assemblyscript-prettier/src/replace.js

prettier for assemblyscript

import assemblyscript from "assemblyscript";

export const magic = "MAGIC_ASSEMBLYSCRIPT_PRETTIER_1996";
const prefix = "/*" + magic;
const postfix = magic + "*/";
const NodeKind = assemblyscript.NodeKind;

function visitDecorators(node) {
  let list = [];
  let _visit = (_node) => {
    switch (_node.kind) {
      case NodeKind.Source: {
        _node.statements.forEach((statement) => {
          _visit(statement);
        });
        break;
      }
      case NodeKind.ClassDeclaration:
      case NodeKind.InterfaceDeclaration:
      case NodeKind.NamespaceDeclaration: {
        _node.members.forEach((statement) => {
          _visit(statement);
        });
        break;
      }
    }
    if (_node.decorators) {
      list.push(
        ..._node.decorators.map((decorator) => {
          return {
            start: decorator.range.start,
            end: decorator.range.end,
          };
        })
      );
    }
  };
  _visit(node);
  return list;
}

/**
 *
 * @param {string} code
 * @returns {string}
 */
export function preProcess(code) {
  let parser = new assemblyscript.Parser();
  parser.parseFile(code, "pre_process.ts", false);
  let source = parser.sources[0];

  const decorators = visitDecorators(source);
  decorators.sort((a, b) => a.start - b.start);
  let cursor = 0;
  const removeDecoratorCodes = decorators.map((decorator) => {
    let s1 = code.slice(cursor, decorator.start);
    let s2 = code.slice(decorator.start, decorator.end);
    cursor = decorator.end;
    return `${s1}${prefix}${s2}`;
  });
  removeDecoratorCodes.push(code.slice(cursor));
  return removeDecoratorCodes.join(postfix);
}