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(MAINT) Rubocop fixes for lexer
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@chelnak
chelnak committed Oct 5, 2022
1 parent 1d412f0 commit d429387
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278 changes: 138 additions & 140 deletions lib/puppet-lint/lexer/string_slurper.rb
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Original file line number Diff line number Diff line change
@@ -1,173 +1,171 @@
require 'strscan'

class PuppetLint
class Lexer
# Document this
# TODO
class StringSlurper
class UnterminatedStringError < StandardError; end

attr_accessor :scanner
attr_accessor :results
attr_accessor :interp_stack

START_INTERP_PATTERN = %r{\$\{}.freeze
END_INTERP_PATTERN = %r{\}}.freeze
END_STRING_PATTERN = %r{(\A|[^\\])(\\\\)*"}.freeze
UNENC_VAR_PATTERN = %r{(\A|[^\\])\$(::)?(\w+(-\w+)*::)*\w+(-\w+)*}.freeze
ESC_DQUOTE_PATTERN = %r{\\+"}.freeze
LBRACE_PATTERN = %r{\{}.freeze

def initialize(string)
@scanner = StringScanner.new(string)
@results = []
@interp_stack = []
@segment = []
end

def parse
@segment_type = :STRING

until scanner.eos?
if scanner.match?(START_INTERP_PATTERN)
start_interp
elsif !interp_stack.empty? && scanner.match?(LBRACE_PATTERN)
read_char
elsif scanner.match?(END_INTERP_PATTERN)
end_interp
elsif unenclosed_variable?
unenclosed_variable
elsif scanner.match?(END_STRING_PATTERN)
end_string
break if interp_stack.empty?
elsif scanner.match?(ESC_DQUOTE_PATTERN)
@segment << scanner.scan(ESC_DQUOTE_PATTERN)
else
read_char
end
end
class PuppetLint::Lexer
# Internal: A class for slurping strings from a Puppet manifest.
class StringSlurper
attr_accessor :scanner
attr_accessor :results
attr_accessor :interp_stack

START_INTERP_PATTERN = %r{\$\{}.freeze
END_INTERP_PATTERN = %r{\}}.freeze
END_STRING_PATTERN = %r{(\A|[^\\])(\\\\)*"}.freeze
UNENC_VAR_PATTERN = %r{(\A|[^\\])\$(::)?(\w+(-\w+)*::)*\w+(-\w+)*}.freeze
ESC_DQUOTE_PATTERN = %r{\\+"}.freeze
LBRACE_PATTERN = %r{\{}.freeze

def initialize(string)
@scanner = StringScanner.new(string)
@results = []
@interp_stack = []
@segment = []
end

raise UnterminatedStringError if results.empty? && scanner.matched?
def parse
@segment_type = :STRING

results
until scanner.eos?
if scanner.match?(START_INTERP_PATTERN)
start_interp
elsif !interp_stack.empty? && scanner.match?(LBRACE_PATTERN)
read_char
elsif scanner.match?(END_INTERP_PATTERN)
end_interp
elsif unenclosed_variable?
unenclosed_variable
elsif scanner.match?(END_STRING_PATTERN)
end_string
break if interp_stack.empty?
elsif scanner.match?(ESC_DQUOTE_PATTERN)
@segment << scanner.scan(ESC_DQUOTE_PATTERN)
else
read_char
end
end

def unenclosed_variable?
interp_stack.empty? &&
scanner.match?(UNENC_VAR_PATTERN) &&
(@segment.last.nil? ? true : !@segment.last.end_with?('\\'))
end
raise UnterminatedStringError if results.empty? && scanner.matched?

def parse_heredoc(heredoc_tag)
heredoc_name = heredoc_tag[%r{\A"?(.+?)"?(:.+?)?#{PuppetLint::Lexer::WHITESPACE_RE}*(/.*)?\Z}o, 1]
end_heredoc_pattern = %r{^\|?\s*-?\s*#{Regexp.escape(heredoc_name)}$}
interpolation = heredoc_tag.start_with?('"')

@segment_type = :HEREDOC

until scanner.eos?
if scanner.match?(end_heredoc_pattern)
end_heredoc(end_heredoc_pattern)
break if interp_stack.empty?
elsif interpolation && scanner.match?(START_INTERP_PATTERN)
start_interp
elsif interpolation && !interp_stack.empty? && scanner.match?(LBRACE_PATTERN)
read_char
elsif interpolation && unenclosed_variable?
unenclosed_variable
elsif interpolation && scanner.match?(END_INTERP_PATTERN)
end_interp
else
read_char
end
end
results
end

results
end
def unenclosed_variable?
interp_stack.empty? &&
scanner.match?(UNENC_VAR_PATTERN) &&
(@segment.last.nil? ? true : !@segment.last.end_with?('\\'))
end

def read_char
@segment << scanner.getch
def parse_heredoc(heredoc_tag)
heredoc_name = heredoc_tag[%r{\A"?(.+?)"?(:.+?)?#{PuppetLint::Lexer::WHITESPACE_RE}*(/.*)?\Z}o, 1]
end_heredoc_pattern = %r{^\|?\s*-?\s*#{Regexp.escape(heredoc_name)}$}
interpolation = heredoc_tag.start_with?('"')

return if interp_stack.empty?
@segment_type = :HEREDOC

case @segment.last
when '{'
interp_stack.push(true)
when '}'
interp_stack.pop
until scanner.eos?
if scanner.match?(end_heredoc_pattern)
end_heredoc(end_heredoc_pattern)
break if interp_stack.empty?
elsif interpolation && scanner.match?(START_INTERP_PATTERN)
start_interp
elsif interpolation && !interp_stack.empty? && scanner.match?(LBRACE_PATTERN)
read_char
elsif interpolation && unenclosed_variable?
unenclosed_variable
elsif interpolation && scanner.match?(END_INTERP_PATTERN)
end_interp
else
read_char
end
end

# Get the number of characters consumed by the StringSlurper.
#
# StringScanner from Ruby 2.0 onwards supports #charpos which returns
# the number of characters and is multibyte character aware.
#
# Prior to this, Ruby's multibyte character support in Strings was a
# bit unusual and neither String#length nor String#split behave as
# expected, so we use String#scan to split all the consumed text using
# a UTF-8 aware regex and use the length of the result
def consumed_chars
return scanner.charpos if scanner.respond_to?(:charpos)

(scanner.pre_match + scanner.matched).scan(%r{.}mu).length
end
results
end

def start_interp
if @segment.last && @segment.last == '\\'
read_char
return
end
def read_char
@segment << scanner.getch

if interp_stack.empty?
scanner.skip(START_INTERP_PATTERN)
results << [@segment_type, @segment.join]
@segment = []
else
@segment << scanner.scan(START_INTERP_PATTERN)
end
return if interp_stack.empty?

case @segment.last
when '{'
interp_stack.push(true)
when '}'
interp_stack.pop
end
end

def end_interp
if interp_stack.empty?
@segment << scanner.scan(END_INTERP_PATTERN)
return
else
interp_stack.pop
end
# Get the number of characters consumed by the StringSlurper.
#
# StringScanner from Ruby 2.0 onwards supports #charpos which returns
# the number of characters and is multibyte character aware.
#
# Prior to this, Ruby's multibyte character support in Strings was a
# bit unusual and neither String#length nor String#split behave as
# expected, so we use String#scan to split all the consumed text using
# a UTF-8 aware regex and use the length of the result
def consumed_chars
return scanner.charpos if scanner.respond_to?(:charpos)

(scanner.pre_match + scanner.matched).scan(%r{.}mu).length
end

if interp_stack.empty?
results << [:INTERP, @segment.join]
@segment = []
scanner.skip(END_INTERP_PATTERN)
else
@segment << scanner.scan(END_INTERP_PATTERN)
end
def start_interp
if @segment.last && @segment.last == '\\'
read_char
return
end

def unenclosed_variable
read_char if scanner.match?(%r{.\$})

if interp_stack.empty?
scanner.skip(START_INTERP_PATTERN)
results << [@segment_type, @segment.join]
results << [:UNENC_VAR, scanner.scan(UNENC_VAR_PATTERN)]
@segment = []
else
@segment << scanner.scan(START_INTERP_PATTERN)
end

def end_heredoc(pattern)
results << [:HEREDOC, @segment.join]
results << [:HEREDOC_TERM, scanner.scan(pattern)]
interp_stack.push(true)
end

def end_interp
if interp_stack.empty?
@segment << scanner.scan(END_INTERP_PATTERN)
return
else
interp_stack.pop
end

def end_string
if interp_stack.empty?
@segment << scanner.scan(END_STRING_PATTERN).gsub!(%r{"\Z}, '')
results << [@segment_type, @segment.join]
else
@segment << scanner.scan(END_STRING_PATTERN)
end
if interp_stack.empty?
results << [:INTERP, @segment.join]
@segment = []
scanner.skip(END_INTERP_PATTERN)
else
@segment << scanner.scan(END_INTERP_PATTERN)
end
end

def unenclosed_variable
read_char if scanner.match?(%r{.\$})

results << [@segment_type, @segment.join]
results << [:UNENC_VAR, scanner.scan(UNENC_VAR_PATTERN)]
@segment = []
end

def end_heredoc(pattern)
results << [:HEREDOC, @segment.join]
results << [:HEREDOC_TERM, scanner.scan(pattern)]
end

def end_string
if interp_stack.empty?
@segment << scanner.scan(END_STRING_PATTERN).gsub!(%r{"\Z}, '')
results << [@segment_type, @segment.join]
else
@segment << scanner.scan(END_STRING_PATTERN)
end
end
end
end

# Internal: An error thrown when an unterminated string is encountered.
class PuppetLint::Lexer::StringSlurper::UnterminatedStringError < StandardError; end
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