Class: Chef::Formatters::ErrorInspectors::CompileErrorInspector

Inherits:
Object
  • Object
show all
Defined in:
lib/chef/formatters/error_inspectors/compile_error_inspector.rb

Overview

CompileErrorInspector

Wraps exceptions that occur during the compile phase of a Chef run and tries to find the code responsible for the error.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, exception) ⇒ CompileErrorInspector

Returns a new instance of CompileErrorInspector.



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 31

def initialize(path, exception)
  @path, @exception = path, exception
  @backtrace_lines_in_cookbooks = nil
  @file_lines = nil
  @culprit_backtrace_entry = nil
  @culprit_line = nil
end

Instance Attribute Details

#exception ⇒ Object (readonly)

Returns the value of attribute exception.



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 29

def exception
  @exception
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 28

def path
  @path
end

Instance Method Details

#add_explanation(error_description) ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 39

def add_explanation(error_description)
  error_description.section(exception.class.name, exception.message)

  if found_error_in_cookbooks?
    traceback = filtered_bt.map { |line| "  #{line}" }.join("\n")
    error_description.section("Cookbook Trace: (most recent call first)", traceback)
    error_description.section("Relevant File Content:", context)
  end

  if exception_message_modifying_frozen?
    msg = <<-MESSAGE
    Ruby objects are often frozen to prevent further modifications
    when they would negatively impact the process (e.g. values inside
    Ruby's ENV class) or to prevent polluting other objects when default
    values are passed by reference to many instances of an object (e.g.
    the empty Array as a Chef resource default, passed by reference
    to every instance of the resource).

    Chef uses Object#freeze to ensure the default values of properties
    inside Chef resources are not modified, so that when a new instance
    of a Chef resource is created, and Object#dup copies values by
    reference, the new resource is not receiving a default value that
    has been by a previous instance of that resource.

    Instead of modifying an object that contains a default value for all
    instances of a Chef resource, create a new object and assign it to
    the resource's parameter, e.g.:

    fruit_basket = resource(:fruit_basket, 'default')

    # BAD: modifies 'contents' object for all new fruit_basket instances
    fruit_basket.contents << 'apple'

    # GOOD: allocates new array only owned by this fruit_basket instance
    fruit_basket.contents %w(apple)

    MESSAGE

    error_description.section("Additional information:", msg.gsub(/^ {6}/, ""))
  end
end

#backtrace_lines_in_cookbooks ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 136

def backtrace_lines_in_cookbooks
  @backtrace_lines_in_cookbooks ||=
    begin
      filters = Array(Chef::Config.cookbook_path).map { |p| /^#{Regexp.escape(p)}/i }
      r = exception.backtrace.select { |line| filters.any? { |filter| line =~ filter } }
      Chef::Log.trace("Filtered backtrace of compile error: #{r.join(",")}")
      r
    end
end

#context ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 81

def context
  context_lines = []
  context_lines << "#{culprit_file}:\n\n"
  Range.new(display_lower_bound, display_upper_bound).each do |i|
    line_nr = (i + 1).to_s.rjust(3)
    indicator = (i + 1) == culprit_line ? ">> " : ":  "
    context_lines << "#{line_nr}#{indicator}#{file_lines[i]}"
  end
  context_lines.join("")
end

#culprit_backtrace_entry ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 108

def culprit_backtrace_entry
  @culprit_backtrace_entry ||= begin
    bt_entry = filtered_bt.first
    Chef::Log.trace("Backtrace entry for compile error: '#{bt_entry}'")
    bt_entry
  end
end

#culprit_file ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 124

def culprit_file
  @culprit_file ||= culprit_backtrace_entry[/^((?:.\:)?[^:]+):(\d+)/, 1]
end

#culprit_line ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 116

def culprit_line
  @culprit_line ||= begin
    line_number = culprit_backtrace_entry[/^(?:.\:)?[^:]+:(\d+)/, 1].to_i
    Chef::Log.trace("Line number of compile error: '#{line_number}'")
    line_number
  end
end

#display_lower_bound ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 92

def display_lower_bound
  lower = (culprit_line - 8)
  lower = 0 if lower < 0
  lower
end

#display_upper_bound ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 98

def display_upper_bound
  upper = (culprit_line + 8)
  upper = file_lines.size if upper > file_lines.size
  upper
end

#exception_message_modifying_frozen? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 146

def exception_message_modifying_frozen?
  exception.message.include?("can't modify frozen")
end

#file_lines ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 104

def file_lines
  @file_lines ||= IO.readlines(culprit_file)
end

#filtered_bt ⇒ Object 



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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 128

def filtered_bt
  backtrace_lines_in_cookbooks.count > 0 ? backtrace_lines_in_cookbooks : exception.backtrace
end

#found_error_in_cookbooks? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef/formatters/error_inspectors/compile_error_inspector.rb', line 132

def found_error_in_cookbooks?
  !backtrace_lines_in_cookbooks.empty?
end