Test that grammars.yml lists the right scopes for each submodule

convert-grammars now supports a few flags that we can use to make it
dump out the YAML just for the local grammar submodules. We can then
compare this to the YAML that's actually in grammars.yml to check that
they're the same. If they aren't, grammars.yml needs to be updated.
This will help catch mistakes like using the wrong scope name.

script/convert-grammars

@@ -2,6 +2,7 @@
 
 require 'json'
 require 'net/http'
+require 'optparse'
 require 'plist'
 require 'set'
 require 'tmpdir'
@@ -13,6 +14,13 @@ GRAMMARS_PATH = File.join(ROOT, "grammars")
 SOURCES_FILE = File.join(ROOT, "grammars.yml")
 CSONC = File.join(ROOT, "node_modules", ".bin", "csonc")
 
+$options = {
+  :add => false,
+  :install => true,
+  :output => SOURCES_FILE,
+  :remote => true,
+}
+
 class SingleFile
   def initialize(path)
     @path = path
@@ -148,8 +156,9 @@ def load_grammar(path)
   end
 end
 
-def install_grammar(tmp_dir, source, all_scopes)
+def load_grammars(tmp_dir, source, all_scopes)
   is_url = source.start_with?("http:", "https:")
+  return [] if is_url && !$options[:remote]
   is_single_file = source.end_with?('.tmLanguage', '.plist')
 
   p = if !is_url
@@ -172,9 +181,7 @@ def install_grammar(tmp_dir, source, all_scopes)
 
   raise "Unsupported source: #{source}" unless p
 
-  installed = []
-
-  p.fetch(tmp_dir).each do |path|
+  p.fetch(tmp_dir).map do |path|
     grammar = load_grammar(path)
     scope = grammar['scopeName']
 
@@ -184,9 +191,17 @@ def install_grammar(tmp_dir, source, all_scopes)
       "  Previous package: #{all_scopes[scope]}"
       next
     end
-
-    File.write(File.join(GRAMMARS_PATH, "#{scope}.json"), JSON.pretty_generate(grammar))
     all_scopes[scope] = p.url
+    grammar
+  end
+end
+
+def install_grammars(grammars)
+  installed = []
+
+  grammars.each do |grammar|
+    scope = grammar['scopeName']
+    File.write(File.join(GRAMMARS_PATH, "#{scope}.json"), JSON.pretty_generate(grammar))
     installed << scope
   end
 
@@ -206,7 +221,8 @@ def run_thread(queue, all_scopes)
       dir = "#{tmpdir}/#{index}"
       Dir.mkdir(dir)
 
-      install_grammar(dir, source, all_scopes)
+      grammars = load_grammars(dir, source, all_scopes)
+      install_grammars(grammars) if $options[:install]
     end
   end
 end
@@ -232,9 +248,9 @@ def main(sources)
 
   all_scopes = {}
 
-  if ARGV[0] == '--add'
+  if $options[:add]
     Dir.mktmpdir do |tmpdir|
-      install_grammar(tmpdir, ARGV[1], all_scopes)
+      install_grammar(tmpdir, ARGV[0], all_scopes)
     end
     generate_yaml(all_scopes, sources)
   else
@@ -252,12 +268,36 @@ def main(sources)
   end
 end
 
+OptionParser.new do |opts|
+  opts.banner = "Usage: #{$0} [options]"
+
+  opts.on("--add GRAMMAR", "Add a new grammar. GRAMMAR may be a file path or URL.") do |a|
+    $options[:add] = a
+  end
+
+  opts.on("--[no-]install", "Install grammars into grammars/ directory.") do |i|
+    $options[:install] = i
+  end
+
+  opts.on("--output FILE", "Write output to FILE. Use - for stdout.") do |o|
+    $options[:output] = o == "-" ? $stdout : o
+  end
+
+  opts.on("--[no-]remote", "Download remote grammars.") do |r|
+    $options[:remote] = r
+  end
+end.parse!
+
 sources = File.open(SOURCES_FILE) do |file|
   YAML.load(file)
 end
 
 yaml = main(sources)
 
-File.write(SOURCES_FILE, YAML.dump(yaml))
+if $options[:output].is_a?(IO)
+  $options[:output].write(YAML.dump(yaml))
+else
+  File.write($options[:output], YAML.dump(yaml))
+end
 
 $stderr.puts("Done")

test/test_grammars.rb

@@ -36,4 +36,17 @@ class TestGrammars < Minitest::Test
 
     assert nonexistent_submodules.empty? && unlisted_submodules.empty?, message
   end
+
+  def test_local_scopes_are_in_sync
+    actual = YAML.load(`"#{File.join(ROOT, "script", "convert-grammars")}" --output - --no-install --no-remote 2>/dev/null`)
+    assert_predicate $?, :success?
+
+    # We're not checking remote grammars. That can take a long time and make CI
+    # flaky if network conditions are poor.
+    @grammars.delete_if { |k, v| k.start_with?("http:", "https:") }
+
+    @grammars.each do |k, v|
+      assert_equal v, actual[k], "The scopes listed for #{k} in grammars.yml don't match the scopes found in that repository"
+    end
+  end
 end