Exception: Parsby::ExpectationFailed

Inherits:
Error
  • Object
show all
Defined in:
lib/parsby.rb

Constant Summary collapse

INDENTATION = 
2

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctx) ⇒ ExpectationFailed

Initializes an ExpectationFailed from a backed_io and an optional expectation with which to start the list of expectations that lead to this failure.



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# File 'lib/parsby.rb', line 288

def initialize(ctx)
  @ctx = ctx
end

Instance Attribute Details

#ctx ⇒ Object (readonly)

Returns the value of attribute ctx.



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# File 'lib/parsby.rb', line 283

def ctx
  @ctx
end

Instance Method Details

#failure_tree ⇒ Object 



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# File 'lib/parsby.rb', line 297

def failure_tree
  @failure_tree ||= begin
    other_ranges = ctx.parsed_ranges.flatten.select do |range|
      range.start == parsed_range.start && range != parsed_range
    end
    relevant_paths = [parsed_range, *other_ranges].map(&:path)
    parsed_range.dup.root.trim_to_just!(*relevant_paths) do |c, i, max_sibling|
      c.failed && i != max_sibling && c.start != parsed_range.start
    end
  end
end

#hunk_at(pos) ⇒ Object 



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# File 'lib/parsby.rb', line 362

def hunk_at(pos)
  ctx.bio.with_saved_pos do
    ctx.bio.seek pos
    hunk_prelude + hunk_graph
  end
end

#hunk_graph ⇒ Object 



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# File 'lib/parsby.rb', line 320

def hunk_graph
  line_range = ctx.bio.current_line_range
  line_length = ctx.bio.current_line.length
  tree_lines = []
  max_tree_slice_length = failure_tree.flatten.map {|t| t.right_tree_slice.length }.max
  prev_slice_length = nil
  failure_tree.each do |range|
    line = ""
    line << " " * INDENTATION
    line << range.underline(line_range)
    line << " " * (line_length + INDENTATION - line.length)
    this_slice_length = range.right_tree_slice.length
    # If previous slice was a parent with multiple children (current
    # slice being the first child), we'll want to draw the forking
    # line.
    if prev_slice_length && this_slice_length > prev_slice_length
      # Current line already has the correct width to start drawing the
      # tree. Copy it and substitute the rendered range with spaces.
      fork_line = line.gsub(/./, " ")
      fork_line << " "
      i = 0
      fork_line << range.right_tree_slice.rjust(max_tree_slice_length).gsub(/[*|]/) do |c|
        i += 1
        if i <= this_slice_length - prev_slice_length
          "\\"
        else
          c 
        end
      end
      fork_line << "\n"
    else
      fork_line = ""
    end
    prev_slice_length = this_slice_length
    line << " #{range.right_tree_slice.rjust(max_tree_slice_length)}"
    line << " #{range.failed ? "failure" : "success"}: #{range.label}"
    line << "\n"
    tree_lines << fork_line << line
  end
  tree_lines.reverse.join
end

#hunk_prelude ⇒ Object 



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# File 'lib/parsby.rb', line 313

def hunk_prelude
  <<~EOF
    line #{ctx.bio.line_number}:
    #{" " * INDENTATION}#{ctx.bio.current_line}
  EOF
end

#message ⇒ Object

The message of the exception. It’s the current line, with a kind-of backtrace showing the failed expectations with a visualization of their range in the current line.



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# File 'lib/parsby.rb', line 372

def message
  hunk_at parsed_range.start
end

#message_hunk(failure_tree) ⇒ Object 



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# File 'lib/parsby.rb', line 294

def message_hunk(failure_tree)
end

#parsed_range ⇒ Object 



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# File 'lib/parsby.rb', line 309

def parsed_range
  @parsed_range ||= ctx.furthest_parsed_range
end