Complete type safety across all JS/TS

.remarkrc.mjs

@@ -1,6 +1,8 @@
-import remarkPresetLintRecommended from 'remark-preset-lint-recommended';
+// @ts-check
+
 import remarkFrontmatter from 'remark-frontmatter';
 import remarkMdx from 'remark-mdx';
+import remarkPresetLintRecommended from 'remark-preset-lint-recommended';
 import remarkNoInlineCodeFences from './src/plugins/remark-no-inline-code-fences.mjs';
 import remarkNoHtmlLinks from './src/plugins/remark-no-html-links.mjs';
 import remarkLintNoDeadUrls from 'remark-lint-no-dead-urls';

astro.config.mjs

@@ -5,7 +5,7 @@ import remarkGlossary from './src/plugins/remark-glossary';
 import remarkCenter from './src/plugins/remark-center';
 import remarkFigure from './src/plugins/remark-figure';
 import remarkImageAttributes from './src/plugins/remark-image-attributes';
-import { remarkMdxGlobalImports } from './src/plugins/remark-mdx-global-imports.ts';
+import { remarkMdxGlobalImports } from './src/plugins/remark-mdx-global-imports';
 import remarkCodeRegion from './src/plugins/remark-code-region';
 
 export default defineConfig({

eslint.config.mjs

@@ -18,6 +18,7 @@ export default [
                 { argsIgnorePattern: '^_' },
             ],
             '@typescript-eslint/no-explicit-any': 'error',
+            'no-undef': 'off',
         },
     },
 
@@ -28,8 +29,5 @@ export default [
                 ImageMetadata: 'readonly',
             },
         },
-        rules: {
-            'no-undef': 'off',
-        },
     },
 ];

package.json

@@ -38,6 +38,7 @@
         "astro-eslint-parser": "^1.4.0",
         "eslint": "^10.5.0",
         "eslint-plugin-astro": "^1.7.0",
+        "mdast-util-mdx": "^3.0.0",
         "husky": "^9.1.7",
         "lint-staged": "^17.0.8",
         "mdast-util-mdx-jsx": "^3.2.0",

scripts/validate-regions.ts

@@ -22,20 +22,19 @@ function parseCodeRegionSources(content: string): Map<string, string> {
     const frontmatterMatch = content.match(FRONTMATTER_RE);
     if (!frontmatterMatch) return sources;
 
-    const lines = frontmatterMatch[1].split('\n');
+    const lines = frontmatterMatch[1]!.split('\n');
     const startIdx = lines.findIndex((line) =>
         CODE_REGION_SOURCES_KEY_RE.test(line),
     );
     if (startIdx === -1) return sources;
 
-    for (let i = startIdx + 1; i < lines.length; i++) {
-        const line = lines[i];
+    for (const line of lines.slice(startIdx + 1)) {
         // Stop once we hit a line that isn't indented (end of the map).
         if (!/^\s+\S/.test(line)) break;
 
         const m = line.match(CODE_REGION_SOURCE_ENTRY_RE);
         if (m) {
-            sources.set(m[1], m[2]);
+            sources.set(m[1]!, m[2]!);
         }
     }
 
@@ -89,7 +88,7 @@ function walkMdx(dir: string) {
                 if (!referencedRegions.has(filePath)) {
                     referencedRegions.set(filePath, new Set());
                 }
-                referencedRegions.get(filePath)!.add(regionName);
+                referencedRegions.get(filePath)!.add(regionName!);
             }
         }
     }
@@ -106,10 +105,11 @@ function validateSource(filePath: string) {
     const stack: { name: string; lineNum: number }[] = [];
     const rel = relative(EXAMPLES_DIR, filePath).replace(/\\/g, '/');
 
-    for (let i = 0; i < lines.length; i++) {
-        let m = lines[i].match(START_RE);
+    for (const [i, line] of lines.entries()) {
+        let m = line.match(START_RE);
         if (m) {
-            const name = m[1];
+            const name = m.at(1);
+            if (!name) continue;
             if (regions.has(name)) {
                 errors.push(`${rel}:${i + 1}: Duplicate region "${name}"`);
             }
@@ -118,15 +118,16 @@ function validateSource(filePath: string) {
             continue;
         }
 
-        m = lines[i].match(END_RE);
+        m = line.match(END_RE);
         if (m) {
             const name = m[1];
-            if (stack.length === 0) {
+            const top = stack.at(-1);
+            if (top === undefined) {
                 errors.push(
                     `${rel}:${i + 1}: Unmatched closing tag [/${name}] — no region opened`,
                 );
-            } else if (stack[stack.length - 1].name !== name) {
-                const expected = stack[stack.length - 1].name;
+            } else if (top.name !== name) {
+                const expected = top.name;
                 errors.push(
                     `${rel}:${i + 1}: Region mismatch — expected [/${expected}] but found [/${name}]`,
                 );
@@ -164,7 +165,7 @@ walkExamples(EXAMPLES_DIR);
 for (const [filePath, names] of referencedRegions) {
     const defs = definedRegions.get(filePath);
     for (const name of names) {
-        if (!defs || !defs.has(name)) {
+        if (!defs?.has(name)) {
             errors.push(
                 `${filePath}: Region "${name}" referenced in MDX but not defined in examples/${filePath}`,
             );
@@ -175,7 +176,7 @@ for (const [filePath, names] of referencedRegions) {
 for (const [filePath, names] of definedRegions) {
     const refs = referencedRegions.get(filePath);
     for (const [name, lineNum] of names) {
-        if (!refs || !refs.has(name)) {
+        if (!refs?.has(name)) {
             errors.push(
                 `${filePath}:${lineNum}: Orphaned region "${name}" — defined but never referenced in any .mdx file`,
             );

src/components/Slides.astro

@@ -152,7 +152,7 @@ function parseSequentialContent(content: string): ParsedSlide[] {
         const srcMatch = tagAttrs.match(/src=["']([^"']+)["']/);
         const rawSrc = srcMatch ? srcMatch[1] : '';
         const altMatch = tagAttrs.match(/alt=["']([^"']*?)["']/);
-        const alt = altMatch ? altMatch[1] : '';
+        const alt = altMatch?.[1] ?? '';
 
         if (!rawSrc) return;
 

src/config/sidebarConfig.ts

@@ -13,6 +13,12 @@ export type SidebarSection = {
     items: SidebarItem[];
 };
 
+export type Item = {
+    label: string;
+    href?: string;
+    items?: Item[];
+};
+
 // Define which URL paths belong to which sidebar section
 export const sidebarSections: Record<string, SidebarSection[]> = {
     // Home page - minimal sidebar or none
@@ -341,12 +347,7 @@ export function getSidebarForPath(pathname: string): SidebarSection[] {
         }
     }
 
-    if (bestMatch) {
-        return sidebarSections[bestMatch];
-    }
-
-    // Default to home (empty sidebar)
-    return sidebarSections['/'] || [];
+    return sidebarSections[bestMatch || '/'] ?? sidebarSections['/'] ?? [];
 }
 
 /**
@@ -395,12 +396,10 @@ export function getPrevNextLinks(pathname: string): {
     if (currentIndex === -1) {
         return { prev: null, next: null };
     }
-
+    const prev = allLinks.at(currentIndex - 1) ?? null;
+    const next = allLinks.at(currentIndex + 1) ?? null;
     return {
-        prev: currentIndex > 0 ? allLinks[currentIndex - 1] : null,
-        next:
-            currentIndex < allLinks.length - 1
-                ? allLinks[currentIndex + 1]
-                : null,
+        prev,
+        next,
     };
 }

src/plugins/remark-center.ts

@@ -1,33 +1,16 @@
 import { visit } from 'unist-util-visit';
 import type { Root } from 'mdast';
 
-interface ContainerDirective {
-    type: 'containerDirective';
-    name: string;
-    attributes?: Record<string, string>;
-    children: unknown[];
-    data?: {
-        hName?: string;
-        hProperties?: Record<string, unknown>;
-    };
-}
-
 export function remarkCenter() {
     return (tree: Root) => {
-        visit(
-            tree,
-            'containerDirective',
-            // eslint-disable-next-line @typescript-eslint/no-explicit-any
-            (node: any) => {
-                const dir = node as ContainerDirective;
-                if (dir.name !== 'center') return;
+        visit(tree, 'containerDirective', (node) => {
+            if (node.name !== 'center') return;
 
-                dir.data = dir.data || {};
-                dir.data.hName = 'div';
-                dir.data.hProperties = dir.data.hProperties || {};
-                dir.data.hProperties.class = 'centered-content';
-            },
-        );
+            node.data = node.data || {};
+            node.data.hName = 'div';
+            node.data.hProperties = node.data.hProperties || {};
+            node.data.hProperties.class = 'centered-content';
+        });
     };
 }
 

src/plugins/remark-code-region.ts

@@ -19,7 +19,7 @@ export default function remarkCodeRegion() {
             const meta: string = node.meta || '';
 
             const token = meta.match(/^(\S+)/);
-            if (!token) return;
+            if (!token?.[1]) return;
 
             const raw = token[1];
             const hashIdx = raw.indexOf('#');
@@ -107,6 +107,6 @@ function dedent(str: string): string {
                 Math.min(min, l.match(/^[ \t]*/)?.[0].length ?? Infinity),
             Infinity,
         );
-    if (indent === 0 || !isFinite(indent)) return str;
+    if (indent === 0 || !Number.isFinite(indent)) return str;
     return lines.map((l) => l.slice(indent)).join('\n');
 }