Merge pull request rails#54960 from flavorjones/flavorjones/stable-sort-schema-cache

Sort schema cache columns and indexes per table when dumping

Author: byroot

activerecord/lib/active_record/connection_adapters/schema_cache.rb

@@ -271,10 +271,10 @@ def initialize_dup(other) # :nodoc:
       end
 
       def encode_with(coder) # :nodoc:
-        coder["columns"]          = @columns.sort.to_h
+        coder["columns"]          = @columns.sort.to_h.transform_values { _1.sort_by(&:name) }
         coder["primary_keys"]     = @primary_keys.sort.to_h
         coder["data_sources"]     = @data_sources.sort.to_h
-        coder["indexes"]          = @indexes.sort.to_h
+        coder["indexes"]          = @indexes.sort.to_h.transform_values { _1.sort_by(&:name) }
         coder["version"]          = @version
       end
 

activerecord/test/cases/connection_adapters/schema_cache_test.rb

@@ -467,22 +467,26 @@ def test_when_lazily_load_schema_cache_is_set_cache_is_lazily_populated_when_est
         values = [["z", nil], ["y", nil], ["x", nil]]
         expected = values.sort.to_h
 
+        named = Struct.new(:name)
+        named_values = [["z", [named.new("c"), named.new("b")]], ["y", [named.new("c"), named.new("b")]], ["x", [named.new("c"), named.new("b")]]]
+        named_expected = named_values.sort.to_h.transform_values { _1.sort_by(&:name) }
+
         coder = {
-          "columns" => values,
+          "columns" => named_values,
           "primary_keys" => values,
           "data_sources" => values,
-          "indexes" => values,
+          "indexes" => named_values,
           "deduplicated" => true
         }
 
         schema_cache = SchemaCache.allocate
         schema_cache.init_with(coder)
         schema_cache.encode_with(coder)
 
-        assert_equal expected, coder["columns"]
+        assert_equal named_expected, coder["columns"]
         assert_equal expected, coder["primary_keys"]
         assert_equal expected, coder["data_sources"]
-        assert_equal expected, coder["indexes"]
+        assert_equal named_expected, coder["indexes"]
         assert coder.key?("version")
       end