35 lines
1.3 KiB
Ruby
35 lines
1.3 KiB
Ruby
# frozen_string_literal: true
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# Sometimes data migration specs require adding invalid test data in order to test
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# the migration (e.g. adding a row with null foreign key). Certain db migrations that
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# add constraints (e.g. NOT NULL constraint) prevent invalid records from being added
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# and data migration from being tested. For this reason, SchemaVersionFinder can be used
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# to find and use schema prior to specified one.
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#
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# @example
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# RSpec.describe CleanupThings, :migration, schema: MigrationHelpers::SchemaVersionFinder.migration_prior(AddNotNullConstraint) do ...
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#
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# SchemaVersionFinder returns schema version prior to the one specified, which allows to then add
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# invalid records to the database, which in return allows to properly test data migration.
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module MigrationHelpers
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class SchemaVersionFinder
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def self.migrations_paths
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ActiveRecord::Migrator.migrations_paths
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end
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def self.migration_context
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ActiveRecord::MigrationContext.new(migrations_paths, ActiveRecord::SchemaMigration)
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end
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def self.migrations
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migration_context.migrations
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end
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def self.migration_prior(migration_klass)
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migrations.each_cons(2) do |previous, migration|
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break previous.version if migration.name == migration_klass.name
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end
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end
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end
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end
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