JavaScript file for importing GitHub labels from a JSON object.

github-labels-import.js

/**
 * 1. Update the labels JSON object.
 * 2. Open web browsers
 * 3. Navigate to desired GitHub repository.
 * 4. Navigate to Issues tab.
 * 5. Navigate to Labels link.
 * 6. Open web browswer Developer Tools
 * 7. Navigate to the Console window.
 * 8. Copy and Paste the below code snippets into the Console window.
  */

const labels = [
    {
        "name": "bug",
        "description": "Something isn't working",
        "color": "ff7a86"
    },
    {
        "name": "enhancement",
        "description": "Internal improvements",
        "color": "a3c3ff"
    },
    {
        "name": "feature",
        "description": "New feature or request",
        "color": "58de8f"
    },
    {
        "name": "question",
        "description": "Further information is requested",
        "color": "f470ed"
    }
];

// Function to update an existing label
function updateLabel(label) {
    let flag = false;
    [].slice.call(document.querySelectorAll(".labels-list-item"))
        .forEach(function(element) {
            if (element.querySelector(".label-link").textContent.trim() === label.name) {
                flag = true;
                element.querySelector(".js-edit-label").click();
                element.querySelector(".js-new-label-name-input").value = label.name;
                element.querySelector(".js-new-label-description-input").value = label.description;
                element.querySelector(".js-new-label-color-input").value = "#" + label.color;
                element.querySelector(".js-edit-label-cancel ~ .btn-primary").click();
            }
        });
    return flag;
}

// Function to add a new label
function addNewLabel(label) {
    document.querySelector(".js-new-label-name-input").value = label.name;
    document.querySelector(".js-new-label-description-input").value =
        label.description;
    document.querySelector(".js-new-label-color-input").value =
        "#" + label.color;
    document.querySelector(
        ".js-details-target ~ .btn-primary"
    ).disabled = false;
    document.querySelector(".js-details-target ~ .btn-primary").click();
}

// Function to add a new label
function addLabel(label) {
    if (!updateLabel(label)) {
        addNewLabel(label);
    }
}

// Importing labels from JSON.
// This one is not available natively in IE, but there are polyfills available.
Promise.resolve().then(function(){
    labels.forEach(function(label) {
        addLabel(label);
        });
});

Extract existing labels:

let labels = [];
document.querySelectorAll('.js-label-list > div').forEach(labelDiv => {
    let name = labelDiv.querySelector('a').getAttribute('data-name');
    let descriptionElement = labelDiv.querySelector('.js-hide-on-label-edit span');
    let description = descriptionElement ? descriptionElement.innerText : '';
    let colorId = labelDiv.querySelector('span.IssueLabel').getAttribute('id');
    let color = colorId.slice(6); // Removes the "label-" prefix

    labels.push({ name, description, color });
});

console.log(JSON.stringify(labels, null, 4));