[DataGrid] Add support for generic types in GridRowParams, GridCellParams, GridRenderCellParams

[ZeeshanTamboli]

Exploring generics for some row and cell types.

Related to issue #1329 (maybe closes this?), issue #545

By passing generic types, we can type value, formattedValue, getValue return type and row in GridRenderCellParams.

For onRowXXXX handlers, row is typed:

Need early feedback and how we can go further.

TODO:

• test_static is failing. I tried auto generating docs, it created wrong docs with generics. I think we need to support generics in the docs api script.

[flaviendelangle]

Suggested change

	export interface GridRenderCellParams<T = any, RowType = any> extends GridCellParams<T, RowType> {
	-export interface GridRenderCellParams<T = any, RowType = any> extends GridCellParams<T, RowType> {
	+export interface GridRenderCellParams<T extends GridCellValue = GridCellValue, RowType = any> extends GridCellParams<T, RowType> {

[flaviendelangle]

In another PR, we should add the RowType generic to GridApi

[ZeeshanTamboli]

I have to still work on fixing the script to correctly generate the correct docs for generic types. Will be working on it.

[ZeeshanTamboli]

I have to still work on fixing the script to correctly generate the correct docs for generic types. Will be working on it.

Looks like typedoc does not support documenting generic types in the way we want to do. I looked into the buildApi script and it seems we have the script for generics but it does not work as expected.

eg: For GridCellParams with row supporting generics to type row data:

 export interface GridCellParams<
  T = GridCellValue,
  RowType extends GridRowDefaultData = GridRowDefaultData,
> {
 --
 --
  value: T;
  /**
   * The cell value formatted with the column valueFormatter.
   */
  formattedValue: T;
  /**
   * The row model of the row that the current cell belongs to.
   */
  row: GridRowModel<RowType>;
 --
 --
}

Script which executes for reference type:
https://github.com/mui-org/material-ui-x/blob/e6cae75d7a49e889d063dba7af741503e2b240d6/docs/scripts/buildApi.ts#L49-L56

The type.type here for row is a reference which makes sense. But it is not detecting type.typeArguments for GridRowModel<RowType>. It is undefined.

The script is instead generating,
| row | RowType | The row model of the row that the current cell belongs to. |

Same is happening for other types and for some it is picking only default generic type in the docs.

I checked into core repo for reference but there is nothing I can find to help me.

@m4theushw Do you have any idea? You can try running docs:api script in this PR and see the generated docs.

[m4theushw]

I added some TS tests and fixed the docs. In the end, I had to use a bunch of any because we though that we were doing the right thing but with the tests I realized that developers wouldn't be able to use the generics.

[ZeeshanTamboli]

Thanks @m4theushw for pushing it further. I have also pushed two commits to improve the docs by leveraging generics.