JavaScript in VSCode: language, tool, and analysis model

December 24, 2025

In VSCode, JavaScript is analyzed not as an independent language but as a projection of the TypeScript type model served by tsserver. This sets the boundaries of what the IDE can see in code and explains why some constructs are analyzed predictably while others remain opaque.

In the publication I examine the role of jsconfig.json, the architecture of the Language Server Protocol, and the place of JSDoc in a TypeScript-oriented analysis model. I also show why dynamic dependencies and late binding stay outside the TypeScript model used by VSCode.

The full text is available in the library material.