feat: hide isHidden challenges

client/src/components/Map/components/SuperBlock.js

@@ -60,9 +60,12 @@ export class SuperBlock extends Component {
     const blocksForSuperBlock = nodes.filter(
       node => node.superBlock === superBlock
     );
+    // since the nodes have been filtered based on isHidden, any blocks whose
+    // nodes have been entirely removed will not appear in this array.
     const blockDashedNames = uniq(
       blocksForSuperBlock.map(({ block }) => block)
     );
+    // render all non-empty blocks
     return (
       <ul>
         {blockDashedNames.map(blockDashedName => (

client/src/components/Map/index.js

@@ -111,6 +111,8 @@ export class Map extends Component {
 
   render() {
     const { nodes } = this.props;
+    // if a given superBlock's nodes have been filtered (via isHidden, say) that
+    // superBlock will not appear in superBlocks and will not be rendered.
     const superBlocks = uniq(nodes.map(({ superBlock }) => superBlock));
     return (
       <Row>