From 5f6efdab0f9acef8d04ca9a018667bfcd1cf59b5 Mon Sep 17 00:00:00 2001
From: Lachlan Sylvester <lachlan.sylvester@3plearning.com>
Date: Wed, 6 Sep 2023 18:42:29 +1000
Subject: [PATCH] dump PostgreSQL schemas as part of the schema dump

---
 activerecord/CHANGELOG.md                             |  4 ++++
 .../connection_adapters/postgresql/schema_dumper.rb   | 11 +++++++++++
 activerecord/lib/active_record/schema_dumper.rb       |  5 +++++
 .../test/cases/adapters/postgresql/schema_test.rb     |  9 +++++++++
 4 files changed, 29 insertions(+)

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index d47582528c..271be0c676 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Dump PostgreSQL schemas as part of the schema dump.
+
+    *Lachlan Sylvester*
+
 ## Rails 7.1.0.beta1 (September 13, 2023) ##
 
 *   Encryption now supports `support_unencrypted_data` being set per-attribute.
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
index a565be72a2..c33f686fba 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
@@ -28,6 +28,17 @@ def types(stream)
             end
           end
 
+          def schemas(stream)
+            schema_names = @connection.schema_names - ["public"]
+
+            if schema_names.any?
+              schema_names.sort.each do |name|
+                stream.puts "  create_schema #{name.inspect}"
+              end
+              stream.puts
+            end
+          end
+
           def exclusion_constraints_in_create(table, stream)
             if (exclusion_constraints = @connection.exclusion_constraints(table)).any?
               add_exclusion_constraint_statements = exclusion_constraints.map do |exclusion_constraint|
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 50f87d9f08..e80266200e 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -57,6 +57,7 @@ def generate_options(config)
 
     def dump(stream)
       header(stream)
+      schemas(stream)
       extensions(stream)
       types(stream)
       tables(stream)
@@ -119,6 +120,10 @@ def extensions(stream)
       def types(stream)
       end
 
+      # schemas are only supported by PostgreSQL
+      def schemas(stream)
+      end
+
       def tables(stream)
         sorted_tables = @connection.tables.sort
 
diff --git a/activerecord/test/cases/adapters/postgresql/schema_test.rb b/activerecord/test/cases/adapters/postgresql/schema_test.rb
index 2053e97bd5..e52ee907be 100644
--- a/activerecord/test/cases/adapters/postgresql/schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/schema_test.rb
@@ -17,6 +17,7 @@ def with_schema_search_path(schema_search_path)
 
 class SchemaTest < ActiveRecord::PostgreSQLTestCase
   include PGSchemaHelper
+  include SchemaDumpingHelper
   self.use_transactional_tests = false
 
   SCHEMA_NAME = "test_schema"
@@ -487,6 +488,14 @@ def test_rename_index
     assert @connection.index_name_exists?("#{SCHEMA_NAME}.#{TABLE_NAME}", new_name)
   end
 
+  def test_dumping_schemas
+    output = dump_all_table_schema(/./)
+
+    assert_no_match %r{create_schema "public"}, output
+    assert_match %r{create_schema "test_schema"}, output
+    assert_match %r{create_schema "test_schema2"}, output
+  end
+
   private
     def columns(table_name)
       @connection.send(:column_definitions, table_name).map do |name, type, default|