class Byebug::TracevarCommand - byebug-9.0.6 Documentation

# class Byebug::TracevarCommand

Show (and possibily stop) at every line that changes a global variable.

### Public Class Methods

description() click to toggle source

    # File lib/byebug/commands/tracevar.rb, line 14
    def self.description
      <<-EOD
        tr[acevar] <variable> [[no]stop]

        #{short_description}

        If "stop" is specified, execution will stop every time the variable
        changes its value. If nothing or "nostop" is specified, execution won't
        stop, changes will just be logged in byebug's output.
      EOD
    end

regexp() click to toggle source

    # File lib/byebug/commands/tracevar.rb, line 8
    def self.regexp
      /^\s* tr(?:acevar)? (?: \s+ (\S+))?  # (variable-name)?
                          (?: \s+ (stop|nostop))?
       \s*$/x
    end

short_description() click to toggle source

    # File lib/byebug/commands/tracevar.rb, line 26
    def self.short_description
      'Enables tracing of a global variable'
    end

### Public Instance Methods

execute() click to toggle source

    # File lib/byebug/commands/tracevar.rb, line 30
    def execute
      var = @match[1]
      return errmsg(pr('trace.errors.needs_global_variable')) unless var

      unless global_variables.include?(:"#{var}")
        return errmsg(pr('trace.errors.var_is_not_global', name: var))
      end

      stop = @match[2] && @match[2] !~ /nostop/

      instance_eval do
        trace_var(:"#{var}") { |val| on_change(var, val, stop) }
      end

      puts pr('trace.messages.success', var: var)
    end

### Private Instance Methods

on_change(name, value, stop) click to toggle source

    # File lib/byebug/commands/tracevar.rb, line 49
    def on_change(name, value, stop)
      puts pr('trace.messages.on_change', name: name, value: value)

      context.step_out(1, false) if stop
    end