Fix Ruby 2.6 __LINE__ and __FILE__ deprecated usage in Binding#eval

Author: gsamokovarov

lib/web_console.rb

@@ -17,6 +17,7 @@ module WebConsole
   autoload :Template
   autoload :Middleware
   autoload :Context
+  autoload :SourceLocation
 
   autoload_at "web_console/errors" do
     autoload :Error

lib/web_console/exception_mapper.rb

@@ -22,13 +22,15 @@ def guess_binding_for_index(index)
         line = line.to_i
 
         @bindings.find do |binding|
-          binding.eval("__FILE__") == file && binding.eval("__LINE__") == line
+          source_location = SourceLocation.new(binding)
+          source_location.path == file && source_location.lineno == line
         end
       end
 
       def guess_the_first_application_binding
         @bindings.find do |binding|
-          binding.eval("__FILE__").to_s.start_with?(Rails.root.to_s)
+          source_location = SourceLocation.new(binding)
+          source_location.path.to_s.start_with?(Rails.root.to_s)
         end
       end
   end

lib/web_console/source_location.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class SourceLocation
+  def initialize(binding)
+    @binding = binding
+  end
+
+  if RUBY_VERSION >= "2.6"
+    def path() @binding.source_location.first end
+    def lineno() @binding.source_location.last end
+  else
+    def path() @binding.eval("__FILE__") end
+    def lineno() @binding.eval("__LINE__") end
+  end
+end

test/web_console/exception_mapper_test.rb

@@ -9,7 +9,7 @@ class ExcetionMapperTest < ActiveSupport::TestCase
 
       mapper = ExceptionMapper.new(External.exception)
 
-      assert_equal __FILE__, mapper.first.eval("__FILE__")
+      assert_equal __FILE__, SourceLocation.new(mapper.first).path
     end
 
     test ".[] tries match the binding for trace index" do
@@ -19,8 +19,8 @@ class ExcetionMapperTest < ActiveSupport::TestCase
       last_index = exception.backtrace.count - 1
       file, line = exception.backtrace.last.split(":")
 
-      assert_equal file, mapper[last_index].eval("__FILE__")
-      assert_equal line.to_i, mapper[last_index].eval("__LINE__")
+      assert_equal file, SourceLocation.new(mapper[last_index]).path
+      assert_equal line.to_i, SourceLocation.new(mapper[last_index]).lineno
     end
 
     test ".[] fall backs to index if no trace can be found" do

test/web_console/integration_test.rb

@@ -7,37 +7,37 @@ class IntegrationTest < ActiveSupport::TestCase
     test "Exception#bindings returns all the bindings of where the error originated" do
       exc = FlatScenario.new.call
 
-      assert_equal 6, exc.bindings.first.eval("__LINE__")
+      assert_equal 6, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "Exception#bindings returns all the bindings for a custom error" do
       exc = CustomErrorScenario.new.call
 
-      assert_equal 8, exc.bindings.first.eval("__LINE__")
+      assert_equal 8, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "Exception#bindings returns all the bindings for a bad custom error" do
       exc = BadCustomErrorScenario.new.call
 
-      assert_equal 13, exc.bindings.first.eval("__LINE__")
+      assert_equal 13, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "Exception#bindings goes down the stack" do
       exc = BasicNestedScenario.new.call
 
-      assert_equal 14, exc.bindings.first.eval("__LINE__")
+      assert_equal 14, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "Exception#bindings inside of an eval" do
       exc = EvalNestedScenario.new.call
 
-      assert_equal 14, exc.bindings.first.eval("__LINE__")
+      assert_equal 14, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "re-raising doesn't lose Exception#bindings information" do
       exc = ReraisedScenario.new.call
 
-      assert_equal 6, exc.bindings.first.eval("__LINE__")
+      assert_equal 6, SourceLocation.new(exc.bindings.first).lineno
     end
 
     test "Exception#bindings is empty when exception is still not raised" do

test/web_console/middleware_test.rb

@@ -162,7 +162,7 @@ def headers
       Session.stubs(:from).returns(session)
 
       get "/", params: nil
-      put "/repl_sessions/#{session.id}", xhr: true, params: { input: "__LINE__" }
+      put "/repl_sessions/#{session.id}", xhr: true, params: { input: "line" }
 
       assert_equal("=> #{line}\n", JSON.parse(response.body)["output"])
     end
@@ -181,10 +181,10 @@ def headers
     test "can be changed mount point" do
       Middleware.mount_point = "/customized/path"
 
-      session, line = Session.new([binding]), __LINE__
-      put "/customized/path/repl_sessions/#{session.id}", params: { input: "__LINE__" }, xhr: true
+      session, value = Session.new([binding]), __LINE__
+      put "/customized/path/repl_sessions/#{session.id}", params: { input: "value" }, xhr: true
 
-      assert_equal("=> #{line}\n", JSON.parse(response.body)["output"])
+      assert_equal("=> #{value}\n", JSON.parse(response.body)["output"])
     end
 
     test "can return context information by passing a context param" do

test/web_console/session_test.rb

@@ -4,17 +4,17 @@
 
 module WebConsole
   class SessionTest < ActiveSupport::TestCase
-    class LineAwareError < StandardError
-      def self.raise
-        ::Kernel.raise new(__LINE__)
+    class ValueAwareError < StandardError
+      def self.raise(value)
+        ::Kernel.raise self, value
       rescue => exc
         exc
       end
 
-      attr_reader :line
+      attr_reader :value
 
-      def initialize(line)
-        @line = line
+      def initialize(value)
+        @value = value
       end
     end
 
@@ -52,38 +52,39 @@ def eval(string)
     end
 
     test "#from can create session from a single binding" do
-      saved_line, saved_binding = __LINE__, binding
+      value, saved_binding = __LINE__, binding
       Thread.current[:__web_console_binding] = saved_binding
 
       session = Session.from(__web_console_binding: saved_binding)
 
-      assert_equal "=> #{saved_line}\n", session.eval("__LINE__")
+      assert_equal "=> #{value}\n", session.eval("value")
     end
 
     test "#from can create session from an exception" do
-      exc = LineAwareError.raise
+      value = __LINE__
+      exc = ValueAwareError.raise(value)
 
       session = Session.from(__web_console_exception: exc)
 
-      assert_equal "=> #{exc.line}\n", session.eval("__LINE__")
+      assert_equal "=> #{exc.value}\n", session.eval("value")
     end
 
     test "#from can switch to bindings" do
-      exc, saved_line = LineAwareError.raise, __LINE__
+      value = __LINE__
+      exc = ValueAwareError.raise(value)
 
       session = Session.from(__web_console_exception: exc)
       session.switch_binding_to(1)
 
-      assert_equal "=> #{saved_line}\n", session.eval("__LINE__")
+      assert_equal "=> #{value}\n", session.eval("value")
     end
 
     test "#from prioritizes exceptions over bindings" do
-      exc, saved_line = LineAwareError.raise, __LINE__
+      exc = ValueAwareError.raise(42)
 
       session = Session.from(__web_console_exception: exc, __web_console_binding: binding)
-      session.switch_binding_to(1)
 
-      assert_equal "=> #{saved_line}\n", session.eval("__LINE__")
+      assert_equal "=> WebConsole::SessionTest::ValueAwareError\n", session.eval("self")
     end
   end
 end