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Mini Shell
Mini Shell
require_relative "version"
module ErrorHighlight
# Identify the code fragment at that a given exception occurred.
#
# Options:
#
# point_type: :name | :args
# :name (default) points the method/variable name that the exception occurred.
# :args points the arguments of the method call that the exception occurred.
#
# backtrace_location: Thread::Backtrace::Location
# It locates the code fragment of the given backtrace_location.
# By default, it uses the first frame of backtrace_locations of the given exception.
#
# Returns:
# {
# first_lineno: Integer,
# first_column: Integer,
# last_lineno: Integer,
# last_column: Integer,
# snippet: String,
# script_lines: [String],
# } | nil
#
# Limitations:
#
# Currently, ErrorHighlight.spot only supports a single-line code fragment.
# Therefore, if the return value is not nil, first_lineno and last_lineno will have
# the same value. If the relevant code fragment spans multiple lines
# (e.g., Array#[] of +ary[(newline)expr(newline)]+), the method will return nil.
# This restriction may be removed in the future.
def self.spot(obj, **opts)
case obj
when Exception
exc = obj
loc = opts[:backtrace_location]
opts = { point_type: opts.fetch(:point_type, :name) }
unless loc
case exc
when TypeError, ArgumentError
opts[:point_type] = :args
end
locs = exc.backtrace_locations
return nil unless locs
loc = locs.first
return nil unless loc
opts[:name] = exc.name if NameError === obj
end
return nil unless Thread::Backtrace::Location === loc
node = RubyVM::AbstractSyntaxTree.of(loc, keep_script_lines: true)
Spotter.new(node, **opts).spot
when RubyVM::AbstractSyntaxTree::Node
Spotter.new(obj, **opts).spot
else
raise TypeError, "Exception is expected"
end
rescue SyntaxError,
SystemCallError, # file not found or something
ArgumentError # eval'ed code
return nil
end
class Spotter
class NonAscii < Exception; end
private_constant :NonAscii
def initialize(node, point_type: :name, name: nil)
@node = node
@point_type = point_type
@name = name
# Not-implemented-yet options
@arg = nil # Specify the index or keyword at which argument caused the TypeError/ArgumentError
@multiline = false # Allow multiline spot
@fetch = -> (lineno, last_lineno = lineno) do
snippet = @node.script_lines[lineno - 1 .. last_lineno - 1].join("")
snippet += "\n" unless snippet.end_with?("\n")
# It require some work to support Unicode (or multibyte) characters.
# Tentatively, we stop highlighting if the code snippet has non-ascii characters.
# See https://github.com/ruby/error_highlight/issues/4
raise NonAscii unless snippet.ascii_only?
snippet
end
end
def spot
return nil unless @node
case @node.type
when :CALL, :QCALL
case @point_type
when :name
spot_call_for_name
when :args
spot_call_for_args
end
when :ATTRASGN
case @point_type
when :name
spot_attrasgn_for_name
when :args
spot_attrasgn_for_args
end
when :OPCALL
case @point_type
when :name
spot_opcall_for_name
when :args
spot_opcall_for_args
end
when :FCALL
case @point_type
when :name
spot_fcall_for_name
when :args
spot_fcall_for_args
end
when :VCALL
spot_vcall
when :OP_ASGN1
case @point_type
when :name
spot_op_asgn1_for_name
when :args
spot_op_asgn1_for_args
end
when :OP_ASGN2
case @point_type
when :name
spot_op_asgn2_for_name
when :args
spot_op_asgn2_for_args
end
when :CONST
spot_vcall
when :COLON2
spot_colon2
when :COLON3
spot_vcall
when :OP_CDECL
spot_op_cdecl
end
if @snippet && @beg_column && @end_column && @beg_column < @end_column
return {
first_lineno: @beg_lineno,
first_column: @beg_column,
last_lineno: @end_lineno,
last_column: @end_column,
snippet: @snippet,
script_lines: @node.script_lines,
}
else
return nil
end
rescue NonAscii
nil
end
private
# Example:
# x.foo
# ^^^^
# x.foo(42)
# ^^^^
# x&.foo
# ^^^^^
# x[42]
# ^^^^
# x += 1
# ^
def spot_call_for_name
nd_recv, mid, nd_args = @node.children
lineno = nd_recv.last_lineno
lines = @fetch[lineno, @node.last_lineno]
if mid == :[] && lines.match(/\G[\s)]*(\[(?:\s*\])?)/, nd_recv.last_column)
@beg_column = $~.begin(1)
@snippet = lines[/.*\n/]
@beg_lineno = @end_lineno = lineno
if nd_args
if nd_recv.last_lineno == nd_args.last_lineno && @snippet.match(/\s*\]/, nd_args.last_column)
@end_column = $~.end(0)
end
else
if lines.match(/\G[\s)]*?\[\s*\]/, nd_recv.last_column)
@end_column = $~.end(0)
end
end
elsif lines.match(/\G[\s)]*?(\&?\.)(\s*?)(#{ Regexp.quote(mid) }).*\n/, nd_recv.last_column)
lines = $` + $&
@beg_column = $~.begin($2.include?("\n") ? 3 : 1)
@end_column = $~.end(3)
if i = lines[..@beg_column].rindex("\n")
@beg_lineno = @end_lineno = lineno + lines[..@beg_column].count("\n")
@snippet = lines[i + 1..]
@beg_column -= i + 1
@end_column -= i + 1
else
@snippet = lines
@beg_lineno = @end_lineno = lineno
end
elsif mid.to_s =~ /\A\W+\z/ && lines.match(/\G\s*(#{ Regexp.quote(mid) })=.*\n/, nd_recv.last_column)
@snippet = $` + $&
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
end
# Example:
# x.foo(42)
# ^^
# x[42]
# ^^
# x += 1
# ^
def spot_call_for_args
_nd_recv, _mid, nd_args = @node.children
if nd_args && nd_args.first_lineno == nd_args.last_lineno
fetch_line(nd_args.first_lineno)
@beg_column = nd_args.first_column
@end_column = nd_args.last_column
end
# TODO: support @arg
end
# Example:
# x.foo = 1
# ^^^^^^
# x[42] = 1
# ^^^^^^
def spot_attrasgn_for_name
nd_recv, mid, nd_args = @node.children
*nd_args, _nd_last_arg, _nil = nd_args.children
fetch_line(nd_recv.last_lineno)
if mid == :[]= && @snippet.match(/\G[\s)]*(\[)/, nd_recv.last_column)
@beg_column = $~.begin(1)
args_last_column = $~.end(0)
if nd_args.last && nd_recv.last_lineno == nd_args.last.last_lineno
args_last_column = nd_args.last.last_column
end
if @snippet.match(/[\s)]*\]\s*=/, args_last_column)
@end_column = $~.end(0)
end
elsif @snippet.match(/\G[\s)]*(\.\s*#{ Regexp.quote(mid.to_s.sub(/=\z/, "")) }\s*=)/, nd_recv.last_column)
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
end
# Example:
# x.foo = 1
# ^
# x[42] = 1
# ^^^^^^^
# x[] = 1
# ^^^^^
def spot_attrasgn_for_args
nd_recv, mid, nd_args = @node.children
fetch_line(nd_recv.last_lineno)
if mid == :[]= && @snippet.match(/\G[\s)]*\[/, nd_recv.last_column)
@beg_column = $~.end(0)
if nd_recv.last_lineno == nd_args.last_lineno
@end_column = nd_args.last_column
end
elsif nd_args && nd_args.first_lineno == nd_args.last_lineno
@beg_column = nd_args.first_column
@end_column = nd_args.last_column
end
# TODO: support @arg
end
# Example:
# x + 1
# ^
# +x
# ^
def spot_opcall_for_name
nd_recv, op, nd_arg = @node.children
fetch_line(nd_recv.last_lineno)
if nd_arg
# binary operator
if @snippet.match(/\G[\s)]*(#{ Regexp.quote(op) })/, nd_recv.last_column)
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
else
# unary operator
if @snippet[...nd_recv.first_column].match(/(#{ Regexp.quote(op.to_s.sub(/@\z/, "")) })\s*\(?\s*\z/)
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
end
end
# Example:
# x + 1
# ^
def spot_opcall_for_args
_nd_recv, _op, nd_arg = @node.children
if nd_arg && nd_arg.first_lineno == nd_arg.last_lineno
# binary operator
fetch_line(nd_arg.first_lineno)
@beg_column = nd_arg.first_column
@end_column = nd_arg.last_column
end
end
# Example:
# foo(42)
# ^^^
# foo 42
# ^^^
def spot_fcall_for_name
mid, _nd_args = @node.children
fetch_line(@node.first_lineno)
if @snippet.match(/(#{ Regexp.quote(mid) })/, @node.first_column)
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
end
# Example:
# foo(42)
# ^^
# foo 42
# ^^
def spot_fcall_for_args
_mid, nd_args = @node.children
if nd_args && nd_args.first_lineno == nd_args.last_lineno
# binary operator
fetch_line(nd_args.first_lineno)
@beg_column = nd_args.first_column
@end_column = nd_args.last_column
end
end
# Example:
# foo
# ^^^
def spot_vcall
if @node.first_lineno == @node.last_lineno
fetch_line(@node.last_lineno)
@beg_column = @node.first_column
@end_column = @node.last_column
end
end
# Example:
# x[1] += 42
# ^^^ (for [])
# x[1] += 42
# ^ (for +)
# x[1] += 42
# ^^^^^^ (for []=)
def spot_op_asgn1_for_name
nd_recv, op, nd_args, _nd_rhs = @node.children
fetch_line(nd_recv.last_lineno)
if @snippet.match(/\G[\s)]*(\[)/, nd_recv.last_column)
bracket_beg_column = $~.begin(1)
args_last_column = $~.end(0)
if nd_args && nd_recv.last_lineno == nd_args.last_lineno
args_last_column = nd_args.last_column
end
if @snippet.match(/\s*\](\s*)(#{ Regexp.quote(op) })=()/, args_last_column)
case @name
when :[], :[]=
@beg_column = bracket_beg_column
@end_column = $~.begin(@name == :[] ? 1 : 3)
when op
@beg_column = $~.begin(2)
@end_column = $~.end(2)
end
end
end
end
# Example:
# x[1] += 42
# ^^^^^^^^
def spot_op_asgn1_for_args
nd_recv, mid, nd_args, nd_rhs = @node.children
fetch_line(nd_recv.last_lineno)
if mid == :[]= && @snippet.match(/\G\s*\[/, nd_recv.last_column)
@beg_column = $~.end(0)
if nd_recv.last_lineno == nd_rhs.last_lineno
@end_column = nd_rhs.last_column
end
elsif nd_args && nd_args.first_lineno == nd_rhs.last_lineno
@beg_column = nd_args.first_column
@end_column = nd_rhs.last_column
end
# TODO: support @arg
end
# Example:
# x.foo += 42
# ^^^ (for foo)
# x.foo += 42
# ^ (for +)
# x.foo += 42
# ^^^^^^^ (for foo=)
def spot_op_asgn2_for_name
nd_recv, _qcall, attr, op, _nd_rhs = @node.children
fetch_line(nd_recv.last_lineno)
if @snippet.match(/\G[\s)]*(\.)\s*#{ Regexp.quote(attr) }()\s*(#{ Regexp.quote(op) })(=)/, nd_recv.last_column)
case @name
when attr
@beg_column = $~.begin(1)
@end_column = $~.begin(2)
when op
@beg_column = $~.begin(3)
@end_column = $~.end(3)
when :"#{ attr }="
@beg_column = $~.begin(1)
@end_column = $~.end(4)
end
end
end
# Example:
# x.foo += 42
# ^^
def spot_op_asgn2_for_args
_nd_recv, _qcall, _attr, _op, nd_rhs = @node.children
if nd_rhs.first_lineno == nd_rhs.last_lineno
fetch_line(nd_rhs.first_lineno)
@beg_column = nd_rhs.first_column
@end_column = nd_rhs.last_column
end
end
# Example:
# Foo::Bar
# ^^^^^
def spot_colon2
nd_parent, const = @node.children
if nd_parent.last_lineno == @node.last_lineno
fetch_line(nd_parent.last_lineno)
@beg_column = nd_parent.last_column
@end_column = @node.last_column
else
@snippet = @fetch[@node.last_lineno]
if @snippet[...@node.last_column].match(/#{ Regexp.quote(const) }\z/)
@beg_column = $~.begin(0)
@end_column = $~.end(0)
end
end
end
# Example:
# Foo::Bar += 1
# ^^^^^^^^
def spot_op_cdecl
nd_lhs, op, _nd_rhs = @node.children
*nd_parent_lhs, _const = nd_lhs.children
if @name == op
@snippet = @fetch[nd_lhs.last_lineno]
if @snippet.match(/\G\s*(#{ Regexp.quote(op) })=/, nd_lhs.last_column)
@beg_column = $~.begin(1)
@end_column = $~.end(1)
end
else
# constant access error
@end_column = nd_lhs.last_column
if nd_parent_lhs.empty? # example: ::C += 1
if nd_lhs.first_lineno == nd_lhs.last_lineno
@snippet = @fetch[nd_lhs.last_lineno]
@beg_column = nd_lhs.first_column
end
else # example: Foo::Bar::C += 1
if nd_parent_lhs.last.last_lineno == nd_lhs.last_lineno
@snippet = @fetch[nd_lhs.last_lineno]
@beg_column = nd_parent_lhs.last.last_column
end
end
end
end
def fetch_line(lineno)
@beg_lineno = @end_lineno = lineno
@snippet = @fetch[lineno]
end
end
private_constant :Spotter
end
Zerion Mini Shell 1.0