Set error code to 1 if generator could not be found (rails#53028)

railties/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Exit `rails g` with code 1 if generator could not be found.
+
+    Previously `rails g` returned 0, which would make it harder to catch typos in scripts calling `rails g`.
+
+    *Christopher Özbek*
+
 *   Remove `require_*` statements from application.css to align with the transition from Sprockets to Propshaft.
 
     With Propshaft as the default asset pipeline in Rails 8, the require_tree and require_self clauses in application.css are no longer necessary, as they were specific to Sprockets. Additionally, the comment has been updated to clarify that CSS precedence now follows standard cascading order without automatic prioritization by the asset pipeline.

railties/lib/rails/generators.rb

@@ -272,6 +272,7 @@ def invoke(namespace, args = ARGV, config = {})
             #{error.detailed_message}
             Run `bin/rails generate --help` for more options.
           MSG
+          exit 1
         end
       end
 

railties/test/generators_test.rb

@@ -25,15 +25,23 @@ def test_simple_invoke
 
   def test_invoke_when_generator_is_not_found
     name = :unknown
-    output = capture(:stdout) { Rails::Generators.invoke name }
+    output = capture(:stdout) {
+      assert_raises SystemExit do
+        Rails::Generators.invoke name
+      end
+    }
     assert_match "Could not find generator '#{name}'.", output
     assert_match "`bin/rails generate --help`", output
     assert_no_match "Did you mean", output
   end
 
   def test_generator_suggestions
     name = :migrationz
-    output = capture(:stdout) { Rails::Generators.invoke name }
+    output = capture(:stdout) {
+      assert_raises SystemExit do
+        Rails::Generators.invoke name
+      end
+    }
     assert_match "Did you mean?  migration", output
   end
 
@@ -43,7 +51,11 @@ def test_generator_suggestions_except_en_locale
     I18n.available_locales = :ja
     I18n.default_locale = :ja
     name = :tas
-    output = capture(:stdout) { Rails::Generators.invoke name }
+    output = capture(:stdout) {
+      assert_raises SystemExit do
+        Rails::Generators.invoke name
+      end
+    }
     assert_match "Did you mean?  task", output
   ensure
     I18n.available_locales = orig_available_locales