test(event): Move more event store tests to shared_examples

[groyoh]

Context

b3131f4 introduced a shared_examples to improve consistency between the event stores tests. The following methods were not tested in the shared_examples though:

• prorated_events_values
• prorated_sum
• grouped_prorated_sum
• weighted_sum
• grouped_weighted_sum
• prorated_unique_count
• grouped_prorated_unique_count
• prorated_unique_count_breakdown

Furthermore, the weighted_sum_breakdown method was not tested.

Description

This moves the following methods tests to the shared_examples:

• prorated_events_values
• prorated_sum
• grouped_prorated_sum
• weighted_sum
• grouped_weighted_sum

Tests were also added for the weighted_sum_breakdown method.

It looks like the behavior of the prorated unique count methods actually differs from the Postgres and Clickhouse stores so they were not moved to the shared_examples.

This also fixes an issue with the weighted_sum_breakdown method of the Clickhouse store which returned the second_duration as string rather than int. That's because date_diff actually returns an Int64 and ActiveRecord transform that into a String so we call #to_i to ensure consistency between implementations:

lago-api(staging)> Clickhouse::BaseRecord.connection.select_one("SELECT 1::Int64")
=> {"CAST('1', 'Int64')" => "1"}
lago-api(staging)> Clickhouse::BaseRecord.connection.select_one("SELECT 1::Int32")
=> {"CAST('1', 'Int32')" => 1}

Note that the weighted_sum_breakdown method of the Clickhouse stores returns timestamps with a 5 decimal precision rather than 3 as in the other methods.

[ancorcruz]

looks good.

[groyoh]

Thanks for the review @ancorcruz 🙏