John's Free Energy: Exploring Ruby on Rails Projects With Metaprogramming: Running the App

Running the app

Time to try out ruby-explorer on our Rails app:

jmax@deepthought ~/projects/ruby-explorer $ bin/ruby-explorer ../bare-rails
jmax@deepthought ~/projects/ruby-explorer $ load(["/home/jmax/projects/bare-rails/bin/spring"])
require(["rubygems"])
require(["rubygems"]): returned false
require(["bundler"])
require(["bundler/compatibility_guard"])
require(["rubygems"])
require(["rubygems"]): returned false
require(["bundler/version"])
require(["rubygems"])
require(["rubygems"]): returned false
  :
  :
require(["spring/configuration"])
require(["spring/configuration"]): returned false
load(["/home/jmax/projects/bare-rails/bin/rails"])
load(["/home/jmax/projects/bare-rails/bin/spring"])
load(["/home/jmax/projects/bare-rails/bin/spring"]): returned true
require_relative(["../config/boot"])
Traceback (most recent call last):
    28: from bin/rails:3:in `<main>'
    27: from /home/jmax/projects/ruby-explorer/src/probe.rb:28:in `block in wrap'
    26: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `block in install'
    25: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `call'
    24: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `load'
    23: from /home/jmax/projects/bare-rails/bin/spring:15:in `<top (required)>'
    22: from /home/jmax/projects/ruby-explorer/src/probe.rb:28:in `block in wrap'
    21: from /home/jmax/projects/ruby-explorer/src/probe.rb:5:in `block in install'
    20: from /home/jmax/projects/ruby-explorer/src/probe.rb:5:in `call'
    19: from /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    18: from /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    17: from /home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `<top (required)>'
    16: from /home/jmax/projects/ruby-explorer/src/probe.rb:28:in `block in wrap'
    15: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `block in install'
    14: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `call'
    13: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `load'
    12: from /home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/bin/spring:49:in `<top (required)>'
    11: from /home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client.rb:30:in `run'
    10: from /home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client/command.rb:7:in `call'
     9: from /home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `call'
     8: from /home/jmax/projects/ruby-explorer/src/probe.rb:28:in `block in wrap'
     7: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `block in install'
     6: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `call'
     5: from /home/jmax/projects/ruby-explorer/src/probe.rb:19:in `load'
     4: from /home/jmax/projects/bare-rails/bin/rails:8:in `<top (required)>'
     3: from /home/jmax/projects/ruby-explorer/src/probe.rb:28:in `block in wrap'
     2: from /home/jmax/projects/ruby-explorer/src/probe.rb:12:in `block in install'
     1: from /home/jmax/projects/ruby-explorer/src/probe.rb:12:in `call'
/home/jmax/projects/ruby-explorer/src/probe.rb:12:in `require_relative': cannot load such file -- /home/jmax/projects/ruby-explorer/config/boot (LoadError)

Works great. Right up until the first call to require_relative, when it blows up. Our problem is that require_relative looks for the specified file relative to the file that it's called from. And our wrapper calls the original require_relative from a different file than our wrapper was called from. Bah. How annoying.

Faking require_relative

How to deal with this? Well, if we can figure out what file our wrapper is getting called from, then we can find the file ourselves and call require. Amazingly, Ruby actually lets us do that. The caller method gives us a copy of the call stack. Sticking a debug print into our require_relative wrapper, so we can see exactly what we have, like this:

    wrap(Kernel, :require_relative) do |original_require_relative, args|
      # DEBUG
      puts caller

      puts "require_relative(#{args})"
      return_value= original_require_relative.call(*args)
      puts "require_relative(#{args}): returned #{return_value}"
      return_value
    end

We get the result:

/home/jmax/projects/ruby-explorer/src/probe.rb:31:in `block in wrap'
/home/jmax/projects/bare-rails/bin/rails:8:in `<top (required)>'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `load'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `call'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `block in install'
/home/jmax/projects/ruby-explorer/src/probe.rb:31:in `block in wrap'
/home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `call'
/home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client/command.rb:7:in `call'
/home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/client.rb:30:in `run'
/home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/bin/spring:49:in `<top (required)>'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `load'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `call'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `block in install'
/home/jmax/projects/ruby-explorer/src/probe.rb:31:in `block in wrap'
/home/jmax/.rvm/gems/ruby-2.5.5/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `<top (required)>'
/home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in `require'
/home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:54:in `require'
/home/jmax/projects/ruby-explorer/src/probe.rb:5:in `call'
/home/jmax/projects/ruby-explorer/src/probe.rb:5:in `block in install'
/home/jmax/projects/ruby-explorer/src/probe.rb:31:in `block in wrap'
/home/jmax/projects/bare-rails/bin/spring:15:in `<top (required)>'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `load'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `call'
/home/jmax/projects/ruby-explorer/src/probe.rb:22:in `block in install'
/home/jmax/projects/ruby-explorer/src/probe.rb:31:in `block in wrap'
bin/rails:3:in `<main>'

The first entry is us; when we call caller, we push a frame onto the stack, and caller dutifully reports that to us. The second entry is in the middle of wrap. The third one is the code that called our wrapper, and the one we're interested in. We can pass a couple arguments to caller in case we're only interested in part of the stack, as here. By changing our call to caller(2,1), we can get just the frame we're interested in.

The return value from caller is still an array, even though we only asked for one entry. Using first, we can get the first (and only) element of the array. We could do the same thing with a subscript, but I think using first is slightly clearer. We can then use split and another call to first to get the actual path of our caller. Putting it all together, we use caller.first.split(":").first - and we have the full path of the file that called our wrapper.

File path in hand, our wrapper for require_relative becomes:

    wrap(Kernel, :require_relative) do |original_require_relative, args|
      puts "require_relative(#{args})"

      caller_path= caller(2,1).first.split(":").first
      base_directory= Pathname.new(caller_path).dirname
      absolute_file= "#{base_directory}/#{args.first}"

      return_value= require(absolute_file)

      puts "require(#{absolute_file}): returned #{return_value}"
      return_value
    end

And when we try running ruby-explorer again, we get:

jmax@deepthought ~/projects/ruby-explorer $ bin/ruby-explorer ../bare-rails
jmax@deepthought ~/projects/ruby-explorer $ load(["/home/jmax/projects/bare-rails/bin/spring"])
require(["rubygems"])
require(["rubygems"]): returned false
require(["bundler"])
require(["bundler/compatibility_guard"])
require(["rubygems"])
require(["rubygems"]): returned false
require(["bundler/version"])
require(["rubygems"])
require(["rubygems"]): returned false
  :
  :
require_relative(["../config/boot"])
require(["/home/jmax/projects/bare-rails/bin/../config/boot"])
  :
  :
=> Booting Puma
=> Rails 6.0.2.2 application starting in development
=> Run `rails server --help` for more startup options
  :
  :
load(["/home/jmax/.rvm/gems/ruby-2.5.5/gems/actionmailbox-6.0.2.2/config/routes.rb", false])
load(["/home/jmax/.rvm/gems/ruby-2.5.5/gems/actionmailbox-6.0.2.2/config/routes.rb", false]): returned true
load(["/home/jmax/.rvm/gems/ruby-2.5.5/gems/activestorage-6.0.2.2/config/routes.rb", false])
load(["/home/jmax/.rvm/gems/ruby-2.5.5/gems/activestorage-6.0.2.2/config/routes.rb", false]): returned true
Puma starting in single mode...
* Version 4.3.3 (ruby 2.5.5-p157), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://127.0.0.1:3000
* Listening on tcp://[::1]:3000
Use Ctrl-C to stop

Our target app started! Success! Or is it?

Another thing to cope with

Thinking back to our original problem, we remember that it was "I want to know all of the files loaded by a Rails project." Have we done that? Sadly, no. Look at the very first call to require in our output. We report that we've been asked to require("rubygems"). Where is that file located?

To answer that, we need to dig into the details of the functions we're wrapping. The easiest case is require_relative. It simply looks for the specified file relative to the current file.

Life is more complicated for require and load. In those cases, the code looks at the first character of the filename. If it's '/', '~', or '.', then it just looks for the file as specified, as an absolute path, a path relative to the current user's home directory, or relative to the current directory, respectively. Pretty simple.

But most of the calls to require in our output so far aren't like that. They look like, for example, require('bundler'). In these cases, Ruby will use the global variable $LOAD_PATH, which consists of a list of directories. Ruby checks each of them, in order, looking to see if (in our example) there's a file called bundler, bundler.rb, or bundler.so. If so, it loads that file. If not, it checks the next directory.

Just to make life even more interesting, in the case of require, RubyGems gets into the act as well. It actually does something like what we're doing; it replaces Ruby's require with it's own version. Its version searches over the $LOAD_PATH, as described above. If it doesn't find the file that way, then it searches the installed gems for the file. If it finds the file, it activates the gem that it found the file in.

What 'activates' means in this context is that the gem's directories are added to $LOAD_PATH. This is a little vague, because it's actually the gem's code which adds entries to $LOAD_PATH. Usually, just the gem's lib directory will be added, but that's only a convention, so we can't rely on it.

This so-called 'RubyGems hack' is actually the mechanism that resolves most of our calls, so we can't neglect it.

So, how do we deal with all this? Checking $LOAD_PATH isn't too bad; we can implement that. Duplicating the RubyGems hack, on the other hand, would require repeating a significant chunk of RubyGems' code. Worse, some of the selected gem's code would likely get executed twice; once by RubyGems, and once by us.

We're saved by a few things:

First, when we require a file, require returns false if the file was already loaded. Remember that require promises to never load the same file twice. So if our call-through to the original version of require returns false, we're done; no additional file was loaded by the call.
Second, require_relative makes the same promise; if it returns false, we're done.
Third, the way in which require and require_relative implement that feature is helpful to us. They do it by stashing the absolute path of each file pulled in by require or require_relative in the array $LOADED_FEATURES. So if require or require_relative returns true, we can search $LOADED_FEATURES to pick up the absolute path of the loaded file.

In summary, for require and require_relative, we can check $LOADED_FEATURES after the call. For load, we can see if the file exists relative to the current directory, and if not, check $LOAD_PATH.

Finding `require`'d files

So, let's implement tests for all this. Taking require and require_relative first, it seems good to implement the code for finding the actual file loaded in a new method, require_file(file, loaded_features). The first argument is the filename passed to require or require_relative, and the second is $LOADED_FEATURES. This brings out an interesting feature of TDD; we have that second argument to make testing easier, but it's actually a better design; the method isn't coupled to a global variable any more.

Our tests for it are:

  describe "#require_file" do
    it "doesn't find a file that hasn't been loaded" do
      expect(the_probe.require_file("a-file", [])).to be_nil
    end

    it "finds a loaded file with no path and no extension when the loaded file has a .rb extension" do
      expect(the_probe.require_file("a-file", ["/some/path/wrong-file.rb", "/some/path/a-file.rb"])).
        to eq("/some/path/a-file.rb")
    end

    it "finds a loaded file with no path and no extension when the loaded file has a .so extension" do
      expect(the_probe.require_file("a-file", ["/some/path/wrong-file.rb", "/some/path/a-file.so"])).
        to eq("/some/path/a-file.so")
    end

    it "finds a loaded file with no path and an .rb extension when the loaded file has a .rb extension" do
      expect(the_probe.require_file("a-file.rb", ["/some/path/wrong-file.rb", "/some/path/a-file.rb"])).
        to eq("/some/path/a-file.rb")
    end

    it "finds a loaded file with no path and an .so extension when the loaded file has a .so extension" do
      expect(the_probe.require_file("a-file.so", ["/some/path/wrong-file.rb", "/some/path/a-file.so"])).
        to eq("/some/path/a-file.so")
    end

    it "finds a loaded file with a path and no extension when the loaded file has a .rb extension" do
      expect(the_probe.require_file("../a-file", ["/some/path/wrong-file.rb", "/some/path/a-file.rb"])).
        to eq("/some/path/a-file.rb")
    end

    it "finds a loaded file with a path and no extension when the loaded file has a .so extension" do
      expect(the_probe.require_file("../a-file", ["/some/path/wrong-file.rb", "/some/path/a-file.so"])).
        to eq("/some/path/a-file.so")
    end

    it "finds a loaded file with a path and an .rb extension when the loaded file has a .rb extension" do
      expect(the_probe.require_file("../a-file.rb", ["/some/path/wrong-file.rb", "/some/path/a-file.rb"])).
        to eq("/some/path/a-file.rb")
    end

    it "finds a loaded file with a path and an .so extension when the loaded file has a .so extension" do
      expect(the_probe.require_file("../a-file.so", ["/some/path/wrong-file.rb", "/some/path/a-file.so"])).
        to eq("/some/path/a-file.so")
    end

    it "finds the last file loaded" do
      expect(the_probe.require_file("a-file", ["/some/path/a-file.rb", "/some/other/path/a-file.rb"])).
        to eq("/some/other/path/a-file.rb")
    end
  end

And the implementation is:

  def require_file(file, loaded_features)
    base_file= Pathname.new(file).basename.to_s

    if base_file =~ /.*(\.rb|\.so)$/
      match_pattern= /.*\/#{base_file}$/
    else
      match_pattern= /.*\/#{base_file}(\.rb|\.so)$/
    end

    loaded_features.reverse_each do |loaded_file|
      return loaded_file if loaded_file =~ match_pattern
    end

    nil
  end

We first use Pathname#basename strip off any directory component of the requested filename, so we're left with just the filename. Then, we generate a regex from the filename. If the filename already has an extension, then we use a regex which will match exactly that filename, with any directory path in front of it. If, on the other hand, the requested filename doesn't already have an extension, then we use a regex which will match either a .so or a .rb file, again, with any directory path in front of it.

Having set up our regex to match the file we're looking for, we then scan through $LOADED_FEATURES for our file. We start at the end of the array and search backward, because entries are added at the end, so we'll find the one we want more quickly.

And that's the hard work for require and require_relative sorted out.

Finding `load`'d files

Turning to load next, we follow a similar design. This time, our new method is load_file(filename, load_path).

Our tests look like:

  describe "#load_file" do
    before do
      FileUtils.mkdir_p "subdir"
      File.open("subdir/a-file.rb", "w") {|f| f.puts("'junk'")}
    end

    after do
      FileUtils.rm_rf "subdir"
    end

    it "finds the file when the filename is a non-absolute path" do
      expect(the_probe.load_file("subdir/a-file.rb", [])).
        to eq("#{Dir.pwd}/subdir/a-file.rb")
    end

    it "finds the file on the $LOAD_PATH from a non-absolute path" do
      expect(the_probe.load_file("a-file.rb", ["#{Dir.pwd}/subdir"])).
        to eq("#{Dir.pwd}/subdir/a-file.rb")
    end

    it "finds the file from an absolute path" do
      expect(the_probe.load_file("#{Dir.pwd}/subdir/a-file.rb", [])).
        to eq("#{Dir.pwd}/subdir/a-file.rb")
    end
  end

And the implementation is:

  def load_file(filename, load_path)
    loaded_file= File.expand_path(filename)

    if File.exists?(loaded_file)
      return loaded_file
    end

    load_path.each do |path|
      loaded_file= "#{path}/#{filename}"
      if File.exists?(loaded_file)
        return loaded_file
      end
    end

    nil
  end

The actual code to generate our output messages is verbose enough that it clutters the wrappers and makes them harder to follow. So we add two small utility methods which move the details of generating our output messages out of the wrapper:

  def require_message(loaded, file, loaded_features)
    absolute_file= require_file(file, loaded_features)

    if !loaded
      "already loaded"
    elsif absolute_file
      "loaded #{absolute_file}"
    else
      "couldn't find loaded file"
    end
  end

  def load_message(filename, load_path)
    found_file= load_file(filename, load_path)
    if found_file
      "loaded #{found_file}"
    else
      "couldn't find file"
    end
  end

And our install method, with all three wrappers, ends up looking like:

  def install
    wrap(Kernel, :require) do |original_require, args|
      return_value= original_require.call(*args)
      puts "require(#{args.first}): #{require_message(return_value, args.first, $LOADED_FEATURES)}"
      return_value
    end

    wrap(Kernel, :require_relative) do |original_require_relative, args|
      return_value= require("#{caller_directory}/#{args.first}")
      puts "require_relative(#{args.first}): #{require_message(return_value, args.first, $LOADED_FEATURES)}"
      return_value
    end

    wrap(Kernel, :load) do |original_load, args|
      return_value= original_load.call(*args)
      puts "load(#{args.first}): #{load_message(args.first, $LOAD_PATH)}"
      return_value
    end
  end

Running the app: One More Time

So, let's try running our target app again:

jmax@deepthought $ bin/ruby-explorer ../bare-rails/
require(rubygems): already loaded
require(rubygems): already loaded
require(rubygems): already loaded
require(bundler/version): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/version.rb
require(bundler/compatibility_guard): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/compatibility_guard.rb
require(etc): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/x86_64-linux/etc.so
require(bundler/vendor/fileutils/lib/fileutils): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/vendor/fileutils/lib/fileutils.rb
require(bundler/vendored_fileutils): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/vendored_fileutils.rb
  :
  :
require(bundler/remote_specification): already loaded
require(bundler/stub_specification): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/stub_specification.rb
require(bundler/endpoint_specification): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/endpoint_specification.rb
require(bundler/setup): loaded /home/jmax/.rvm/rubies/ruby-2.5.5/lib/ruby/site_ruby/2.5.0/bundler/setup.rb
require_relative(bootsnap/version): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/version.rb
require_relative(bootsnap/bundler): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/bundler.rb
require_relative(../explicit_require): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/explicit_require.rb
require_relative(load_path_cache/path_scanner): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/path_scanner.rb
require_relative(path_scanner): already loaded
require_relative(load_path_cache/path): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/path.rb
require_relative(../explicit_require): already loaded
require_relative(load_path_cache/cache): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/cache.rb
require_relative(../explicit_require): already loaded
require_relative(load_path_cache/store): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/store.rb
require_relative(load_path_cache/change_observer): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/change_observer.rb
require_relative(load_path_cache/loaded_features_index): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/loaded_features_index.rb
require_relative(load_path_cache/realpath_cache): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/realpath_cache.rb
require_relative(bootsnap/load_path_cache): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache.rb
require_relative(bootsnap/compile_cache): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/compile_cache.rb
require_relative(../bootsnap): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap.rb
require_relative(load_path_cache/core_ext/kernel_require): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb
require(/home/jmax/projects/bare-rails/bin/../config/boot): loaded /home/jmax/projects/bare-rails/config/boot.rb
require_relative(../config/boot): loaded /home/jmax/projects/bare-rails/config/boot.rb
=> Booting Puma
=> Rails 6.0.2.2 application starting in development
=> Run `rails server --help` for more startup options
load(/home/jmax/projects/bare-rails/config/initializers/application_controller_renderer.rb): loaded /home/jmax/projects/bare-rails/config/initializers/application_controller_renderer.rb
load(/home/jmax/projects/bare-rails/config/initializers/assets.rb): loaded /home/jmax/projects/bare-rails/config/initializers/assets.rb
load(/home/jmax/projects/bare-rails/config/initializers/backtrace_silencers.rb): loaded /home/jmax/projects/bare-rails/config/initializers/backtrace_silencers.rb
load(/home/jmax/projects/bare-rails/config/initializers/content_security_policy.rb): loaded /home/jmax/projects/bare-rails/config/initializers/content_security_policy.rb
load(/home/jmax/projects/bare-rails/config/initializers/cookies_serializer.rb): loaded /home/jmax/projects/bare-rails/config/initializers/cookies_serializer.rb
load(/home/jmax/projects/bare-rails/config/initializers/filter_parameter_logging.rb): loaded /home/jmax/projects/bare-rails/config/initializers/filter_parameter_logging.rb
load(/home/jmax/projects/bare-rails/config/initializers/inflections.rb): loaded /home/jmax/projects/bare-rails/config/initializers/inflections.rb
load(/home/jmax/projects/bare-rails/config/initializers/mime_types.rb): loaded /home/jmax/projects/bare-rails/config/initializers/mime_types.rb
load(/home/jmax/projects/bare-rails/config/initializers/wrap_parameters.rb): loaded /home/jmax/projects/bare-rails/config/initializers/wrap_parameters.rb
load(/home/jmax/projects/bare-rails/config/routes.rb): loaded /home/jmax/projects/bare-rails/config/routes.rb
load(/home/jmax/.rvm/gems/ruby-2.5.5/gems/actionmailbox-6.0.2.2/config/routes.rb): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/actionmailbox-6.0.2.2/config/routes.rb
load(/home/jmax/.rvm/gems/ruby-2.5.5/gems/activestorage-6.0.2.2/config/routes.rb): loaded /home/jmax/.rvm/gems/ruby-2.5.5/gems/activestorage-6.0.2.2/config/routes.rb
Puma starting in single mode...
* Version 4.3.3 (ruby 2.5.5-p157), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://127.0.0.1:3000
* Listening on tcp://[::1]:3000
Use Ctrl-C to stop

And there we are! A full trace of every file pulled into our target Rails app, with full file paths for every file.

Phew!

John's Free Energy

Exploring Ruby on Rails Projects With Metaprogramming: Running the App