Greamonkey Scripts: detect npm package support TypeScript.

npm: package support types.user.js

// ==UserScript==
// @name npm: package support types
// @namespace info.efcl
// @match https://www.npmjs.com/package/*
// @grant GM_xmlhttpRequest
// ==/UserScript==

// License: MIT © azu
const NAME = "$Greasemonkey:package support types$";
const fetchPackage = (packageName) => {
    return new Promise((resolve, reject) => {
        // https://github.com/npm/registry/blob/master/docs/REGISTRY-API.md#getpackageversion
        // @scope/name => @scope%2Fname
        const path = packageName.replace(/\//g, "%2F");
        GM_xmlhttpRequest({
            method: "GET",
            url: `https://registry.npmjs.com/${path}`,
            onload: function(response) {
                try {
                    resolve(JSON.parse(response.responseText));
                } catch (error) {
                    reject(error);
                }
            },
            onerror: function(response) {
                reject(new Error(response.responseText));
            }
        });
    });
};

const insertToTop = (message) => {
    const top = document.querySelector("#top");
    if (!top) {
        throw new Error(NAME + " Not found #top");
    }
    const p = document.createElement("p");
    const span = document.createElement("span");
    span.setAttribute("style", "color:green");
    span.textContent = "TYPE: ";
    p.append(span);
    p.append(document.createTextNode(message));
    top.firstElementChild.insertAdjacentElement("beforebegin", p);
};

(async () => {
    const packagePattern = /https:\/\/www\.npmjs\.com\/package\/([^\/?#&]+)/;
    try {
        const match = location.href.match(packagePattern);
        if (!match) {
            throw new Error(NAME + "Does not match packageName");
        }
        const [all, packageName] = match;
        if (!packageName) {
            throw new Error(NAME + "Not found packageName");
        }
        const pkg = await fetchPackage(packageName).catch(error => {
            console.log(NAME, "does not `types` field");
        });
        if (typeof pkg["types"] === "string") {
            insertToTop("support `types` field in package.json");
            return;
        }
        if (typeof pkg["typings"] === "string") {
            insertToTop("support `typings` field in package.json");
            return;
        }
        const typesPkg = await fetchPackage(`@types/${packageName}`).catch(error => {
            console.log(NAME, "does not has @types package");
        });
        if (typeof typesPkg === "object") {
            insertToTop("support `@types` packages: " + `@types/${packageName}`);
            return;
        }
        throw new Error("Does not support types");
    } catch (error) {
        insertToTop(error.message);
    }
})();