The type of the `endArrow`, `startArrow` and `shape` properties in
`CellStateStyle` were too strict. They prevented to
use custom registered shapes in the style configuration without using a
cast.
Markers of the arrow and custom shapes can be registered by using
methods in `MarkerShape` and `CellRenderer` respectively.
The key to identify the shapes is a string so the types of the
properties in `CellStateStyle` now allow `string` as well.
These offer both the type guidance for standard maxGraph registered
shapes (via a dedicated type) and the extensibility
for custom shapes.
`StyleSheet.getCellStyle` didn't keep the properties of the default
style when `baseStyleNames` was set in the `cellStyle` parameter.
The JSDoc was incorrect (it came from mxGraph) about how the style is
computed, in particular about the default style. It probably leads to
the erroneous implementation during migration. It is now fixed and
clearly describe the rules followed to merge style properties.
The 'Stylesheet' story has been updated to correctly use the maxGraph
API. It also includes more examples involving `baseStyleNames` to
show the 'properties merge' in action.
The `align` and `verticalAlign` values passed to the constructor weren't
set, so the overlay position was always set to
the default one.
The `align` and `verticalAlign` properties are now using the AlignValue
and VAlignValue types respectively instead of
defining inline types. This improves the consistent in the whole code.
To demonstrate the fix, the Overlays story now set 'align' and
'verticalAlign' randomly.
Also introduce `jest` to test the fix and the whole
implementation of the changed method. Types check support is provided by
`ts-jest`. As maxGraph uses a lot of browser objects, also setup
`jest-jsdom-environment`.