Run CI with GitHub Actions to support Oracle database 18c

[yahonda]

This pull request runs CI with GitHub Actions.

• Run Oracle Database 18c
• Only CRuby versions executed since due to Use Ubuntu Xenial at Travis CI #176
• No Active Record matrix added yet
• Use dbms_session.sleep for Oracle Database 18c or higher
• Skip "using Oracle 9.2" for Oracle Database 18c or higher

[yahonda]

dbms_session.sleep may be a better option to address this error.

  2) ActiveRecord connection should safely close cursors in threaded environment
     Failure/Error: raise ArgumentError, "No database object '#{method.to_s.upcase}' found" unless object

     ArgumentError:
       No database object 'DBMS_LOCK' found
     # ./lib/plsql/schema.rb:182:in `method_missing'
     # ./spec/plsql/schema_spec.rb:233:in `block (4 levels) in <top (required)>'

https://oracle-base.com/articles/18c/dbms_session-sleep-18c

[yahonda]

The remaining failure.

Failures:

  1) Parameter type mapping / Function with table indexed by bynary integer parameter using Oracle 9.2 should create temporary tables when using Oracle 9.2
     Failure/Error: case element_metadata[:data_type]

     NoMethodError:
       undefined method `[]' for nil:NilClass
     # ./lib/plsql/procedure.rb:314:in `block in ensure_tmp_tables_created'
     # ./lib/plsql/procedure.rb:311:in `each'
     # ./lib/plsql/procedure.rb:311:in `ensure_tmp_tables_created'
     # ./lib/plsql/procedure_call.rb:15:in `initialize'
     # ./lib/plsql/procedure.rb:545:in `new'
     # ./lib/plsql/procedure.rb:545:in `exec'
     # ./lib/plsql/package.rb:67:in `method_missing'
     # ./spec/plsql/procedure_spec.rb:1522:in `block (4 levels) in <top (required)>'

Finished in 44.29 seconds (files took 0.56531 seconds to load)
453 examples, 1 failure, 3 pending

Failed examples:

rspec ./spec/plsql/procedure_spec.rb:1521 # Parameter type mapping / Function with table indexed by bynary integer parameter using Oracle 9.2 should create temporary tables when using Oracle 9.2

[yahonda]

I've got reason why it fails against Oracle database 18c.

This spec simulates the connection as if it connects to Oracle database 9.2.

ruby-plsql/spec/plsql/procedure_spec.rb

Lines 1512 to 1514 in 4c33681

	# simulate Oracle 9.2 connection
	plsql(:oracle_9).connection = get_connection
	allow(plsql(:oracle_9).connection).to receive(:database_version).and_return([9, 2, 0, 0])

Then get_argument_metadata executes get_argument_metadata_below_18c.

ruby-plsql/lib/plsql/procedure.rb

Lines 85 to 91 in 4c33681

	def get_argument_metadata #:nodoc:
	if (@schema.connection.database_version <=> [18, 0, 0, 0]) >= 0
	get_argument_metadata_from_18c
	else
	get_argument_metadata_below_18c
	end
	end

Both get_argument_metadata_from_18c and get_argument_metadata_below_18c methods depend on each Oracle database dictionary implentation then only mocking database version is not enough.

I'm going to skip this test if the database version is higher than 18c.

Failures:

  1) Parameter type mapping / Function with table indexed by bynary integer parameter using Oracle 9.2 should create temporary tables when using Oracle 9.2
     Failure/Error: case element_metadata[:data_type]

     NoMethodError:
       undefined method `[]' for nil:NilClass
     # ./lib/plsql/procedure.rb:314:in `block in ensure_tmp_tables_created'
     # ./lib/plsql/procedure.rb:311:in `each'
     # ./lib/plsql/procedure.rb:311:in `ensure_tmp_tables_created'
     # ./lib/plsql/procedure_call.rb:15:in `initialize'
     # ./lib/plsql/procedure.rb:545:in `new'
     # ./lib/plsql/procedure.rb:545:in `exec'
     # ./lib/plsql/package.rb:67:in `method_missing'
     # ./spec/plsql/procedure_spec.rb:1522:in `block (4 levels) in <top (required)>'

Finished in 44.29 seconds (files took 0.56531 seconds to load)
453 examples, 1 failure, 3 pending

Failed examples:

rspec ./spec/plsql/procedure_spec.rb:1521 # Parameter type mapping / Function with table indexed by bynary integer parameter using Oracle 9.2 should create temporary tables when using Oracle 9.2

[yahonda]

CI failure against Rails main branch is due to rails/rails#42773, at least not relevant to this pull request.