feat: make snack count available to the consumers

src/SnackbarContext.ts

@@ -8,4 +8,5 @@ const noOp = () => {
 export default React.createContext<ProviderContext>({
     enqueueSnackbar: noOp,
     closeSnackbar: noOp,
+    snackCount: 0
 });

src/SnackbarProvider/SnackbarProvider.tsx

@@ -50,6 +50,7 @@ class SnackbarProvider extends Component<SnackbarProviderProps, State> {
             contextValue: {
                 enqueueSnackbar: this.enqueueSnackbar.bind(this),
                 closeSnackbar: this.closeSnackbar.bind(this),
+                snackCount: this.state.snacks.length
             },
         };
     }

src/types.ts

@@ -406,6 +406,7 @@ interface EnqueueSnackbar {
 export interface ProviderContext {
     enqueueSnackbar: EnqueueSnackbar;
     closeSnackbar: (key?: SnackbarKey) => void;
+    snackCount: number
 }
 
 export declare class SnackbarProvider extends React.Component<SnackbarProviderProps> {