Class: Prism::Merge::ScaffoldChunkRemover

Inherits:
Object
  • Object
show all
Defined in:
lib/prism/merge/scaffold_chunk_remover.rb

Overview

Surgically removes bundle-gem scaffold boilerplate from Rakefiles.

Each ChunkSpec describes an anchor (exact require/task call) and optional satellite nodes (matched fuzzily via Jaccard similarity). The remover finds all matching nodes in the top-level statements and removes them by line range, leaving user-added content intact.

Examples:

specs = [ScaffoldChunkRemover::RSPEC_SPEC, ScaffoldChunkRemover::RUBOCOP_SPEC]
clean = ScaffoldChunkRemover.remove(source, specs)

Constant Summary collapse

ChunkSpec = 
Ruby::Merge::ScaffoldChunkSupport::ChunkSpec
BUNDLER_GEM_TASKS_SPEC = 
Ruby::Merge::ScaffoldChunkSupport::BUNDLER_GEM_TASKS_SPEC
RSPEC_SPEC = 
Ruby::Merge::ScaffoldChunkSupport::RSPEC_SPEC
RUBOCOP_SPEC = 
Ruby::Merge::ScaffoldChunkSupport::RUBOCOP_SPEC
DEFAULT_TASK_SPEC = 
Ruby::Merge::ScaffoldChunkSupport::DEFAULT_TASK_SPEC
ALL_SPECS = 
Ruby::Merge::ScaffoldChunkSupport::ALL_SPECS

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source, specs = ALL_SPECS) ⇒ ScaffoldChunkRemover

Returns a new instance of ScaffoldChunkRemover.



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# File 'lib/prism/merge/scaffold_chunk_remover.rb', line 29

def initialize(source, specs = ALL_SPECS)
  @source = source
  @specs = specs
end

Class Method Details

.remove(source, specs = ALL_SPECS) ⇒ Object 



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# File 'lib/prism/merge/scaffold_chunk_remover.rb', line 24

def remove(source, specs = ALL_SPECS)
  new(source, specs).call
end

Instance Method Details

#call ⇒ Object 



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# File 'lib/prism/merge/scaffold_chunk_remover.rb', line 34

def call
  return @source if @source.empty?

  parse_result = TreeHaver.with_backend(Prism::Merge::BACKEND_REFERENCE.id) do
    TreeHaver.parser_for(:ruby, backend_type: :prism).parse(@source).parse_result
  end
  statements = parse_result.value.statements&.body&.compact || []
  return @source if statements.empty?

  lines_to_remove = Set.new

  @specs.each do |spec|
    anchor_idx = find_anchor(statements, spec)
    next unless anchor_idx

    nodes_to_remove = [statements[anchor_idx]]

    if spec.satellite_patterns.any?
      start_idx = [0, anchor_idx - spec.max_lookbehind].max
      end_idx = [statements.size - 1, anchor_idx + spec.max_lookahead].min

      spec.satellite_patterns.each do |pattern|
        p_tokens = Ruby::Merge::ScaffoldChunkSupport.jaccard_tokens(pattern)
        (start_idx..end_idx).each do |i|
          next if i == anchor_idx

          candidate = statements[i]
          c_tokens = Ruby::Merge::ScaffoldChunkSupport.jaccard_tokens(candidate.slice.to_s)
          score = Ruby::Merge::ScaffoldChunkSupport.jaccard(p_tokens, c_tokens)
          nodes_to_remove << candidate if score >= spec.jaccard_threshold
        end
      end
    end

    nodes_to_remove.each do |node|
      (node.location.start_line..node.location.end_line).each { |ln| lines_to_remove << ln }
    end
  end

  return @source if lines_to_remove.empty?

  lines = @source.lines

  # Remove up to 1 trailing blank line per contiguous removed block
  trailing = Set.new
  lines_to_remove.to_a.sort.each do |ln|
    next if lines_to_remove.include?(ln + 1)

    next_line = lines[ln] # 0-indexed: lines[ln] is line number ln+1
    trailing << (ln + 1) if next_line && next_line.strip.empty?
  end
  lines_to_remove.merge(trailing)

  lines.reject.with_index { |_, i| lines_to_remove.include?(i + 1) }.join
end