class RSpec::Core::Formatters::SnippetExtractor

@api private

Extracts code snippets by looking at the backtrace of the passed error and applies synax highlighting and line numbers using html.

Public Instance Methods

lines_around(file, line) click to toggle source

@api private

Extract lines of code centered around a particular line within a source file.

@param [String] file filename @param [Fixnum] line line number @return [String] lines around the target line within the file (2 above and 1 below).

# File lib/rspec/core/formatters/snippet_extractor.rb, line 57
def lines_around(file, line)
  if File.file?(file)
    lines = File.read(file).split("\n")
    min = [0, line-3].max
    max = [line+1, lines.length-1].min
    selected_lines = []
    selected_lines.join("\n")
    lines[min..max].join("\n")
  else
    "# Couldn't get snippet for #{file}"
  end
rescue SecurityError
  "# Couldn't get snippet for #{file}"
end
post_process(highlighted, offending_line) click to toggle source

@api private

Adds line numbers to all lines and highlights the line where the failure occurred using html `span` tags.

@param [String] highlighted syntax-highlighted snippet surrounding the offending line of code @param [Fixnum] offending_line line where failure occured @return [String] completed snippet

# File lib/rspec/core/formatters/snippet_extractor.rb, line 79
def post_process(highlighted, offending_line)
  new_lines = []
  highlighted.split("\n").each_with_index do |line, i|
    new_line = "<span class=\"linenum\">#{offending_line+i-2}</span>#{line}"
    new_line = "<span class=\"offending\">#{new_line}</span>" if i == 2
    new_lines << new_line
  end
  new_lines.join("\n")
end
snippet(backtrace) click to toggle source

@api private

Extract lines of code corresponding to a backtrace.

@param [String] backtrace the backtrace from a test failure @return [String] highlighted code snippet indicating where the test failure occured

@see post_process

# File lib/rspec/core/formatters/snippet_extractor.rb, line 25
def snippet(backtrace)
  raw_code, line = snippet_for(backtrace[0])
  highlighted = @@converter.convert(raw_code, false)
  highlighted << "\n<span class=\"comment\"># gem install syntax to get syntax highlighting</span>" if @@converter.is_a?(NullConverter)
  post_process(highlighted, line)
end
snippet_for(error_line) click to toggle source

@api private

Create a snippet from a line of code.

@param [String] error_line file name with line number (i.e. 'foo_spec.rb:12') @return [String] lines around the target line within the file

@see lines_around

# File lib/rspec/core/formatters/snippet_extractor.rb, line 40
def snippet_for(error_line)
  if error_line =~ /(.*):(\d+)/
    file = $1
    line = $2.to_i
    [lines_around(file, line), line]
  else
    ["# Couldn't get snippet for #{error_line}", 1]
  end
end