Skip to content
tflw

8. The editor

Everything so far ran from a terminal. Day to day, a suite is written in an editor, and tflw's VS Code extension gives you the same checks tflw check runs, underlined as you type, plus your tests in VS Code's Test Explorer with a run button beside each.

Install the extension

Section titled “Install the extension”

Until 1.0 the extension is not on the Marketplace, so it is packaged from the clone chapter 1 made. npm run package writes one .vsix file, which VS Code installs as it would a download. It runs inside packages/vscode/, so $PWD in the output name puts the file where you are. The last line opens the project:

Terminal window
cd ../tflw
npm run package -w tflw-vscode -- -o "$PWD/tflw.vsix"
code --install-extension tflw.vsix
cd ../coffee-shelf
code .

This is a declared exception to every command is run: the check has no clone, and no VS Code window to install into.

The extension runs your project's own tflw, the one in node_modules, so what it underlines is what tflw check reports and what CI runs. Open tests/my-order.tflw from chapter 4 and change equals to equal: the line is underlined before you save, with the same message tflw check prints, and Quick Fix offers the spelling it meant.

The Test Explorer

Section titled “The Test Explorer”

The beaker icon lists every .tflw file and the tests in it. Run one test, one file or all of them; each turns green or red as tflw reports it, and a failure opens at the step that failed with tflw's own message. ▶ Run test above each test line does the same from the file. The repeated steps refactor apply extracted in chapter 4 are offered here too, as a code action on the lines.

Other editors

Section titled “Other editors”

The extension is a thin client for tflw lsp, a language server, which any editor that speaks the Language Server Protocol can run: Neovim, Helix, Zed, Sublime Text, Emacs. Point the editor's language-server setting for .tflw files at this command, run from the project's directory:

Terminal window
npx tflw lsp

You do not run it yourself: it talks to the editor over its input and output and waits for one to connect. It is a declared exception for that reason.

You now have

Section titled “You now have”

The project open in an editor that checks as you type and runs tests from the Test Explorer. Nothing in the project changed.

Next, or instead

Section titled “Next, or instead”