fix(import): COMPASS-4206: Fix type detection and export formatting.

[imlucas]

Description

• fix(import): COMPASS-4206: Make type detection/casting work right when importing/exporting .json. a093933
• feat(export): Pick up nested objects to include in projection f6baf06

doc = {
  _id: 'Arlo', 
  location: {
    place: 'home',
    activity: {
       sleeping: true,
       is: 'on the couch'
    }
};

Before this would populate the projection as:

• _id
• location

Now you can specify full paths for more control over what is actually returned:

• _id
• location.place
• location.activity.is
• location.activity.sleeping

Use case: (See a 1M line csv imported that is 300 fields wide and you only want 2).

• fix(export): Add tests to make sure csv's have correct headers. df70ff9

• fix(export): Headers should be dotnotation for nested object paths.

Testing

Dicogs CSV

https://www.npmjs.com/package/discogs-data-tools

mongoexport CSV of all label names in the dicogs database:

BitTorrent Data Set CSV

Andy Pavlo's BitTorrent Data Set

Export test.people with only address.city

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

• fix(import): COMPASS-4206: Fix type detection and export formatting. compass-import-export#144
• fix(import): COMPASS-4206: transform should not recurse keys of a bson value compass-import-export#146

Types of changes

• Backport Needed

• Patch (non-breaking change which fixes an issue)

• Minor (non-breaking change which adds functionality)

• Major (fix or feature that would cause existing functionality to change)

[imlucas]

Backported to 1.21-releases 39d0ad9