The Cadence Language Server implements the Language Server Protocol (LSP). It provides editors and IDEs that support LSP language features like auto complete, go to definition, documentation and type information on hover, etc.
Traditionally providing such features had to repeatedly implemented for each tool, as each tool provides different APIs for implementing the same feature. By implementing the LSP, the Cadence Language Server can be re-used in multiple development tools. For example, it is used by the Visual Studio Code extension (through the Flow CLI, which embeds the language server), and also in the Flow Playground (by compiling the language server to WebAssembly).
The main functionality of the language server, such as providing reporting diagnostics (e.g. errors), auto completion, etc. is implemented in the server package.
The Cadence language server optionally provides integration with the Flow network, such as signing and submitting transactions.
This code can be found in the integration package.
The Go code for the LSP types can be found in the protocol package.
The code is generated from the specification's TypeScript declarations using scripts.
The Cadence language server can be compiled to WebAssembly. It currently assumes to be used in a JavaScript environment.
GOARCH=wasm GOOS=js go build -o languageserver.wasm ./cmd/languageserverThe integration tests for the Cadence Language Server are written in TypeScript
and can be found in the test directory.