Setting up R in Visual Studio Code

This post will show you how to set up Visual Studio Code as an integrated development environment for the statistical language R. This will include some useful features such as:

• plots that appear within a VS Code panel
• a language server with autocomplete
• syntax highlighting of R code in console and scripts
• interactive window development

Of course, RStudio has all of these features for R too. However, Visual Studio Code does a lot more than just R, and has tons of cutting edge integrated development environment features that we’d like to make use of.

The prerequisites are:

1. An installation of the R language
2. An installation of Python
3. Visual Studio Code
4. The R extension for Visual Studio Code

Steps:

1. Install the Python package radian, which provides multiline editing and rich syntax highlighting. It sells itself as “A 21 century R console”. The installation can be achieved by running conda install -c conda-forge radian on the command line, if you manage your Python environments with conda, or pip install -U radian if you use pip.
2. Start up R (wherever) and run install.packages("languageserver") to install a language server.
3. Also install.packages("httpgd") to install the plot viewer.
4. Hit Ctrl (command on mac) + , in Visual Studio Code to open up the settings. Then make the following changes: enable R Bracketed Paste, R Session Watcher, and R: Always Use ActiveTerminal.
5. Now we want to make plots show up automatically within Visual Studio Code. If you don’t have an R profile on your computer already, create it with touch ~/.Rprofile. You can check if you have it already using ls -a ~.
6. Use code ~/.Rprofile to open the Rprofile file. Add the following code to it:

if (interactive() && Sys.getenv("RSTUDIO") == "") {
  Sys.setenv(TERM_PROGRAM = "vscode")
  if ("httpgd" %in% .packages(all.available = TRUE)) {
    options(vsc.plot = FALSE)
    options(device = function(...) {
      httpgd::hgd(silent = TRUE)
      .vsc.browser(httpgd::hgd_url(history = FALSE), viewer = "Beside")
    })
  }
  source(file.path(Sys.getenv(if (.Platform$OS.type == "windows") "USERPROFILE" else "HOME"), ".vscode-R", "init.R"))
}

7. In the terminal window of VS Code, type radian to bring up the R console.
8. Create an R script. Why not try writing hist(trees$Height, breaks = 10, col = "orange") in it? Then use Ctrl (command on mac) + ⏎ to send the line of code to the console. You should see your plot appear!

Tips:

• You can find the workspace viewer under the R tab on the left-hand side of VS Code along with the Help Pages.
• To bring up the variable explorer, use View(data) where data is an object containing data.
• Interactive plotly charts work, as does a webviewer (eg for Shiny apps; try shiny::runExample("01_hello"))
• Help pages can be revealed via ?symbol in the console

You can find more information on the R extension for VS Code here.