alias_processor.rb in brakeman-5.1.0

- old
+ new

@@ -206,10 +206,19 @@
       return Sexp.new(:hash).line(exp.line)
     elsif exp == RAILS_TEST or exp == RAILS_DEV
       return Sexp.new(:false).line(exp.line)
     end
 
+    # For the simplest case of `Foo.thing`
+    if node_type? target, :const and first_arg.nil?
+      if tracker and (klass = tracker.find_class(class_name(target.value)))
+        if return_value = klass.get_simple_method_return_value(:class, method)
+          return return_value.deep_clone(exp.line)
+        end
+      end
+    end
+
     #See if it is possible to simplify some basic cases
     #of addition/concatenation.
     case method
     when :+
       if array? target and array? first_arg
@@ -218,17 +227,32 @@
         exp = join_strings(target, first_arg, exp)
       elsif number? first_arg
         exp = math_op(:+, target, first_arg, exp)
       end
     when :-, :*, :/
-      exp = math_op(method, target, first_arg, exp)
+      if method == :* and array? target
+        if string? first_arg
+          exp = process_array_join(target, first_arg)
+        end
+      else
+        exp = math_op(method, target, first_arg, exp)
+      end
     when :[]
       if array? target
         exp = process_array_access(target, exp.args, exp)
       elsif hash? target
         exp = process_hash_access(target, first_arg, exp)
       end
+    when :fetch
+      if array? target
+        # Not dealing with default value
+        # so just pass in first argument, but process_array_access expects
+        # an array of arguments.
+        exp = process_array_access(target, [first_arg], exp)
+      elsif hash? target
+        exp = process_hash_access(target, first_arg, exp)
+      end
     when :merge!, :update
       if hash? target and hash? first_arg
          target = process_hash_merge! target, first_arg
          env[target_var] = target
          return target
@@ -264,10 +288,16 @@
         return target
       else
         target = find_push_target(target_var)
         env[target] = exp unless target.nil? # Happens in TemplateAliasProcessor
       end
+    when :push
+      if array? target
+        target << first_arg
+        env[target_var] = target
+        return target
+      end
     when :first
       if array? target and first_arg.nil? and sexp? target[1]
         exp = target[1]
       end
     when :freeze
@@ -277,35 +307,51 @@
     when :dup
       unless target.nil?
         exp = target
       end
     when :join
-      if array? target and target.length > 2 and (string? first_arg or first_arg.nil?)
+      if array? target and (string? first_arg or first_arg.nil?)
         exp = process_array_join(target, first_arg)
       end
     when :!
       #  Convert `!!a` to boolean
       if call? target and target.method == :!
         exp = s(:or, s(:true).line(exp.line), s(:false).line(exp.line)).line(exp.line)
       end
+    when :values
+      # Hash literal
+      if node_type? target, :hash
+        exp = hash_values(target)
+      end
+    when :values_at
+      if node_type? target, :hash
+        exp = hash_values_at target, exp.args
+      end
     end
 
     exp
   end
 
   # Painful conversion of Array#join into string interpolation
   def process_array_join array, join_str
+    # Empty array
+    if array.length == 1
+      return s(:str, '').line(array.line)
+    end
+
     result = s().line(array.line)
 
     join_value = if string? join_str
                    join_str.value
                  else
                    nil
                  end
 
-    array[1..-2].each do |e|
-      result << join_item(e, join_value)
+    if array.length > 2
+      array[1..-2].each do |e|
+        result << join_item(e, join_value)
+      end
     end
 
     result << join_item(array.last, nil)
 
     # Combine the strings at the beginning because that's what RubyParser does
@@ -330,19 +376,27 @@
     end
 
     result.unshift combined_first
 
     # Have to fix up strings that follow interpolation
-    result.reduce(s(:dstr).line(array.line)) do |memo, e|
+    string = result.reduce(s(:dstr).line(array.line)) do |memo, e|
       if string? e and node_type? memo.last, :evstr
         e.value = "#{join_value}#{e.value}"
       elsif join_value and node_type? memo.last, :evstr and node_type? e, :evstr
         memo << s(:str, join_value).line(e.line)
       end
 
       memo << e
     end
+
+    # Convert (:dstr, "hello world")
+    # to (:str, "hello world")
+    if string.length == 2 and string.last.is_a? String
+      string[0] = :str
+    end
+
+    string
   end
 
   def join_item item, join_value
     if item.is_a? String
       "#{item}#{join_value}"
@@ -747,10 +801,22 @@
     env[match] = get_rhs(exp)
 
     exp
   end
 
+  def hash_or_array_include_all_literals? exp
+    return unless call? exp and sexp? exp.target
+    target = exp.target
+
+    case target.node_type
+    when :hash
+      hash_include_all_literals? exp
+    else
+      array_include_all_literals? exp
+    end
+  end
+
   # Check if exp is a call to Array#include? on an array literal
   # that contains all literal values. For example:
   #
   #    [1, 2, "a"].include? x
   #
@@ -765,10 +831,20 @@
     [:detect, :find].include? exp.method and
     exp.first_arg.nil? and
     (all_literals? exp.target or dir_glob? exp.target)
   end
 
+  # Check if exp is a call to Hash#include? on a hash literal
+  # that contains all literal values. For example:
+  #
+  #    {x: 1}.include? x
+  def hash_include_all_literals? exp
+    call? exp and
+    exp.method == :include? and
+    all_literals? exp.target, :hash
+  end
+
   #Sets @inside_if = true
   def process_if exp
     if @ignore_ifs.nil?
       @ignore_ifs = @tracker && @tracker.options[:ignore_ifs]
     end
@@ -805,19 +881,19 @@
       branch_scopes = []
       exps.each_with_index do |branch, i|
         scope do
           @branch_env = env.current
           branch_index = 2 + i # s(:if, condition, then_branch, else_branch)
-          if i == 0 and array_include_all_literals? condition
+          if i == 0 and hash_or_array_include_all_literals? condition
             # If the condition is ["a", "b"].include? x
             # set x to "a" inside the true branch
             var = condition.first_arg
             previous_value = env.current[var]
             env.current[var] = safe_literal(var.line)
             exp[branch_index] = process_if_branch branch
             env.current[var] = previous_value
-          elsif i == 1 and array_include_all_literals? condition and early_return? branch
+          elsif i == 1 and hash_or_array_include_all_literals? condition and early_return? branch
             var = condition.first_arg
             env.current[var] = safe_literal(var.line)
             exp[branch_index] = process_if_branch branch
           else
             exp[branch_index] = process_if_branch branch
@@ -1011,11 +1087,11 @@
 
   def get_call_value call
     method_name = call.method
 
     #Look for helper methods and see if we can get a return value
-    if found_method = find_method(method_name, @current_class)
-      helper = found_method[:method]
+    if found_method = tracker.find_method(method_name, @current_class)
+      helper = found_method.src
 
       if sexp? helper
         value = process_helper_method helper, call.args
         value.line(call.line)
         return value