Hardhat for Visual Studio Code
This extension adds language support for Solidity to Visual Studio Code, and provides editor integration for Hardhat projects. Integrations for other tools are coming in the near future. It supports:
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Table of Contents
Installation
Hardhat for Visual Studio Code can be installed by using the Visual Studio Code Marketplace.
Some features (e.g. inline validation, quick fixes) are still experimental and are only enabled within a Hardhat project, this is a limitation that will be lifted with future releases.
Features
Code Completions
Hardhat for Visual Studio Code 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.
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:
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, Hardhat for Visual Studio Code 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.
Commands
Compile project
When working on a hardhat project, the command Hardhat: Compile project is available on the command palette. This will trigger a hardhat compile run.
Clean artifacts
When working on a hardhat project, the command Hardhat: Clear cache and artifacts is present on the command palette. This will trigger a hardhat clean run.
Flatten contract
When working on a solidity file inside a hardhat project, the command Hardhat: Flatten this file and its dependencies is present on the command palette and the context menu. This will trigger a hardhat flatten $FILE run, and will output the result in a new file tab.
Task provider
The extension is registered as a task provider for hardhat projects, in which the build task is provided , running hardhat compile, and the test task, which runs hardhat test.
Setup
This extension should work without any configuration. If formatting functionality isn't working, or you have previously configured another Solidity formatter, please see the formatting section.
Hardhat Projects
Hardhat for Visual Studio Code 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
Hardhat for Visual Studio Code 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:
Hardhat for Visual Studio Code provides formatting support for .sol files, by leveraging prettier-plugin-solidity.
Note: if you currently have other solidity extensions installed, or have had previously, they may be set as your default formatter for solidity files.
To set Hardhat for Visual Studio Code as your default formatter for solidity files:
- Within a Solidity file run the Format Document With command, either through the command palette, or by right clicking and selecting through the context menu:
- Select
Configure Default Formatter...
- Select
Solidity + Hardhat as the default formatter for solidity files
The default formatting rules that will be applied are taken from prettier-plugin-solidity, with the exception that explicitTypes are preserved (rather than forced).
To override the settings, add a prettierrc configuration file at the root of your project. Add a *.sol file override to the prettier configuration file and change from the defaults shown:
// .prettierrc.json
{
"overrides": [
{
"files": "*.sol",
"options": {
"printWidth": 80,
"tabWidth": 4,
"useTabs": false,
"singleQuote": false,
"bracketSpacing": false,
"explicitTypes": "preserve"
}
}
]
}
Feedback, help and news
Hardhat Support Discord server: for questions and feedback.
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