discourse/spec/components/migration/column_dropper_spec.rb
Guo Xiang Tan 40fa96777d
FEATURE: Post deployment migrations. (#6406)
This moves us away from the delayed drops pattern which
was problematic on two counts. First, it uses a hardcoded "delay for"
duration which may be too short for certain deployment strategies.
Second, delayed drop doesn't ensure that it only runs after
the latest application code has been deployed. If the migration runs
and the application code fails to deploy, running the migration after
"delay for" has been met will cause the application to blow up.

The new strategy allows post deployment migrations to be skipped if the
env `SKIP_POST_DEPLOYMENT_MIGRATIONS` is provided.

```
SKIP_POST_DEPLOYMENT_MIGRATIONS=1 rake db:migrate
-> deploy app servers
SKIP_POST_DEPLOYMENT_MIGRATIONS=0 rake db:migrate
```

To aid with the generation of a post deployment migration, a generator
has been added. Simply run `rails generate post_migration`.
2018-10-08 15:47:38 +08:00

126 lines
3.2 KiB
Ruby

require 'rails_helper'
require_dependency 'migration/column_dropper'
RSpec.describe Migration::ColumnDropper do
def has_column?(table, column)
DB.exec(<<~SQL, table: table, column: column) == 1
SELECT 1
FROM INFORMATION_SCHEMA.COLUMNS
WHERE
table_schema = 'public' AND
table_name = :table AND
column_name = :column
SQL
end
describe ".execute_drop" do
let(:columns) { %w{junk junk2} }
before do
columns.each do |column|
DB.exec("ALTER TABLE topics ADD COLUMN #{column} int")
end
end
after do
columns.each do |column|
DB.exec("ALTER TABLE topics DROP COLUMN IF EXISTS #{column}")
end
end
it "drops the columns" do
Migration::ColumnDropper.execute_drop("topics", columns)
columns.each do |column|
expect(has_column?('topics', column)).to eq(false)
end
end
end
describe '.mark_readonly' do
let(:table_name) { "table_with_readonly_column" }
before do
DB.exec <<~SQL
CREATE TABLE #{table_name} (topic_id INTEGER, email TEXT);
INSERT INTO #{table_name} (topic_id, email)
VALUES (1, 'something@email.com');
SQL
Migration::ColumnDropper.mark_readonly(table_name, 'email')
end
after do
ActiveRecord::Base.connection.reset!
DB.exec <<~SQL
DROP TABLE IF EXISTS #{table_name};
DROP FUNCTION IF EXISTS #{Migration::BaseDropper.readonly_function_name(table_name, 'email')} CASCADE;
SQL
end
it 'should be droppable' do
Migration::ColumnDropper.execute_drop(table_name, ['email'])
expect(has_trigger?(Migration::BaseDropper.readonly_trigger_name(
table_name, 'email'
))).to eq(false)
expect(has_column?(table_name, 'email')).to eq(false)
end
it 'should prevent updates to the readonly column' do
begin
DB.exec <<~SQL
UPDATE #{table_name}
SET email = 'testing@email.com'
WHERE topic_id = 1;
SQL
rescue PG::RaiseException => e
[
"Discourse: email in #{table_name} is readonly",
'discourse_functions.raise_table_with_readonly_column_email_readonly()'
].each do |message|
expect(e.message).to include(message)
end
end
end
it 'should allow updates to the other columns' do
DB.exec <<~SQL
UPDATE #{table_name}
SET topic_id = 2
WHERE topic_id = 1
SQL
expect(
ActiveRecord::Base.exec_sql("SELECT * FROM #{table_name};").values
).to include([2, "something@email.com"])
end
it 'should prevent insertions to the readonly column' do
expect do
ActiveRecord::Base.connection.raw_connection.exec <<~SQL
INSERT INTO #{table_name} (topic_id, email)
VALUES (2, 'something@email.com');
SQL
end.to raise_error(
PG::RaiseException,
/Discourse: email in table_with_readonly_column is readonly/
)
end
it 'should allow insertions to the other columns' do
DB.exec <<~SQL
INSERT INTO #{table_name} (topic_id)
VALUES (2);
SQL
expect(
DB.query_single("SELECT topic_id FROM #{table_name} WHERE topic_id = 2")
).to eq([2])
end
end
end