test-repo/website/static/prettier-plugin-doc-explorer.mjs

import prettierPackageManifest from "./lib/package-manifest.mjs";
import * as prettier from "./lib/prettier/standalone.mjs";

const builderNames = new Set(Object.keys(prettier.doc.builders));

const parserName = "doc-explorer";
const languageName = "Doc explorer";
const astFormat = parserName;

const expressionParserName = "__js_expression";
async function getJsExpressionParser() {
  const plugin = prettierPackageManifest.plugins.find((plugin) =>
    plugin.parsers?.includes(expressionParserName),
  );
  const pluginModule = await import(`./lib/${plugin.file}`);
  return pluginModule.parsers[expressionParserName];
}

// `Symbol.for('description')`
function isSymbol(node) {
  return (
    node.type === "CallExpression" &&
    node.callee.type === "MemberExpression" &&
    !node.callee.computed &&
    !node.callee.optional &&
    node.callee.object.type === "Identifier" &&
    node.callee.object.name === "Symbol" &&
    node.callee.property.type === "Identifier" &&
    node.callee.property.name === "for" &&
    node.arguments.length === 1 &&
    node.arguments[0].type === "StringLiteral"
  );
}

function validateNode(node) {
  if (!node?.type) {
    return;
  }

  if (node.type === "ObjectExpression") {
    for (const property of node.properties) {
      if (
        property.type !== "ObjectProperty" ||
        property.computed ||
        property.shorthand ||
        property.method
      ) {
        throw new Error("Unexpected object property.");
      }

      const { value } = property;

      if (isSymbol(value)) {
        continue;
      }

      validateNode(value);
    }
    return;
  }

  if (node.type === "Identifier" && !builderNames.has(node.name)) {
    throw new Error(`Unexpected identifier name '${node.name}'.`);
  }

  for (const value of Object.values(node)) {
    const children = Array.isArray(value) ? value : [value];

    for (const child of children) {
      validateNode(child);
    }
  }
}

let expressionParser;
async function validateDoc(text) {
  expressionParser ??= await getJsExpressionParser();

  const ast = expressionParser.parse(text);
  if (ast.type !== "JsExpressionRoot") {
    throw new Error("Invalid doc");
  }

  validateNode(ast.node);
}

async function parse(text) {
  await validateDoc(text);

  const value = new Function(
    `{ ${Object.keys(prettier.doc.builders)} }`,
    `const result = (${text || "''"}\n); return result;`,
  )(prettier.doc.builders);

  return { value };
}

export const parsers = {
  [parserName]: {
    parse,
    astFormat,
  },
};
export const printers = {
  [astFormat]: {
    print: ({ node }) => node.value,
  },
};

export const languages = [{ name: languageName, parsers: [parserName] }];