markdown-example.js

var unified = require("unified");
var remarkParse = require("remark-parse");
var remarkStringify = require("remark-stringify");
var { matches } = require("unist-util-select");
var remove = require("unist-util-remove");

var markdown = `
# Test

# No Really

## Test

Foo
`;

function plugin(options) {
  return function transformer(tree, file) {
    remove(tree, function(node) {
      return matches(`heading[depth=1]`, node);
    });
  };
}

unified()
  .use(remarkParse)
  .use(plugin)
  .use(remarkStringify)
  .process(markdown)
  .then(file => console.log(file.contents));

/*
## Test

Foo
*/