Add typescript guideline and typescript-specific eslint plugins and fix issues (#31521)

1. Add some general guidelines how to write our typescript code
2. Add `@typescript-eslint/eslint-plugin`, general typescript rules
3. Add `eslint-plugin-deprecation` to detect deprecated code
4. Fix all new lint issues that came up

1 files changed, 2 insertions, 2 deletions

diff --git a/web_src/js/features/repo-findfile.js b/web_src/js/features/repo-findfile.js
index 945eeeceff..828acfa65c 100644
--- a/web_src/js/features/repo-findfile.js
+++ b/web_src/js/features/repo-findfile.js
@@ -55,8 +55,8 @@ export function filterRepoFilesWeighted(files, filter) {
     const filterLower = filter.toLowerCase();
     // TODO: for large repo, this loop could be slow, maybe there could be one more limit:
     // ... && filterResult.length < threshold * 20,  wait for more feedbacks
-    for (let i = 0; i < files.length; i++) {
-      const res = strSubMatch(files[i], filterLower);
+    for (const file of files) {
+      const res = strSubMatch(file, filterLower);
       if (res.length > 1) { // length==1 means unmatched, >1 means having matched sub strings
         filterResult.push({matchResult: res, matchWeight: calcMatchedWeight(res)});
       }