Improve fatal error handling.

- Move JS/CSS parsing error handling up to the level where we read the
  file in, so when IO error occours we'll also catch that.

- Handle guide reading/formatting errors.

- Handle errors in formatting class docs (wasn't able to test it, but
  a user reported a stack trace with encoding error happening inside
  there - maybe a difference when running in Windows).

lib/jsduck/app.rb

@@ -104,7 +104,12 @@ def run
     def parallel_parse(filenames)
       @parallel.map(filenames) do |fname|
         Logger.instance.log("Parsing", fname)
-        SourceFile.new(JsDuck::IO.read(fname), fname, @opts)
+        begin
+          SourceFile.new(JsDuck::IO.read(fname), fname, @opts)
+        rescue
+          Logger.instance.fatal("Error while parsing #{fname}", $!)
+          exit(1)
+        end
       end
     end
 
@@ -159,10 +164,15 @@ def format_classes
       # Format all doc-objects in parallel
       formatted_classes = @parallel.map(@relations.classes) do |cls|
         Logger.instance.log("Markdown formatting #{cls[:name]}")
-        {
-          :doc => class_formatter.format(cls.internal_doc),
-          :images => doc_formatter.images
-        }
+        begin
+          {
+            :doc => class_formatter.format(cls.internal_doc),
+            :images => doc_formatter.images
+          }
+        rescue
+          Logger.instance.fatal("Error while formatting #{cls[:name]}", $!)
+          exit(1)
+        end
       end
       # Then merge the data back to classes sequentially
       formatted_classes.each do |cls|

lib/jsduck/guides.rb

@@ -59,16 +59,22 @@ def to_array
 
     def load_guide(guide)
       in_dir = @path + "/guides/" + guide["name"]
-      return Logger.instance.warn(:guide, "Guide #{in_dir} not found") unless File.exists?(in_dir)
 
-      guide_file = in_dir + "/README.md"
-      return Logger.instance.warn(:guide, "README.md not found in #{in_dir}") unless File.exists?(guide_file)
+      begin
+        return Logger.instance.warn(:guide, "Guide #{in_dir} not found") unless File.exists?(in_dir)
 
-      @formatter.doc_context = {:filename => guide_file, :linenr => 0}
-      name = File.basename(in_dir)
-      @formatter.img_path = "guides/#{name}"
+        guide_file = in_dir + "/README.md"
+        return Logger.instance.warn(:guide, "README.md not found in #{in_dir}") unless File.exists?(guide_file)
 
-      return add_toc(guide, @formatter.format(JsDuck::IO.read(guide_file)))
+        @formatter.doc_context = {:filename => guide_file, :linenr => 0}
+        name = File.basename(in_dir)
+        @formatter.img_path = "guides/#{name}"
+
+        return add_toc(guide, @formatter.format(JsDuck::IO.read(guide_file)))
+      rescue
+        Logger.instance.fatal("Error while reading/formatting guide #{in_dir}", $!)
+        exit(1)
+      end
     end
 
     def write_guide(guide, dir)

lib/jsduck/logger.rb

@@ -114,6 +114,15 @@ def format(filename=nil, line=nil)
       end
       out
     end
+
+    # Prints fatal error message with backtrace.
+    # The error param should be $! from resque block.
+    def fatal(msg, error)
+      puts "#{msg}: #{error}"
+      puts
+      puts "Here's a full backtrace:"
+      puts error.backtrace
+    end
   end
 
 end

lib/jsduck/source_file.rb

@@ -80,18 +80,10 @@ def id(doc)
 
     # Parses the file depending on filename as JS or CSS
     def parse
-      begin
-        if @filename =~ /\.s?css$/
-          CssParser.new(@contents, @options).parse
-        else
-          JsParser.new(@contents, @options).parse
-        end
-      rescue
-        puts "Error while parsing #{@filename}: #{$!}"
-        puts
-        puts "Here's a full backtrace:"
-        puts $!.backtrace
-        exit(1)
+      if @filename =~ /\.s?css$/
+        CssParser.new(@contents, @options).parse
+      else
+        JsParser.new(@contents, @options).parse
       end
     end