refactor: enable a few TS flags (#6852)

* refactor: enable a few TS flags

* refactor

* revert to working version

* fix

* better

* change

packages/docusaurus-utils/src/constants.ts

@@ -6,11 +6,11 @@
  */
 
 export const NODE_MAJOR_VERSION = parseInt(
-  process.versions.node.split('.')[0],
+  process.versions.node.split('.')[0]!,
   10,
 );
 export const NODE_MINOR_VERSION = parseInt(
-  process.versions.node.split('.')[1],
+  process.versions.node.split('.')[1]!,
   10,
 );
 

packages/docusaurus-utils/src/markdownLinks.ts

@@ -48,12 +48,13 @@ export function replaceMarkdownLinks<T extends ContentPaths>({
   let lastCodeFence = '';
   const lines = fileString.split('\n').map((line) => {
     if (line.trim().startsWith('```')) {
+      const codeFence = line.trim().match(/^`+/)![0]!;
       if (!fencedBlock) {
         fencedBlock = true;
-        [lastCodeFence] = line.trim().match(/^`+/)!;
+        lastCodeFence = codeFence;
         // If we are in a ````-fenced block, all ``` would be plain text instead
         // of fences
-      } else if (line.trim().match(/^`+/)![0].length >= lastCodeFence.length) {
+      } else if (codeFence.length >= lastCodeFence.length) {
         fencedBlock = false;
       }
     }
@@ -71,7 +72,7 @@ export function replaceMarkdownLinks<T extends ContentPaths>({
     let mdMatch = mdRegex.exec(modifiedLine);
     while (mdMatch !== null) {
       // Replace it to correct html link.
-      const mdLink = mdMatch.groups!.filename;
+      const mdLink = mdMatch.groups!.filename!;
 
       const sourcesToTry = [
         path.resolve(path.dirname(filePath), decodeURIComponent(mdLink)),

packages/docusaurus-utils/src/markdownParser.ts

@@ -18,8 +18,8 @@ export function parseMarkdownHeadingId(heading: string): {
   const matches = customHeadingIdRegex.exec(heading);
   if (matches) {
     return {
-      text: matches.groups!.text,
-      id: matches.groups!.id,
+      text: matches.groups!.text!,
+      id: matches.groups!.id!,
     };
   }
   return {text: heading, id: undefined};
@@ -51,14 +51,13 @@ export function createExcerpt(fileString: string): string | undefined {
 
     // Skip code block line.
     if (fileLine.trim().startsWith('```')) {
+      const codeFence = fileLine.trim().match(/^`+/)![0]!;
       if (!inCode) {
         inCode = true;
-        [lastCodeFence] = fileLine.trim().match(/^`+/)!;
+        lastCodeFence = codeFence;
         // If we are in a ````-fenced block, all ``` would be plain text instead
         // of fences
-      } else if (
-        fileLine.trim().match(/^`+/)![0].length >= lastCodeFence.length
-      ) {
+      } else if (codeFence.length >= lastCodeFence.length) {
         inCode = false;
       }
       continue;

packages/docusaurus-utils/src/tags.ts

@@ -80,13 +80,13 @@ export function groupTaggedItems<Item>(
     // TODO: it's not really clear what should be the behavior if 2 items have
     // the same tag but the permalink is different for each
     // For now, the first tag found wins
-    result[tag.permalink] = result[tag.permalink] ?? {
+    result[tag.permalink] ??= {
       tag,
       items: [],
     };
 
     // Add item to group
-    result[tag.permalink].items.push(item);
+    result[tag.permalink]!.items.push(item);
   }
 
   items.forEach((item) => {

packages/docusaurus-utils/src/urlUtils.ts

@@ -15,10 +15,17 @@ export function normalizeUrl(rawUrls: string[]): string {
   let hasStartingSlash = false;
   let hasEndingSlash = false;
 
+  const isNonEmptyArray = (arr: string[]): arr is [string, ...string[]] =>
+    arr.length > 0;
+
+  if (!isNonEmptyArray(urls)) {
+    return '';
+  }
+
   // If the first part is a plain protocol, we combine it with the next part.
   if (urls[0].match(/^[^/:]+:\/*$/) && urls.length > 1) {
-    const first = urls.shift();
-    if (first!.startsWith('file:') && urls[0].startsWith('/')) {
+    const first = urls.shift()!;
+    if (first.startsWith('file:') && urls[0].startsWith('/')) {
       // Force a double slash here, else we lose the information that the next
       // segment is an absolute path
       urls[0] = `${first}//${urls[0]}`;