gatsby-remark-dictionary/dev/remark-dictionary/plugin.js

Create a dictionary of word and phrases to be converted to highlighted values and links. define once and all phrases will be converted during build time.

const visit = require("unist-util-visit");
const toString = require("mdast-util-to-string")
const dictionary = require('./markdown-dictionary');

module.exports = () => (tree, file) => {
  const trie = getTrie(dictionary);
  visit(tree, "paragraph", (node) => {
    addDictionaryDefinitions(node, trie);
  });

  return tree;
}

const getTrie = (dictionary) => {
  const trie = {};

  dictionary.forEach(definition => {
      definition.matchers.forEach(matcher => {
          let trieMatcherNode = trie;
          const matcherWords = matcher.split(' ');
          matcherWords.forEach(word => {
              trieMatcherNode[word] = trieMatcherNode[word] || {};
              trieMatcherNode = trieMatcherNode[word];
          });

          trieMatcherNode.definition = definition;
      });
  });

  return trie;
}

const addDictionaryDefinitions = (node, trie) => {
    // Grab the innerText of the paragraph node
    let originalText = text = toString(node);
    const textSplittedToWords = text.split(' ');

    let currPlaceInTrie = trie, streakTextIndex = null, currTextIndex = 0;
    for (let i = 0; i < textSplittedToWords.length; i++) {
        const currWord = textSplittedToWords[i];

        const nextPlaceInTrie = currPlaceInTrie[currWord];
        if (!nextPlaceInTrie) {
            streakTextIndex = null;
            currPlaceInTrie = trie;
        } else if (!nextPlaceInTrie.definition) {
            streakTextIndex = streakTextIndex || currTextIndex;
            currPlaceInTrie = nextPlaceInTrie;
        } else {
            streakTextIndex = streakTextIndex || currTextIndex;
            const end = currTextIndex + currWord.length;
            const oldPart = text.substring(streakTextIndex, end);
            const linkText = `<a class="dict-link" href="${nextPlaceInTrie.definition.link}">${oldPart}</a>`;
            text = text.substring(0, streakTextIndex) + linkText + text.substring(end);
            currTextIndex += linkText.length - oldPart.length + 1;
            continue;
        }

        currTextIndex += currWord.length + 1;
    }

    if (originalText !== text) {
        const parentChildrenArray = node.children;
        const indexOfTextNodeInParent = parentChildrenArray.findIndex((n) => n.value === originalText);
        parentChildrenArray.splice(indexOfTextNodeInParent, 1, {
            type: 'HTML',
            value: text
        });
    }
}