docs: add JSDoc to CellStyle.baseStyleNames (#222)

packages/core/src/types.ts

@@ -38,7 +38,23 @@ export type Properties = {
   [k: string]: any;
 };
 
-export type CellStyle = CellStateStyle & { baseStyleNames?: string[] };
+export type CellStyle = CellStateStyle & {
+  /**
+   * Names of styles used to fill properties before applying the specific properties defined in {@link CellStateStyle}.
+   *
+   * Here's the initial algorithm for populating properties:
+   * - Take the style name in order from the table
+   * - Retrieve the style associated with the style registered in {@link StyleSheet}.
+   * Ignore unknown styles
+   * - Merge the current style with the style retrieved from `StyleSheet`.
+   *
+   * Once the initial population of properties is complete, merge the style with the properties defined {@link CellStateStyle}.
+   *
+   **NOTE**: the order of styles in the array is important: if the same property is defined in several styles,
+   * the value actually used is that defined in the last style declared in the array.
+   */
+  baseStyleNames?: string[];
+};
 
 export type CellStateStyle = {
   /**

packages/core/src/view/style/Stylesheet.ts

@@ -184,10 +184,10 @@ export class Stylesheet {
       // creates style with the given baseStyleNames. (merges from left to right)
       style = cellStyle.baseStyleNames.reduce(
         (acc, styleName) => {
-          return (acc = {
+          return {
             ...acc,
             ...this.styles.get(styleName),
-          });
+          };
         },
         { ...defaultStyle }
       );