Module: MilkTea::Linter::FixEngine

Defined in:
lib/milk_tea/tooling/linter/fix_engine.rb

Constant Summary collapse

BINARY_OP_CHARS = 
%w[+ - * / % & | ^ < > = ! ? :].freeze

Class Method Summary collapse

Class Method Details

.apply_fix_edits(lines, edits) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 27

def self.apply_fix_edits(lines, edits)
  edits.sort_by { |e| [-e.start_line, -e.start_char] }.each do |edit|
    if edit.start_line == edit.end_line
      line = lines[edit.start_line]
      next unless line

      lines[edit.start_line] = +"#{line[0...edit.start_char]}#{edit.new_text}#{line[edit.end_char..]}"
    else
      prefix = (l = lines[edit.start_line]) ? l[0...edit.start_char] : ""
      suffix = (l = lines[edit.end_line]) ? l[edit.end_char..] : ""
      lines[edit.start_line..edit.end_line] = ["#{prefix}#{edit.new_text}#{suffix}"]
    end
  end
  lines
end

.edits_for_rule(code, lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 9

def self.edits_for_rule(code, lines, warning)
  case code
  when "prefer-let"             then prefer_let_edits(lines, warning)
  when "redundant-ignored-match-binding" then redundant_ignored_match_binding_edits(lines, warning)
  when "prefer-let-else"        then prefer_let_else_edits(lines, warning)
  when "prefer-var-else"        then prefer_var_else_edits(lines, warning)
  when "redundant-bool-compare" then redundant_bool_compare_edits(lines, warning)
  when "redundant-cast"        then redundant_cast_edits(lines, warning)
  when "redundant-else"         then redundant_else_edits(lines, warning)
  when "redundant-return"       then redundant_return_edits(lines, warning)
  when "redundant-type-annotation" then redundant_type_annotation_edits(lines, warning)
  when "prefer-inline-methods"  then prefer_inline_methods_edits(lines, warning)
  when "unused-import"          then unused_import_edits(lines, warning)
  when "trailing-list-comma"    then trailing_list_comma_edits(lines, warning)
  else []
  end
end

.edits_to_lsp_text_edits(edits, uri) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 43

def self.edits_to_lsp_text_edits(edits, uri)
  edits.map do |edit|
    {
      range: {
        start: { line: edit.start_line, character: edit.start_char },
        end:   { line: edit.end_line,   character: edit.end_char },
      },
      newText: edit.new_text,
    }
  end
end

.inner_has_top_level_operators?(inner) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 318

def self.inner_has_top_level_operators?(inner)
  depth = 0
  i = 0
  while i < inner.length
    case inner[i]
    when "(", "[", "{"
      depth += 1
    when ")", "]", "}"
      depth -= 1 if depth > 0
    when *BINARY_OP_CHARS
      if depth == 0 && (inner[i] == "-" || inner[i] == "~") && start_of_expression?(inner, i)
        i += 1
        next
      end
      return true if depth == 0
    end
    i += 1
  end
  false
end

.match_paren(line, open_pos) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 305

def self.match_paren(line, open_pos)
  depth = 0
  (open_pos...line.length).each do |i|
    case line[i]
    when "(" then depth += 1
    when ")" then depth -= 1; return i if depth == 0
    end
  end
  nil
end

.prefer_inline_methods_edits(lines, warning) ⇒ Object

Moves the methods of an extending X: block inline into the matching struct X: declaration. Only rewrites when the struct immediately precedes the extending block (blank lines allowed between them); other layouts are left alone since the move would be non-local.



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 160

def self.prefer_inline_methods_edits(lines, warning)
  name = warning.symbol_name
  return [] unless name && warning.line

  struct_idx = lines.index { |l| l.match?(/\A\s*struct\s+#{Regexp.escape(name)}\b/) }
  return [] unless struct_idx

  last_member_idx = nil
  ((struct_idx + 1)...lines.length).each do |i|
    l = lines[i]
    break if !l.chomp.empty? && !l.start_with?(" ", "\t")

    last_member_idx = i unless l.chomp.empty?
  end
  return [] unless last_member_idx

  ext_start_idx = warning.line - 1
  return [] unless last_member_idx < ext_start_idx

  ext_end_idx = ext_start_idx
  ((ext_start_idx + 1)...lines.length).each do |i|
    l = lines[i]
    break if !l.chomp.empty? && !l.start_with?(" ", "\t")

    ext_end_idx = i unless l.chomp.empty?
  end

  method_lines = lines[(ext_start_idx + 1)..ext_end_idx].to_a
  method_lines.shift while method_lines.first && method_lines.first.chomp.empty?
  method_lines.pop while method_lines.last && method_lines.last.chomp.empty?
  return [] if method_lines.empty?

  between = lines[(last_member_idx + 1)...ext_start_idx]
  return [] unless between.all? { |l| l.chomp.empty? }

  method_text = method_lines.join
  new_text = "#{lines[last_member_idx].chomp}\n\n#{method_text}"

  [FixEdit.new(start_line: last_member_idx, start_char: 0, end_line: ext_end_idx + 1, end_char: 0, new_text: new_text)]
end

.prefer_let_edits(lines, warning) ⇒ Object

── per-rule edit generators ──────────────────────────────────────────



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 57

def self.prefer_let_edits(lines, warning)
  return [] unless warning.line

  line_idx = warning.line - 1
  original = lines[line_idx]
  return [] unless original&.match?(/\bvar\b/)

  new_line = original.sub(/\bvar\b/, "let")
  [FixEdit.new(start_line: line_idx, start_char: 0, end_line: line_idx + 1, end_char: 0, new_text: new_line)]
end

.prefer_let_else_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 81

def self.prefer_let_else_edits(lines, warning)
  return [] unless warning.line

  fix = Linter.build_prefer_let_else_fix(lines, warning.line - 1, symbol_name: warning.symbol_name)
  return [] unless fix

  [FixEdit.new(start_line: fix[:start_line_idx], start_char: 0, end_line: fix[:end_line_idx] + 1, end_char: 0, new_text: fix[:new_text])]
end

.prefer_var_else_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 90

def self.prefer_var_else_edits(lines, warning)
  prefer_let_else_edits(lines, warning)
end

.redundant_bool_compare_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 94

def self.redundant_bool_compare_edits(lines, warning)
  return [] unless warning.line && warning.column && warning.length

  line_idx = warning.line - 1
  line = lines[line_idx]
  return [] unless line

  start_char = warning.column - 1
  end_char = start_char + warning.length
  return [] if start_char.negative? || end_char > line.length

  expr_text = line[start_char...end_char]
  replacement = Linter.redundant_bool_compare_replacement(expr_text)
  return [] unless replacement

  [FixEdit.new(start_line: line_idx, start_char:, end_line: line_idx, end_char:, new_text: replacement)]
end

.redundant_cast_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 246

def self.redundant_cast_edits(lines, warning)
  return [] unless warning.line && warning.column

  line_idx = warning.line - 1
  line = lines[line_idx]
  return [] unless line

  start = warning.column - 1
  return [] unless start >= 0 && start < line.length

  arrow = line.index("<-", start)
  return [] unless arrow

  type_ref = line[start...arrow]
  return [] unless type_ref.match?(/\A[A-Za-z_][A-Za-z0-9_\[\]\.,\s@]*\z/)

  arrow_end = arrow + 2

  # When only the parentheses are redundant (the cast itself is still
  # needed), remove just the `(` and matching `)`.
  if warning.message&.include?("parentheses")
    return [] unless arrow_end < line.length && line[arrow_end] == "("

    open_paren = arrow_end
    close_paren = match_paren(line, open_paren)
    return [] unless close_paren

    return [FixEdit.new(start_line: line_idx, start_char: open_paren, end_line: line_idx, end_char: open_paren + 1, new_text: ""),
            FixEdit.new(start_line: line_idx, start_char: close_paren, end_line: line_idx, end_char: close_paren + 1, new_text: "")]
  end

  # Cast to same type / own->ptr / widening are redundant — remove the
  # `TargetType<-` prefix. When the inner expression is then left
  # parenthesized with no operators, also strip the orphaned parens.
  new_start = start

  # When the cast is inside an `unsafe:` expression, also remove the
  # `unsafe: ` wrapper.
  unsafe_keyword = line.rindex("unsafe:", new_start)
  if unsafe_keyword
    prefix = line[unsafe_keyword...new_start]
    if prefix.match?(/\Aunsafe:\s*\z/)
      new_start = unsafe_keyword
    end
  end

  edits = [FixEdit.new(start_line: line_idx, start_char: new_start, end_line: line_idx, end_char: arrow_end, new_text: "")]

  if arrow_end < line.length && line[arrow_end] == "("
    close_paren = match_paren(line, arrow_end)
    if close_paren && !inner_has_top_level_operators?(line[arrow_end + 1...close_paren])
      edits << FixEdit.new(start_line: line_idx, start_char: arrow_end, end_line: line_idx, end_char: arrow_end + 1, new_text: "")
      edits << FixEdit.new(start_line: line_idx, start_char: close_paren, end_line: line_idx, end_char: close_paren + 1, new_text: "")
    end
  end

  edits
end

.redundant_else_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 112

def self.redundant_else_edits(lines, warning)
  return [] unless warning.line

  diag_idx = warning.line - 1
  return [] if diag_idx.negative?

  if lines[diag_idx]&.match?(/\A\s*else:\s*\z/)
    else_idx = diag_idx
    first_body_idx = else_idx + 1
  else
    first_body_idx = diag_idx
    return [] if first_body_idx < 1

    else_idx = (0...first_body_idx).to_a.reverse.find { |i| lines[i]&.match?(/\A\s*else:\s*\z/) }
  end
  return [] unless else_idx
  return [] if first_body_idx >= lines.length

  else_indent = lines[else_idx].match(/\A(\s*)/)[1]
  body_indent = "#{else_indent}    "

  body_end_idx = first_body_idx
  (first_body_idx...lines.length).each do |i|
    l = lines[i]
    if l.chomp.empty? || l.start_with?(body_indent)
      body_end_idx = i
    else
      break
    end
  end

  new_body = lines[first_body_idx..body_end_idx].map { |l| l.sub(/\A    /, "") }.join
  [FixEdit.new(start_line: else_idx, start_char: 0, end_line: body_end_idx + 1, end_char: 0, new_text: new_body)]
end

.redundant_ignored_match_binding_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 68

def self.redundant_ignored_match_binding_edits(lines, warning)
  return [] unless warning.line && warning.column

  line_idx = warning.line - 1
  line = lines[line_idx]
  return [] unless line

  span = Linter.redundant_ignored_match_binding_span(line, column: warning.column)
  return [] unless span

  [FixEdit.new(start_line: line_idx, start_char: span[:start_char], end_line: line_idx, end_char: span[:end_char], new_text: "")]
end

.redundant_return_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 147

def self.redundant_return_edits(lines, warning)
  return [] unless warning.line

  line_idx = warning.line - 1
  return [] unless lines[line_idx]&.match?(/\A\s*return\s*\z/)

  [FixEdit.new(start_line: line_idx, start_char: 0, end_line: line_idx + 1, end_char: 0, new_text: "")]
end

.redundant_type_annotation_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 224

def self.redundant_type_annotation_edits(lines, warning)
  return [] unless warning.line

  line_idx = warning.line - 1
  line = lines[line_idx]
  return [] unless line

  name_len = warning.length
  col = warning.column - 1
  return [] if col.negative? || col + name_len > line.length

  after_name = col + name_len
  rest = line[after_name..]
  return [] unless rest

  type_match = rest.match(/\s*:\s*\S+/)
  return [] unless type_match

  new_line = +"#{line[0...after_name]}#{rest[type_match.end(0)..]}"
  [FixEdit.new(start_line: line_idx, start_char: 0, end_line: line_idx + 1, end_char: 0, new_text: new_line)]
end

.start_of_expression?(inner, pos) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 339

def self.start_of_expression?(inner, pos)
  return true if pos == 0
  prev = pos - 1
  prev >= 0 && (inner[prev] == " " || inner[prev] == "\t" || inner[prev] == "(")
end

.trailing_list_comma_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 210

def self.trailing_list_comma_edits(lines, warning)
  return [] unless warning.line && warning.column

  line_idx = warning.line - 1
  line = lines[line_idx]
  return [] unless line

  char_idx = warning.column - 1
  return [] if char_idx.negative? || char_idx >= line.length
  return [] unless line[char_idx] == ","

  [FixEdit.new(start_line: line_idx, start_char: char_idx, end_line: line_idx, end_char: char_idx + 1, new_text: "")]
end

.unused_import_edits(lines, warning) ⇒ Object 



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# File 'lib/milk_tea/tooling/linter/fix_engine.rb', line 201

def self.unused_import_edits(lines, warning)
  return [] unless warning.line

  line_idx = warning.line - 1
  return [] unless lines[line_idx]&.match?(/\A\s*import\b/)

  [FixEdit.new(start_line: line_idx, start_char: 0, end_line: line_idx + 1, end_char: 0, new_text: "")]
end