Solidity Language Server

A language server for the Solidity programming language, used in the Solidity by Nomic Foundation VS code extension and the @nomicfoundation/coc-solidity coc.nvim extension.

Built by the Nomic Foundation for the Ethereum community.

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Install

The language server can be installed via npm:

npm install @ignored/solidity-language-server -g

To run the server standalone:

nomicfoundation-solidity-language-server --stdio

coc.nvim

For coc the extension for this language server (found here) can be installed through the coc vim command:

:CocInstall @ignored/coc-solidity

neovim lsp

To run the language server directly through the neovim lsp (assuming neovim/nvim-lspconfig)

local lspconfig = require 'lspconfig'
local configs = require 'lspconfig.configs'

configs.solidity = {
  default_config = {
    cmd = {'nomicfoundation-solidity-language-server', '--stdio'},
    filetypes = { 'solidity' },
    root_dir = lspconfig.util.find_git_ancestor,
    single_file_support = true,
  },
}

lspconfig.solidity.setup {}

Features

Code Completions

The solidity language server autocompletes references to existing symbols (e.g. contract instances, globally available variables and built-in types like arrays) and import directives (i.e. it autocompletes the path to the imported file).

Direct imports (those not starting with ./ or ../) are completed based on suggestions from ./node_modules.

Relative imports pull their suggestions from the file system based on the current solidity file's location.

Natspec documentation completion is also supported

Navigation

Move through your codebase with semantic navigation commands:

Go to Definition

Navigates to the definition of an identifier.

Go to Type Definition

Navigates to the type of an identifier.

Go to References

Shows all references of the identifier under the cursor.

Renames

Rename the identifier under the cursor and all of its references:

Format document

Apply solidity formatting to the current document.

The formatting configuration can be overriden through a .prettierrc file, see Formatting Configuration.

Hover

Hovering the cursor over variables, function calls, errors and events will display a popup showing type and signature information:

Inline code validation (Diagnostics)

As code is edited, Solidity by Nomic Foundation runs the solc compiler over the changes and displays any warnings or errors it finds.

This feature is only available in solidity files that are part of a Hardhat project, as Hardhat is used for import resolution, see Hardhat Projects for details.

Code Actions

Code actions, or quickfixes are refactorings suggested to resolve a solc warning or error.

A line with a warning/error that has a code action, will appear with small light bulb against it; clicking the light bulb will provide the option to trigger the code action.

Implement missing functions on interface

A contract that implements an interface, but is missing functions specified in the interface, will get a solidity(3656) error.

The matching code action Add missing functions from interface will determine which functions need to be implemented to satisfy the interface and add them as stubs to the body of the contract.

Constrain mutability

A function without a mutability keyword but which does not update contract state will show a solidity(2018) warning, with solc suggesting adding either the view or pure keyword depending on whether the function reads from state.

The matching code action Add view/pure modifier to function declaration resolves the warning by adding the keyword to the function signature.

Adding virtual/override on inherited function signature

A function in an inheriting contract, that has the same name and parameters as a function in the base contract, causes solidity(4334) in the base contract function if it does not have the virtual keyword and solidity(9456) in the inheriting contract function if does not have the override keyword.

The Add virtual specifier to function definition and Add override specifier to function definition code actions appear against functions with these errors.

Adding public/private to function signature

A function without an accessibility keyword will cause the solidity(4937) error.

Two code actions will appear against a function with this error: Add public visibility to declaration and Add private visibility to declaration.

Adding license identifier and pragma solidity version

When no license is specified on a contract, the solidity(1878) warning is raised by the compiler. Similarly, when no compiler version is specified with a pragma solidity statement, the compiler shows the solidity(3420) warning. There are code actions available for quick fixes.

Specifying data location for variables

Some types require you to specify a data location (memory, storage, calldata), depending on where they are defined. The available code actions allow the user to add, change or remove data locations depending on the error being raised.

Fix addresses checksum

The solidity compiler requires explicit addresses to be in the correct checksummed format. This quickfix transforms any address to the expected format.

Hardhat console auto-import

Hardhat's console.sol can be imported with this quickfix. Please note that this only available on hardhat projects.

Hardhat Projects

Solidity by Nomic Foundation provides enhanced functionality for Solidity files within a Hardhat project, including inline validation and quick fixes.

To take advantage of these features, use the File menu to Open Folder, and select the folder containing the hardhat.config.{js,ts} file.

Inline validation (the display of compiler errors and warnings against the code) is based on your Hardhat configuration file. The version of the solc solidity compiler used for validation is set within this file, see the Hardhat documentation for more details.

Monorepo Support

Solidity by Nomic Foundation will detect Hardhat projects (folders containing a hardhat.config.{js,ts} file) within a monorepo, when the root of the monorepo is opened as a workspace folder.

The Hardhat config file that is used when validating a Solidity file is shown in the Solidity section on the Status Bar:

Contributing

Contributions are always welcome! Feel free to open any issue or send a pull request.

Go to CONTRIBUTING.md to learn about how to set up a development environment.

Feedback, help and news

Hardhat Support Discord server: for questions and feedback.

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