State of the TypeScript migration

[nunomaduro]

Hey team, the goal of this discussion is share thoughts of the TypeScript migration.

Jira Task: IFW-1152
This need to reviewed, tested, and merged: #4408.
Current content migrated: 45%. The more complicated connectors/widgets are done.

The amount of time needed to migrated the remaining 55% it may take 4 weeks of work. It's easy task, but very time consuming to do it right.

Note that, this migration is focus on the public API of connectors/widgets, and not on making internals strict.

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How to migrate a connector/widget

1. Connector & Connector Tests

First, you migrate the entire connector folder. Keep in mind,
that for each connector you need to export:

- The default function with the name: **connect{Name}** and his type **{Name}Connector**.
- The **{Name}RendererOptions** type and its used types.
- The **{Name}ConnectorParams** type and its used types.

2. Widget & Widgets Tests

Next, you migrate the entire widget folder. Keep in mind,
that for each widget you need to export:

- The default function with the name: **{name}** and his type **{Name}Widget**.
- The **{Name}WidgetOptions** type, and its used types.
- Optionally the **{Name}Templates** type and its used types.
- Optionally the **{Name}CSSClasses** type and its used types.

3. Stories

Finally, you need to upgrade the stories to used the typed
widget/connectors replacing:

+ import { {name} } from '../../src/widgets';

search.addWidgets([
-  instantsearch.widgets.{name}({ ..
+  {name}({ ..

[francoischalifour]

Thanks for bootstrapping this task.

To add on the migration process: if you feel adventurous, you can also migrate the Preact components 🙂