feat: add support for next_steps array in mdx frontmatter

Author: a-hariti

src/components/pageGrid.tsx

@@ -1,7 +1,10 @@
+import path from 'path';
+
 import Link from 'next/link';
 
-import {nodeForPath} from 'sentry-docs/docTree';
+import {DocNode, nodeForPath} from 'sentry-docs/docTree';
 import {serverContext} from 'sentry-docs/serverContext';
+import {isTruthy} from 'sentry-docs/utils';
 
 type Props = {
   nextPages: boolean;
@@ -14,21 +17,27 @@ type Props = {
 };
 
 export function PageGrid({header}: Props) {
-  const {rootNode, path} = serverContext();
+  const {rootNode, path: nodePath} = serverContext();
   if (!rootNode) {
     return null;
   }
 
-  const parentNode = nodeForPath(rootNode, path);
+  const parentNode = nodeForPath(rootNode, nodePath);
   if (!parentNode || parentNode.children.length === 0) {
     return null;
   }
 
+  const children: DocNode[] = parentNode.frontmatter.next_steps?.length
+    ? (parentNode.frontmatter.next_steps as string[])
+        .map(p => nodeForPath(rootNode, path.join(parentNode.path, p)))
+        .filter(isTruthy) ?? []
+    : parentNode.children;
+
   return (
     <nav>
       {header && <h2>{header}</h2>}
       <ul>
-        {parentNode.children
+        {children
           /* NOTE: temp fix while we figure out the reason why some nodes have empty front matter */
           .filter(c => c.frontmatter.title)
           .map(n => (

src/utils.ts

@@ -1,6 +1,18 @@
 import type {Transaction} from '@sentry/browser';
 import qs from 'query-string';
 
+/**
+ * This function is used to filter out any elements that are not truthy and plays nice with TypeScript.
+ * @param x - The value to check for truthiness.
+ * @example
+ * ```typeScript
+ * let numbers: number[] = [1, undefined, 3, null, 5].filter(isTruthy);
+ * ```
+ */
+export const isTruthy = <T>(x?: T): x is Exclude<T, null | undefined> => {
+  return x !== null && x !== undefined;
+};
+
 export function sortBy<A>(arr: A[], comp: (v: A) => number): A[] {
   return arr.sort((a, b) => {
     const aComp = comp(a);