Merge pull request rsim#2727 from yahonda/add-supports-expression-index

Override supports_expression_index? to true

Author: yahonda

lib/active_record/connection_adapters/oracle_enhanced_adapter.rb

@@ -511,6 +511,10 @@ def supports_validate_constraints?
         true
       end
 
+      def supports_expression_index?
+        true
+      end
+
       def supports_optimizer_hints?
         true
       end

spec/active_record/connection_adapters/oracle_enhanced/schema_dumper_spec.rb

@@ -106,6 +106,48 @@ def drop_test_posts_table
     end
   end
 
+  describe "expression index" do
+    before(:each) do
+      schema_define do
+        create_table :test_idx_expr_dump, force: true do |t|
+          t.string :name
+        end
+      end
+    end
+
+    after(:each) do
+      schema_define do
+        drop_table :test_idx_expr_dump, if_exists: true
+      end
+    end
+
+    it "dumps a function-based index with the expression preserved" do
+      schema_define do
+        add_index :test_idx_expr_dump, "LOWER(name)", name: "ix_dump_expr"
+      end
+      output = dump_table_schema "test_idx_expr_dump"
+      expect(output).to match(/t\.index \[.*LOWER\(.*NAME.*\).*\], name: "ix_dump_expr"/im)
+    end
+
+    it "round-trips an expression index through dump and load" do
+      schema_define do
+        add_index :test_idx_expr_dump, "LOWER(name)", name: "ix_rt_expr"
+      end
+      dumped = dump_table_schema "test_idx_expr_dump"
+      schema_define do
+        drop_table :test_idx_expr_dump, if_exists: true
+      end
+      body = dumped[/ActiveRecord::Schema\[.+?\]\.define\(version: \d+\) do\n(.+)\nend\s*\z/m, 1]
+      schema_define { instance_eval(body) }
+      expr = ActiveRecord::Base.lease_connection.select_value(<<~SQL.squish)
+        SELECT column_expression FROM all_ind_expressions
+         WHERE index_owner = SYS_CONTEXT('userenv', 'current_schema')
+           AND index_name = 'IX_RT_EXPR'
+      SQL
+      expect(expr).to match(/LOWER\("?NAME"?\)/i)
+    end
+  end
+
   describe "foreign key constraints" do
     # Recreate the canonical tables before each example. One example
     # (`should include primary_key when reference column name is not 'id'`)

spec/active_record/connection_adapters/oracle_enhanced/schema_statements_spec.rb

@@ -559,6 +559,33 @@ class ::TestEmployee < ActiveRecord::Base; end
       end
     end
 
+    it "supports expression indexes (function-based) via add_index" do
+      schema_define do
+        create_table :test_idx_expr, force: true do |t|
+          t.string :name
+        end
+        add_index :test_idx_expr, "LOWER(name)", name: "ix_expr_lower_name"
+      end
+      idx_count = @conn.select_value(<<~SQL.squish)
+        SELECT COUNT(*) FROM all_indexes
+         WHERE owner = SYS_CONTEXT('userenv', 'current_schema')
+           AND index_name = 'IX_EXPR_LOWER_NAME'
+      SQL
+      expect(idx_count).to eq(1)
+      expr = @conn.select_value(<<~SQL.squish)
+        SELECT column_expression FROM all_ind_expressions
+         WHERE index_owner = SYS_CONTEXT('userenv', 'current_schema')
+           AND index_name = 'IX_EXPR_LOWER_NAME'
+      SQL
+      expect(expr).to match(/LOWER\("?NAME"?\)/i)
+    ensure
+      schema_define { drop_table :test_idx_expr, if_exists: true }
+    end
+
+    it "reports supports_expression_index? as true" do
+      expect(@conn.supports_expression_index?).to be(true)
+    end
+
     it "measures default index name length in bytes, not characters" do
       max = @conn.index_name_length
       # "index_t_on_<col>" fits in `max` characters but overflows in bytes

spec/active_record/connection_adapters/oracle_enhanced/structure_dump_spec.rb

@@ -105,6 +105,14 @@ class ::TestPost < ActiveRecord::Base
       expect(dump).to eq("")
     end
 
+    it "dumps a function-based index expression in structure_dump_indexes" do
+      schema_define do
+        add_index :test_posts, "LOWER(title)", name: "ix_struct_expr"
+      end
+      dump = @conn.structure_dump_indexes("test_posts").join("\n")
+      expect(dump).to match(/CREATE INDEX "?IX_STRUCT_EXPR"? ON "?TEST_POSTS"? \(LOWER\("?TITLE"?\)\)/i)
+    end
+
     it "appends NOVALIDATE for foreign keys added with validate: false" do
       schema_define do
         add_column :test_posts, :foo_uniq, :integer