.use(() => unistUtilTrace.diff()) // first call: save tree
//...
.use(() => unistUtilTrace.diff()) // second call: show diff

const { unistUtilTrace } = require("unist-util-trace")
const traceDiffSettings = {
  reporter: ["unist-diff"]
}

module.exports = {
  plugins: [
    ["remark-frontmatter", "yaml"],
    [
      "remark-retext",
      unified()
        .use(require("retext-english"))
        .use(require("retext-syntax-urls"))
        .use(() => unistUtilTrace.diff(traceDiffSettings))  // first to set tracepoint
        .use(require("retext-syntax-mentions"), { style: /^@[\w-]{1,40}$/ })
        .use(() => unistUtilTrace.diff(traceDiffSettings)) // second to see diffs from mentions
        .use(require("retext-emoji"))
        .use(() => unistUtilTrace.diff(traceDiffSettings)) // third to see diffs in retext-emoji

const traceDiffSettings = {
  reporter: [ "unist-diff", 
              "diff-json", 
              "diff-inspect-full", 
              "diff-inspect-plain", 
              "json-diff-patch"
            ]
}