Can confirm, you can do some good vibe coding with JavaScript (or TypeScript) and Claude Code.
I once vibe coded a test suite for a complex OAuth token expiry issue while working on someone else's TypeScript code.
Also, I had created a custom Node.js/JavaScript BaaS platform with custom Web Components and wanted to build apps with it, I gave it the documentation as attachment and surprisingly, it was able to modify an existing app to add entire new features. This app had multiple pages and Claude just knew where to make the changes. I was building a kind of marketplace app. One time it implemented the review/rating feature in the wrong place and I told it "This rating feature is meant for buyers to review sellers, not for sellers to review buyers" and it fixed it exactly right.
I think my second experience (plain JavaScript) was much more impressive and was essentially frictionless. I can't remember it making a single major mistake. I think only once it forgot to add the listener to handle the click event to highlight when a star icon was clicked but it fixed it perfectly when I mentioned this. With TypeScript, it sometimes got confused; I had to help it a lot more because I was trying to mock some functions; the fact that the TypeScript source code is separate from the build code created some confusion and it was struggling to grep the codebase at times. Though I guess the code was also more complicated and spread out over more files. My JavaScript web components are intended to be low-code so it's much more succinct.
Also, I had created a custom Node.js/JavaScript BaaS platform with custom Web Components and wanted to build apps with it, I gave it the documentation as attachment and surprisingly, it was able to modify an existing app to add entire new features. This app had multiple pages and Claude just knew where to make the changes. I was building a kind of marketplace app. One time it implemented the review/rating feature in the wrong place and I told it "This rating feature is meant for buyers to review sellers, not for sellers to review buyers" and it fixed it exactly right.
I think my second experience (plain JavaScript) was much more impressive and was essentially frictionless. I can't remember it making a single major mistake. I think only once it forgot to add the listener to handle the click event to highlight when a star icon was clicked but it fixed it perfectly when I mentioned this. With TypeScript, it sometimes got confused; I had to help it a lot more because I was trying to mock some functions; the fact that the TypeScript source code is separate from the build code created some confusion and it was struggling to grep the codebase at times. Though I guess the code was also more complicated and spread out over more files. My JavaScript web components are intended to be low-code so it's much more succinct.