Go for Visual Studio Code

Important Note: If you have recently upgraded to Go 1.8 or Go 1.9, you may need to run gocode close in your terminal and rebuild gocode to ensure Go completion lists continue to work correctly. See microsoft#441.

Read the Release Notes to know what has changed over the last few versions of this extension

This extension adds rich language support for the Go language to VS Code, including:

• Completion Lists (using gocode)
• Signature Help (using gogetdoc or godef+godoc)
• Snippets
• Quick Info (using gogetdoc or godef+godoc)
• Goto Definition (using gogetdoc or godef+godoc)
• Find References (using guru)
• References CodeLens
• File outline (using go-outline)
• Workspace symbol search (using go-symbols)
• Rename (using gorename. Note: For Undo after rename to work in Windows you need to have diff tool in your path)
• Build-on-save (using go build and go test)
• Lint-on-save (using golint or gometalinter)
• Format (using goreturns or goimports or gofmt)
• Generate unit tests skeleton (using gotests)
• Add Imports (using gopkgs)
• Add/Remove Tags on struct fields (using gomodifytags)
• Semantic/Syntactic error reporting as you type (using gotype-live)
• Run Tests under the cursor, in current file, in current package, in the whole workspace (using go test)
• Generate method stubs for interfaces (using impl)
• [partially implemented] Debugging (using delve)

IDE Features

Using

First, you will need to install Visual Studio Code. Then, in the command palette (cmd-shift-p) select Install Extension and choose Go.

In a terminal window with the GOPATH environment variable set to the GOPATH you want to work on, launch code. Open your GOPATH folder or any subfolder you want to work on, then open a .go file to start editing. You should see Analysis Tools Missing in the bottom right, clicking this will offer to install all of the Go tooling needed for the extension to support its full feature set. See the Tools section below for more details.

Note 1: Read GOPATH in the VS Code Go extension to learn about the different ways you can get the extension to set GOPATH.

Note 2: Users may want to consider turning Auto Save on in Visual Studio Code ("files.autoSave": "afterDelay") when using this extension. Many of the Go tools work only on saved files, and error reporting will be more interactive with Auto Save turned on. If you do turn Auto Save on, you may also want to turn format-on-save off ("go.formatOnSave": false), so that it is not triggered while typing.

Note 3: This extension uses gocode to provide completion lists as you type. To provide fresh results, including against not-yet-built dependencies, the extension uses gocode's autobuild=true setting. If you experience any performance issues with autocomplete, you should try setting "go.gocodeAutoBuild": false in your VS Code settings.

Customizing the Go extension features

The Go extension is ready to use on the get go. If you want to customize the features, you can edit the settings in your User or Workspace settings. Read Settings for Visual Studio Code Go extension for the full list of options and their descriptions.

Go Language Server (Experimental)

Set go.useLanguageServer to true to use the Go language server from Sourcegraph for features like Hover, Definition, Find All References, Signature Help, Go to Symbol in File and Workspace.

• This is an experimental feature and is not available in Windows yet.
• If set to true, you will be prompted to install the Go language server. Once installed, you will have to reload VS Code window. The language server will then be run by the Go extension in the background to provide services needed for the above mentioned features.
• Everytime you change the value of the setting go.useLanguageServer, you need to reload the VS Code window for it to take effect.
• To collect traces, set "go.languageServerFlags": ["-trace"]
• To collect errors from language server in a logfile, set "go.languageServerFlags": ["-trace", "-logfile", "path to a text file that exists" ]

Linter

A linter is a tool giving coding style feedback and suggestions. By default this extension uses the official golint as a linter.

You can change the default linter and use the more advanced Go Meta Linter by setting go.lintTool to "gometalinter" in your settings.

Go meta linter uses a collection of various linters which will be installed for you by the extension.

Some of the very useful linter tools:

• errcheck checks for unchecked errors in your code.
• varcheck finds unused global variables and constants.
• deadcode finds unused code.

If you want to run only specific linters (some linters are slow), you can modify your configuration to specify them:

  "go.lintFlags": ["--disable-all", "--enable=errcheck"],

Alternatively, you can use megacheck which may have significantly better performance than gometalinter, while only supporting a subset of the tools.

Finally, the result of those linters will show right in the code (locations with suggestions will be underlined), as well as in the output pane.

Commands

In addition to integrated editing features, the extension also provides several commands in the Command Palette for working with Go files:

• Go: Add Import to add an import from the list of packages in your Go context
• Go: Current GOPATH to see your currently configured GOPATH
• Go: Test at cursor to run a test at the current cursor position in the active document
• Go: Test Package to run all tests in the package containing the active document
• Go: Test File to run all tests in the current active document
• Go: Test Previous to run the previously run test command
• Go: Test All Packages in Workspace to run all tests in the current workspace
• Go: Generates unit tests for package Generates unit tests for the current package
• Go: Generates unit tests for file Generates unit tests for the current file
• Go: Generates unit tests for function Generates unit tests for the selected function in the current file
• Go: Install Tools Installs/updates all the Go tools that the extension depends on
• Go: Add Tags Adds configured tags to selected struct fields.
• Go: Remove Tags Removes configured tags from selected struct fields.
• Go: Generate Interface Stubs Generates method stubs for given interface

You can access all of the above commands from the command pallet (Cmd+Shift+P or Ctrl+Shift+P).

Few of these are available in the editor context menu as an experimental feature as well. To control which of these commands show up in the editor context menu, update the setting go.editortorContextMenuCommands

Optional: Debugging

To use the debugger, you must currently manually install delve. See the Installation Instructions for full details. On OS X it requires creating a self-signed cert to sign the dlv binary.

For more read Debugging Go Code Using VS Code

Remote Debugging

To remote debug using VS Code, read Remote Debugging

Building and Debugging the Extension

You can set up a development environment for debugging the extension during extension development. Read more at Building, Debugging and Sideloading the extension in Visual Studio Code

Tools this extension depends on

This extension uses a host of Go tools to provide the various rich features. These tools are installed in your GOPATH by default. If you wish to have the extension use a separate GOPATH for its tools, provide the desired location in the setting go.toolsGopath. Read more about this and the tools at Go tools that the Go extension depends on

License

MIT