get all available gutenberg block info for your site with javascript

list_blocks.js

/* Navigate to a wordpress edit page for any post and run one of the code sections below in a javascript console to get the names/info for all blocks available to gutenberg on your site. */

/* log all block info to console */
console.log(wp.data.select( "core/blocks" ).getBlockTypes());

/* log all block names to console */
wp.data.select( "core/blocks" ).getBlockTypes().forEach(function(element) {
  console.log(element['name']);
});

/* print all block names to a new window */
var win = window.open("", "Title", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=780,height=200,top="+(screen.height-400)+",left="+(screen.width-840));
var tmpContent = 'Blocks<br><hr><br>';
wp.data.select( "core/blocks" ).getBlockTypes().forEach(function(element) {
  tmpContent = tmpContent + element['name'] + "<br>";
});
win.document.body.innerHTML = tmpContent;

/* same thing but formatted for a php array with commented descriptions */
var win = window.open("", "Title", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=780,height=200,top="+(screen.height-400)+",left="+(screen.width-840));
var tmpContent = 'Block List<br><hr><br>array(<br>';
wp.data.select( "core/blocks" ).getBlockTypes().forEach(function(element) {
  tmpContent = tmpContent + "'" + element['name'] + "',  //"+element['description']+"<br>";
});
tmpContent = tmpContent + ');';
win.document.body.innerHTML = tmpContent;