Gemspec generation needs to handle directories (#20)

* Change gemspec build to handle directories

Author: ClareCat

ruby/private/gem/BUILD.bazel

@@ -4,6 +4,7 @@ exports_files(
     [
         "gemspec_template.tpl",
         "gem_runner.rb",
+        "gemspec_builder.rb",
     ],
     visibility = ["//visibility:public"],
 )

ruby/private/gem/gemspec.bzl

@@ -14,36 +14,42 @@ def _get_transitive_srcs(srcs, deps):
         transitive = [dep[RubyLibrary].transitive_ruby_srcs for dep in deps],
     )
 
-def _unique_elems(list):
-    _out = []
-    _prev = None
-    for elem in sorted(list):
-        if _prev != elem:
-            _out.append(elem)
-
-    return _out
-
 def _rb_gem_impl(ctx):
-    gemspec = ctx.actions.declare_file("%s.gemspec" % ctx.attr.gem_name)
+    gemspec = ctx.actions.declare_file("{}.gemspec".format(ctx.attr.gem_name))
+    metadata_file = ctx.actions.declare_file("{}_metadata".format(ctx.attr.gem_name))
 
     _ruby_files = []
-    _require_paths = []
-    for file in _get_transitive_srcs([], ctx.attr.deps).to_list():
-        _ruby_files.append(file.short_path)
-        _require_paths.append(file.dirname)
+    file_deps = _get_transitive_srcs([], ctx.attr.deps).to_list()
+    for f in file_deps:
+        _ruby_files.append(f.short_path)
 
-    _require_paths = _unique_elems(_require_paths)  # Set is not supported in Starlark
+    ctx.actions.write(
+        output = metadata_file,
+        content = struct(
+            name = ctx.attr.gem_name,
+            srcs = _ruby_files,
+            authors = ctx.attr.authors,
+            version = ctx.attr.version,
+        ).to_json(),
+    )
 
-    ctx.actions.expand_template(
-        template = ctx.file._gemspec_template,
-        output = gemspec,
-        substitutions = {
-            "{name}": "\"%s\"" % ctx.attr.gem_name,
-            "{srcs}": repr(_ruby_files),
-            "{authors}": repr(ctx.attr.authors),
-            "{version}": "\"{}\"".format(ctx.attr.version),
-            "{require_paths}": repr(_require_paths),
-        },
+    ctx.actions.run(
+        inputs = [
+            ctx.file._gemspec_template,
+            ctx.file._gemspec_builder,
+            metadata_file,
+        ] + file_deps,
+        executable = ctx.attr.ruby_interpreter.files_to_run.executable,
+        arguments = [
+            ctx.file._gemspec_builder.path,
+            "--output",
+            gemspec.path,
+            "--metadata",
+            metadata_file.path,
+            "--template",
+            ctx.file._gemspec_template.path,
+        ],
+        outputs = [gemspec],
     )
 
     return [
@@ -66,10 +72,6 @@ _ATTRS = {
     "data": attr.label_list(
         allow_files = True,
     ),
-    "_gemspec_template": attr.label(
-        allow_single_file = True,
-        default = "gemspec_template.tpl",
-    ),
     "gem_name": attr.string(),
     "srcs": attr.label_list(
         allow_files = True,
@@ -79,6 +81,23 @@ _ATTRS = {
         allow_files = True,
     ),
     "require_paths": attr.string_list(),
+    "_gemspec_template": attr.label(
+        allow_single_file = True,
+        default = "gemspec_template.tpl",
+    ),
+    "ruby_sdk": attr.string(
+        default = "@org_ruby_lang_ruby_toolchain",
+    ),
+    "ruby_interpreter": attr.label(
+        default = "@org_ruby_lang_ruby_toolchain//:ruby_bin",
+        allow_files = True,
+        executable = True,
+        cfg = "host",
+    ),
+    "_gemspec_builder": attr.label(
+        default = Label("@coinbase_rules_ruby//ruby/private/gem:gemspec_builder.rb"),
+        allow_single_file = True,
+    ),
 }
 
 rb_gemspec = rule(

ruby/private/gem/gemspec_builder.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'json'
+require 'optparse'
+
+def parse_opts
+  output_file = nil
+  metadata_file = nil
+  template_file = nil
+
+  OptionParser.new do |opts|
+    opts.on('--template [ARG]', 'Gemspec template file') do |v|
+      template_file = v
+    end
+    opts.on('--output [ARG]', 'Output file') do |v|
+      output_file = v
+    end
+    opts.on('--metadata [ARG]', 'Metadata file') do |v|
+      metadata_file = v
+    end
+    opts.on('-h', '--help') do |_v|
+      puts opts
+      exit 0
+    end
+  end.parse!
+
+  [output_file, metadata_file, template_file]
+end
+
+def add_src_file(src, new_srcs, new_require_paths)
+  return unless File.file?(src)
+
+  new_srcs << src
+  new_require_paths << File.dirname(src)
+end
+
+def parse_metadata_srcs(metadata)
+  # Files and required paths can include a directory which gemspec
+  # cannot handle. This will convert directories to individual files
+  # and update require_paths to include them..
+  srcs = metadata['srcs']
+  new_require_paths = []
+  new_srcs = []
+  srcs.each do |src|
+    if File.directory?(src)
+      Dir.glob("#{src}/**/*") do |f|
+        add_src_file(f, new_srcs, new_require_paths)
+      end
+    else
+      add_src_file(src, new_srcs, new_require_paths)
+    end
+  end
+  metadata['srcs'] = new_srcs
+  metadata['require_paths'] = new_require_paths
+  metadata
+end
+
+def main
+  output_file, metadata_file, template_file = parse_opts
+  data = File.read(template_file)
+  m = File.read(metadata_file)
+  metadata = JSON.parse(m)
+
+  metadata = parse_metadata_srcs(metadata)
+  filtered_data = data
+
+  metadata.each do |key, value|
+    replace_val = "{#{key}}"
+    filtered_data = filtered_data.gsub(replace_val, value.to_s)
+  end
+
+  File.open(output_file, 'w') do |out_file|
+    out_file.write(filtered_data)
+  end
+end
+
+main if $PROGRAM_NAME == __FILE__

ruby/private/gem/gemspec_template.tpl

@@ -1,8 +1,8 @@
 Gem::Specification.new do |s|
-  s.name          = {name}
-  s.summary       = {name}
+  s.name          = "{name}"
+  s.summary       = "{name}"
   s.authors       = {authors}
-  s.version       = {version}
+  s.version       = "{version}"
   s.files         = {srcs}
   s.require_paths = {require_paths}
 end