background.js

chrome.contextMenus.onClicked.addListener(contextClick)

async function getCurrentTab() {
    let queryOptions = {active: true, currentWindow: true};
    let [tab] = await chrome.tabs.query(queryOptions);
    return tab;
}

function injectedFunction_egrave(text) {
    let input = document.createElement('textarea');
    document.body.appendChild(input);
    input.value = text;
    input.focus();
    input.select();
    document.execCommand("copy");
    input.remove();
}

function copyToClipboard(text) {
    console.log(text);
    getCurrentTab().then(function (tab) {
        chrome.scripting.executeScript({
            target: {tabId: tab.id},
            args: [text],
            function: injectedFunction_egrave
        });
    });
}

chrome.runtime.onInstalled.addListener(function () {
    chrome.contextMenus.create({
        "id": "create_bitly_form_selection",
        "title": "Shorten selection and copy to clipboard",
        "contexts": ["selection"],
    });

    chrome.contextMenus.create({
        "id": "create_bitly_from_link",
        "title": "Shorten link and copy to clipboard",
        "contexts": ["link"],
    });
});

function contextClick(info) {
    const {menuItemId} = info

    if (menuItemId === 'create_bitly_form_selection') {
        shorten(info['selectionText'])
    }

    if (menuItemId === 'create_bitly_from_link') {
        shorten(info['linkUrl'])
    }
}

function shorten(text) {
    if (text == "")
        return;

    copyToClipboard('Shortening, please wait a while...');

    chrome.storage.sync.get(['token'], function (result) {
        const token = result.token;

        if (token == null) {
            copyToClipboard('Please set your token in the options page');
        }

        fetch('https://api-ssl.bitly.com/v4/shorten', {
            method: 'POST',
            headers: {
                'Authorization': 'Bearer ' + token,
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({"long_url": text, "domain": "bit.ly"})
        }).then((data) => {
            data.json().then((json) => {
                copyToClipboard(json.link)
            })
        })

    });
}