Merge pull request #26343 from ccutrer/runner_from_stdin

support `-` as an argument to `rails runner`

4 files changed, 20 insertions, 2 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index f720b7caab..45e1f5f3ea 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Support `-` as a platform-agnostic way to run a script from stdin with
+    `rails runner`
+
+    *Cody Cutrer*
+
 *   Add `bootsnap` to default `Gemfile`.
 
     *Burke Libbey*
diff --git a/railties/lib/rails/commands/runner/USAGE b/railties/lib/rails/commands/runner/USAGE
index b2a6e8493d..24b60037f0 100644
--- a/railties/lib/rails/commands/runner/USAGE
+++ b/railties/lib/rails/commands/runner/USAGE
@@ -8,6 +8,9 @@ Run the Ruby file located at `path/to/filename.rb` after loading the app:
 
   <%= executable %> path/to/filename.rb
 
+Run the Ruby script read from stdin after loading the app:
+  <%= executable %> -
+
 <% unless Gem.win_platform? %>
 You can also use the runner command as a shebang line for your executables:
 
diff --git a/railties/lib/rails/commands/runner/runner_command.rb b/railties/lib/rails/commands/runner/runner_command.rb
index 6864a9726b..c931fc2152 100644
--- a/railties/lib/rails/commands/runner/runner_command.rb
+++ b/railties/lib/rails/commands/runner/runner_command.rb
@@ -13,7 +13,7 @@ module Rails
       end
 
       def self.banner(*)
-        "#{super} [<'Some.ruby(code)'> | <filename.rb>]"
+        "#{super} [<'Some.ruby(code)'> | <filename.rb> | -]"
       end
 
       def perform(code_or_file = nil, *command_argv)
@@ -29,7 +29,9 @@ module Rails
 
         ARGV.replace(command_argv)
 
-        if File.exist?(code_or_file)
+        if code_or_file == "-"
+          eval($stdin.read, binding, "stdin")
+        elsif File.exist?(code_or_file)
           $0 = code_or_file
           Kernel.load code_or_file
         else
diff --git a/railties/test/application/runner_test.rb b/railties/test/application/runner_test.rb
index 0c45bc398a..81f717b2c3 100644
--- a/railties/test/application/runner_test.rb
+++ b/railties/test/application/runner_test.rb
@@ -84,6 +84,14 @@ module ApplicationTests
       assert_match %w( a b ).to_s, Dir.chdir(app_path) { `bin/rails runner "bin/program_name.rb" a b` }
     end
 
+    def test_should_run_stdin
+      app_file "bin/count_users.rb", <<-SCRIPT
+      puts User.count
+      SCRIPT
+
+      assert_match "42", Dir.chdir(app_path) { `cat bin/count_users.rb | bin/rails runner -` }
+    end
+
     def test_with_hook
       add_to_config <<-RUBY
         runner do |app|