VS-Code command inputs using an (example) extension - visual-studio-code

Question

In the VSCode documentation for variable substitution, it says there is now a way of using an extension to generate a list of options. Specifically, it gives an example and then says "It is assumed that some extension provides an extension.mochaSupport.testPicker command...".
I accept there is help provided in how to get started with extensions of various kinds, but I was wondering if anyone had indeed already written something equivalent to extension.mochaSupport.testPicker?
I appreciate it's probably trivial for someone not starting from scratch, but the graphic simulation on the first page implies someone has indeed already written such an extension (to generate the graphic), so my question is "does anyone know of an extension that is documented anywhere that complements this example to select an input from a list?"

Answer 1

I was faced with the same issue, so I wrote a small example extension. You can find the sample code on https://github.com/GianUlli/vscode-custom-command-input-example.
The basic idea is to register a command that returns a string. Following the official VS Code guide, you start by registering the command when the extension is activated in extension.ts in the activate function:
let disposable = vscode.commands.registerCommand(
'vscode-custom-command-input-example.pickTestCase',
async () => {
return pickTestCase().catch(console.error);
}
);
context.subscriptions.push(disposable);
pickTestCase is the custom function that extracts all test cases from the workspace using a glob search.
export async function pickTestCase() {
let workingFolder = getWorkspaceFolder();
return new Promise<string[]>((resolve, reject) => {
glob('*.json', { cwd: workingFolder }, (err, files) => {
if (err) {
return reject(err);
}
resolve(files);
});
})
.then((files) => {
if (files.length > 0) {
return window.showQuickPick(files);
} else {
window.showErrorMessage('Could not find any test cases.');
return undefined;
}
})
.then((testCase) => {
return testCase;
});
}
Do not forget to register the command in package.json:
"contributes": {
"commands": [
{
"command": "vscode-custom-command-input-example.pickTestCase",
"title": "Pick a test case"
}
]
}
With those pieces, the user is now able to put ${command:vscode-custom-command-input-example.pickTestCase} in his task definitions (.vscode/tasks.json) and launch configurations (.vscode/launch.json), for example in a build task:
{
"label": "Echo example",
"command": "echo",
"type": "shell",
"args": ["${command:vscode-custom-command-input-example.pickTestCase}"],
"presentation": {
"reveal": "always"
},
"group": "build"
}