User script that adds a hotkey to open the docs.rs link for the currently viewed crate on crates.io.

docs_rs_hotkey_for_crates_io.user.js

// ==UserScript==
// @name        docs.rs hotkey for crates.io
// @namespace   Violentmonkey Scripts
// @match       https://crates.io/*
// @grant       none
// @version     1.1
// @author      @jix_
// @description Press d to open the docs.rs link for the currently viewed crate on crates.io.
// ==/UserScript==

const openLink = function (heading) {
  for (headingTag of document.querySelectorAll('section[aria-label="Crate metadata"] h3')) {
    if (headingTag.innerText !== heading) 
      continue;
    const link = headingTag.parentNode.querySelector('a');
    if (link === null) {
      console.log(`Could not find link under heading ${heading}`);
    } else {
      window.open(link.href, '_blank');
    }
    return;
  }
  console.log(`Could not find link with heading ${heading}`);
};

const openTab = function (index) {
  let tabs = document.querySelectorAll('main nav li a');
  tabs[index].click();
}


document.body.addEventListener('keydown', function (event) {
  if (event.target !== document.body || event.ctrlKey || event.altKey || event.metaKey)
    return;
  if (event.key === 'd') {
    openLink('Documentation');
  } else if (event.key === 'r') {
    openLink('Repository');
  } else if (event.key === 'h') {
    openLink('Homepage');
  } else if (event.key >= '1' && event.key <= '9') {
    openTab(Number(event.key) - 1);
  }
});