Address feedback

Author: devversion

tools/markdown-to-html/index.bzl

@@ -7,14 +7,22 @@ def _markdown_to_html(ctx):
   args = ctx.actions.args()
   expected_outputs = [];
 
+  # Add the bazel bin directory to the command arguments. The script needs to know about
+  # the output directory because the input files are not in the same location as the bazel
+  # bin directory.
+  args.add(ctx.bin_dir.path)
+
   for input_file in input_files:
-    basename = input_file.basename.replace('.md', '')
-    output_file = ctx.actions.declare_file("%s.html" % basename)
-    expected_outputs += [output_file]
+    # Remove the extension from the input file path. Note that we should not use `.replace`
+    # here because the extension can be also in upper case.
+    basename = input_file.basename[:-len(".md")]
+
+    # For each input file "xxx.md", we want to write an output file "xxx.html"
+    expected_outputs += [ctx.actions.declare_file("%s.html" % basename)]
 
-    # Add the input file and it's related output to the arguments that
-    # will be passed to the transformer executable.
-    args.add("%s=%s" % (input_file.path, output_file.path))
+    # Add the input file to the command line arguments that will be passed to the
+    # transform-markdown executable.
+    args.add(input_file.path)
 
   # Run the transform markdown executable that transforms the specified source files.
   # Note that we should specify the outputs here because Bazel can then throw an error

tools/markdown-to-html/transform-markdown.ts

@@ -4,11 +4,15 @@
  */
 
 import {readFileSync, writeFileSync} from 'fs';
+import {join} from 'path';
 
 // These types lack type definitions.
 const marked = require('marked');
 const highlightJs = require('highlight.js');
 
+// Regular expression that matches the markdown extension of a given path.
+const markdownExtension = /.md$/;
+
 // Setup the default options for converting markdown to HTML.
 marked.setOptions({
   // Implement a highlight function that converts the code block into a highlighted
@@ -23,15 +27,14 @@ marked.setOptions({
 });
 
 if (require.main === module) {
-  // The script expects the input files to be specified in the following format:
-  //    {input_file_path}={output_file_path}
-  // We have to know the output paths because the input path and output path differ
-  // fundamentally within the Bazel sandbox.
-  const inputFiles = process.argv.slice(2).map(argument => argument.split('='));
+  // The script expects the bazel-bin path as first argument. All remaining arguments will be
+  // considered as markdown input files that need to be transformed.
+  const [bazelBinPath, ...inputFiles] = process.argv.slice(2);
 
   // Walk through each input file and write transformed markdown output to the specified
-  // output path.
-  inputFiles.forEach(([inputPath, outputPath]) => {
+  // Bazel bin directory.
+  inputFiles.forEach(inputPath => {
+    const outputPath = join(bazelBinPath, inputPath.replace(markdownExtension, '.html'));
     writeFileSync(outputPath, marked(readFileSync(inputPath, 'utf8')));
   });
 }