Merge pull request #1001 from nanoc/less-fiber

Run less filter on main fiber

lib/nanoc/base/compilation/compiler.rb

@@ -233,9 +233,14 @@ def compile_rep(rep)
         Nanoc::Int::NotificationCenter.post(:compilation_started, rep)
         res = fiber.resume
 
-        if res.is_a?(Nanoc::Int::Errors::UnmetDependency)
+        case res
+        when Nanoc::Int::Errors::UnmetDependency
           Nanoc::Int::NotificationCenter.post(:compilation_suspended, rep, res)
           raise(res)
+        when Proc
+          fiber.resume(res.call)
+        else
+          # TODO: raise
         end
       end
 

lib/nanoc/base/services/filter.rb

@@ -184,6 +184,11 @@ def filename
       end
     end
 
+    # @api private
+    def on_main_fiber(&block)
+      Fiber.yield(block)
+    end
+
     # Creates a dependency from the item that is currently being filtered onto
     # the given collection of items. In other words, require the given items
     # to be compiled first before this items is processed.

lib/nanoc/filters/less.rb

@@ -43,8 +43,10 @@ def run(content, params = {})
 
       # Add filename to load path
       paths = [File.dirname(@item[:content_filename])]
-      parser = ::Less::Parser.new(paths: paths)
-      parser.parse(content).to_css params
+      on_main_fiber do
+        parser = ::Less::Parser.new(paths: paths)
+        parser.parse(content).to_css(params)
+      end
     end
   end
 end

spec/nanoc/filters/less_spec.rb

@@ -1,37 +1,106 @@
 describe Nanoc::Filters::Less, site: true, stdio: true do
-  before do
-    File.write('content/a.less', '@import "b.less";')
-    File.write('content/b.less', 'p { color: red; }')
+  # These tests are high-level in order to interact well with the compiler. This is important for
+  # this :less filter, because of the way it handles fibers.
 
+  before do
     File.open('Rules', 'w') do |io|
-      io.write "compile '/a.less' do\n"
-      io.write "  filter :less\n"
-      io.write "  write '/a.css'\n"
-      io.write "end\n"
-      io.write "\n"
-      io.write "compile '/b.less' do\n"
+      io.write "compile '/**/*.less' do\n"
       io.write "  filter :less\n"
+      io.write "  write item.identifier.without_ext + '.css'\n"
       io.write "end\n"
     end
   end
 
-  it 'compiles a.less' do
-    skip 'flaky test'
+  context 'one file' do
+    let(:content_a) { 'p { color: red; }' }
+
+    before do
+      File.write('content/a.less', content_a)
+    end
+
+    it 'compiles a.less' do
+      Nanoc::CLI.run(%w(compile))
+      expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*red;?\s*\}/)
+    end
+
+    context 'with compression' do
+      let(:content_a) { '.foo { bar: a; } .bar { foo: b; }' }
+
+      before do
+        File.open('Rules', 'w') do |io|
+          io.write "compile '/*.less' do\n"
+          io.write "  filter :less, compress: true\n"
+          io.write "  write item.identifier.without_ext + '.css'\n"
+          io.write "end\n"
+        end
+      end
+
+      it 'compiles and compresses a.less' do
+        Nanoc::CLI.run(%w(compile))
+        expect(File.read('output/a.css')).to match(/^\.foo\{bar:a\}\n?\.bar\{foo:b\}/)
+      end
+    end
+  end
+
+  context 'two files' do
+    let(:content_a) { '@import "b.less";' }
+    let(:content_b) { 'p { color: red; }' }
+
+    before do
+      File.write('content/a.less', content_a)
+      File.write('content/b.less', content_b)
+    end
+
+    it 'compiles a.less' do
+      Nanoc::CLI.run(%w(compile))
+      expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*red;?\s*\}/)
+    end
+
+    it 'recompiles a.less if b.less has changed' do
+      Nanoc::CLI.run(%w(compile))
+
+      File.write('content/b.less', 'p { color: blue; }')
+
+      Nanoc::CLI.run(%w(compile))
+      expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*blue;?\s*\}/)
+    end
+  end
+
+  context 'paths relative to site directory' do
+    let(:content_a) { '@import "content/foo/bar/imported_file.less";' }
+    let(:content_b) { 'p { color: red; }' }
 
-    Nanoc::CLI.run(%w(compile))
-    expect(Dir['output/*']).to eql(['output/a.css'])
-    expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*red;?\s*\}/)
+    before do
+      FileUtils.mkdir_p('content/foo/bar')
+
+      File.write('content/a.less', content_a)
+      File.write('content/foo/bar/imported_file.less', content_b)
+    end
+
+    it 'compiles a.less' do
+      Nanoc::CLI.run(%w(compile))
+      expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*red;?\s*\}/)
+    end
+
+    it 'recompiles a.less if b.less has changed'
   end
 
-  it 'recompiles a.less if b.less has changed' do
-    skip 'flaky test'
+  context 'paths relative to current file' do
+    let(:content_a) { '@import "bar/imported_file.less";' }
+    let(:content_b) { 'p { color: red; }' }
+
+    before do
+      FileUtils.mkdir_p('content/foo/bar')
 
-    Nanoc::CLI.run(%w(compile))
+      File.write('content/foo/a.less', content_a)
+      File.write('content/foo/bar/imported_file.less', content_b)
+    end
 
-    File.write('content/b.less', 'p { color: blue; }')
+    it 'compiles a.less' do
+      Nanoc::CLI.run(%w(compile))
+      expect(File.read('output/foo/a.css')).to match(/^p\s*\{\s*color:\s*red;?\s*\}/)
+    end
 
-    Nanoc::CLI.run(%w(compile))
-    expect(Dir['output/*']).to eql(['output/a.css'])
-    expect(File.read('output/a.css')).to match(/^p\s*\{\s*color:\s*blue;?\s*\}/)
+    it 'recompiles a.less if b.less has changed'
   end
 end