function browserInstalled()

in src/browser.js [198:229]

• 24 lines of code
• 4 McCabe index (conditional complexity)

function browserInstalled (browser) {
    // On Windows, the 'start' command searches the path then 'App Paths' in the registry.
    // We do the same here. Note that the start command uses the PATHEXT environment variable
    // for the list of extensions to use if no extension is provided. We simplify that to just '.EXE'
    // since that is what all the supported browsers use. Check path (simple but usually won't get a hit)

    const promise = new Promise((resolve, reject) => {
        if (which.sync(browser, { nothrow: true })) {
            return resolve();
        } else {
            const regQPre = 'reg QUERY "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\App Paths\\';
            const regQPost = '.EXE" /v ""';
            const regQuery = regQPre + browser.split(' ')[0] + regQPost;

            child_process.exec(regQuery, (err, stdout, stderr) => {
                if (err) {
                    // The registry key does not exist, which just means the app is not installed.
                    reject(err);
                } else {
                    const result = regItemPattern.exec(stdout);
                    if (fs.existsSync(trimRegPath(result[2]))) {
                        resolve();
                    } else {
                        // The default value is not a file that exists, which means the app is not installed.
                        reject(new Error(NOT_INSTALLED));
                    }
                }
            });
        }
    });
    return promise;
}