Index field looses date precision if type not explicitly set to date (and causes sync to always update all documents)

[gabriel]

Expected behavior

field :updated_at should store date with microseconds, e.g. 2022-07-20T02:00:08.123456Z

Actual behavior

field :updated_at stores date with milliseconds, e.g. 2022-07-20T02:00:08.123Z
field :updated_at, type: "date" correctly stores date with microseconds

This causes chewy:sync to always show all documents as outdated (the match fails on the microsecond to millisecond comparison, unless the microseconds actually happens to be 000).

Steps to reproduce the problem

To view bug:

• Specify index with field :updated_at.
• rake chewy:reset
• View a document and see it only has millisecond precision
• rake chewy:sync (updates all documents)
• rake chewy:sync (updates all documents again)

To view workaround:

• Specify index with field :updated_at, type: "date".
• rake chewy:reset
• View a document and see it correctly has microsecond precision
• rake chewy:sync (no updates)
• rake chewy:sync (no updates)

Version Information

Share here essential version information such as:

• Chewy version: 7.2.6
• Elasticsearch version: 8.3.3
• Ruby version: 3.1.2p20
• Rails version: 7.0.3.1