   targets = ctx.attr.data if hasattr(ctx.attr, "data") else []
-  expanded = ctx.expand_location(input, targets)
+  expanded = ctx.expand_location(path, targets)
   if expanded.startswith(ctx.bin_dir.path):
     expanded = expanded[len(ctx.bin_dir.path + "/"):]
   if expanded.startswith(ctx.genfiles_dir.path):