class V8::JavasriptError

Attributes

boundaries[R]
value[R]

Public Class Methods

new(try, to) click to toggle source
# File lib/v8/error.rb, line 6
    def initialize(try, to)
      @to = to
      super(initialize_unsafe(try))
    rescue Exception => e
      @boundaries = [Boundary.new(:rbframes => e.backtrace)]
      @value = e
      super("You have uncovered what is probably a BUG in therubyracer exception code. An error report would be very helpful.
JSError#initialize failed!: #{e.message}"
")
    end

Public Instance Methods

backtrace(*modifiers) click to toggle source
# File lib/v8/error.rb, line 57
def backtrace(*modifiers)
  trace_framework = modifiers.include?(:framework)
  trace_ruby = modifiers.length == 0 || modifiers.include?(:ruby)
  trace_javascript = modifiers.length == 0 || modifiers.include?(:javascript)
  mixed = []
  rbcontext = []
  jscontext = []
  @boundaries.each do |b|
    rbframes = b.rbframes.dup
    rbcontext.reverse_each do |frame|
      if frame == rbframes.last
        rbframes.pop
      else
        break
      end
    end if trace_ruby
    jsframes = b.jsframes.dup
    jscontext.reverse_each do |frame|
      if frame == jsframes.last
        jsframes.pop
      else
        break
      end
    end if trace_javascript
    rbcontext = b.rbframes
    jscontext = b.jsframes
    rbframes.reject! {|f| f =~ /lib\/v8\/.*\.rb/} unless trace_framework
    mixed.unshift(*rbframes) if trace_ruby
    mixed.unshift(*jsframes) if trace_javascript
  end
  return mixed
end
in_javascript?() click to toggle source
# File lib/v8/error.rb, line 53
def in_javascript?
  !in_ruby?
end
in_ruby?() click to toggle source
# File lib/v8/error.rb, line 49
def in_ruby?
  @value.kind_of?(Exception)
end
initialize_unsafe(try) click to toggle source
# File lib/v8/error.rb, line 18
def initialize_unsafe(try)
  message = nil
  ex = @to.rb(try.Exception())
  @boundaries = [Boundary.new(:rbframes => caller(3), :jsframes => parse_js_frames(try))]
  if V8::Object === ex
    if msg = ex['message']
      message = msg
    else
      message = ex.to_s
    end
    if cause = ex.instance_variable_get(:@native).GetHiddenValue("TheRubyRacer::Cause")
      if !cause.IsEmpty()
        prev = cause.Value()
        if prev.kind_of?(JSError)
          @boundaries.concat prev.boundaries
          @value = prev.value
        else
          @value = prev
          @boundaries.concat [Boundary.new(:rbframes => prev.backtrace)]
        end
      else
        @value = ex
      end
    end
  else
    @value = ex
    message = ex.to_s
  end
  return message
end
parse_js_frames(try) click to toggle source
# File lib/v8/error.rb, line 90
def parse_js_frames(try)
  #I can't figure out why V8 is not capturing the stacktrace here
  #in terms of StackTrace and StackFrame objects, so we have to
  #parse the string.
  raw = @to.rb(try.StackTrace())
  if raw && !raw.empty? && !syntax_error?(try)
    raw.split("\n")[1..-1].tap do |frames|
      frames.each {|frame| frame.strip!; frame.chomp!(",")}
    end.reject(&:empty?)
  else
    msg = try.Message()
    ["at #{@to.rb(msg.GetScriptResourceName())}:#{msg.GetLineNumber()}:#{msg.GetStartColumn() + 1}"]
  end
end
syntax_error?(try) click to toggle source

Syntax errors are weird in that they have a non-empty stack trace but it does not contain any source location information, so in these instances, we have to pull it out of the Message object in the TryCatch. Is there a better way to detect a syntax error

# File lib/v8/error.rb, line 109
def syntax_error?(try)
  ex = @to.rb(try.Exception())
  if ex && ex.kind_of?(V8::Object)
    type = ex["constructor"]
    type && type.kind_of?(V8::Function) && type.name == "SyntaxError"
  else
    false
  end
end