meteor: strong typings for mongo collections selectors and modifiers

[andrei-markeev]

Rationale

Personally was struggling for a long time with the lack of intellisense in Mongo selectors and modifiers. This prevents efficient refactoring of data model. Using mapped and conditional types from TypeScript 2.8 I finally managed to solve this problem, and all selectors except composite (e.g. "arr.$.prop") are now covered by intellisense. Thanks to this change I was able to spot couple of serious bugs in a production application I am developing.

Checklist

• Use a meaningful title for the pull request. Include the name of the package modified.

• Test the change in your own code. (Compile and run.)

• Add or edit tests to reflect the change. (Run with npm test.)

• Follow the advice from the readme.

• Avoid common mistakes.

• Run npm run lint package-name (or tsc if no tslint.json is present).

• Provide a URL to documentation or source code which provides context for the suggested changes: https://docs.mongodb.com/manual/reference/

• Increase the version number in the header if appropriate.

• If you are making substantial changes, consider adding a tslint.json containing { "extends": "dtslint/dt.json" }.

[typescript-bot]

@andrei-markeev Thank you for submitting this PR!

🔔 @pgrm @barbatus @fullflavedave @orefalo @dagatsoin @birkskyum @ardatan @stefanholzapfel @vangorra @mattmm3d - please review this PR in the next few days. Be sure to explicitly select Approve or Request Changes in the GitHub UI so I know what's going on.

If no reviewer appears after a week, a DefinitelyTyped maintainer will review the PR instead.

[ardatan]

Thanks for this great enhancements!
Does this update satisfy the usage?

// (obj: { attr })
Collection.find({
'obj.attr': value
})

[andrei-markeev]

Yes, it does, note the & Dictionary<any> in the definitions. But when using this syntax, obviously there won't be any good intellisense.

As you can see on the screenshots below, find that uses 'inlineLinks.objectType' passes validation alright, while still preserving correct intellisense when using authorId or other properties.

[ardatan]

Yes, you're right, it's my fault. Sorry for that.
Thank you again for this great update!
It looks good to me!

[typescript-bot]

A definition owner has approved this PR ⭐️. A maintainer will merge this PR shortly. If it shouldn't be merged yet, please leave a comment saying so and we'll wait. Thank you for your contribution to DefinitelyTyped!

[ardatan]

Hello, many people are using these typings for Angular-Meteor projects, then they are facing some problems because Angular uses TypeScript 2.7.2. So is it possible to make it compatible?

[andrei-markeev]

Conditional and mapped types are supported only starting from TS 2.8... the only option to make those compatible seems to be roll back the MongoDb intellisense completely and wait until Angular upgrades to TS 2.8+...