refactor.js

#!/usr/bin/env node

// Multi-purpose refactor script.
// Currently it only enforces that all Promise objects have a .fail().

const fs = require('fs');
const process = require('process');

const babelParser = require('@babel/parser');
const t = require('@babel/types');
const traverse = require('@babel/traverse').default;

if (process.argv.length != 4) {
  console.error(
    `Usage: ${process.argv[1]} <filename> <original filename>`,
  );
  process.exit(1);
}

const filename = process.argv[2];
const sourceFilename = process.argv[3];
const buf = fs.readFileSync(filename, 'utf8');
const isModule = sourceFilename.indexOf('/js/omegaup/') != -1;
const ast = (() => {
  try {
    return babelParser.parse(buf, {
      sourceType: isModule ? 'module' : 'script',
      sourceFilename: sourceFilename,
      plugins: ['typescript'],
    });
  } catch (e) {
    if (e instanceof SyntaxError) {
      const lines = buf.split('\n');
      // Do a best-effort attempt at getting the token involved in the error.
      // Just grab the non-whitespace characters at the point in which the error
      // occurred.
      const token = buf.slice(e.pos).match(/^(\S+)/)[1];
      console.error(
          `Syntax error in ${sourceFilename}:${e.loc.line}: ${e.message}\n`);
      console.error(`\t${lines[e.loc.line - 1]}`);
      console.error(
          `\t${''.padEnd(e.loc.column)}${''.padEnd(token.length, '^')}`);
    } else {
      console.log(e);
    }
    process.exit(1);
  }
})();


function hasRefactorLintDisableComment(path) {
  const comments = path.getStatementParent().node.trailingComments;
  if (!comments || comments.length == 0) {
    return false;
  }
  return comments[0].value.trim() == 'refactor-lint-disable';
}

const fixes = [];
const promiseVisitor = {
  CallExpression(path) {
    if (hasRefactorLintDisableComment(path)) {
      return;
    }
    const callee = path.node.callee;
    if (callee.type != 'MemberExpression') {
      return;
    }
    if (callee.property.name != 'then' && callee.property.name != 'catch') {
      return;
    }
    const p = path.getStatementParent();
    if (p.node.type != 'ExpressionStatement') {
      throw new Error('Unexpected statement type: ' + p.node.type);
    }
    if (callee.property.name == 'catch') {
      p.hasCatch = true;
    } else if (callee.property.name == 'then') {
      if (p.visited) {
        return;
      }
      p.visited = true;
      if (!p.hasCatch) {
        fixes.push({
          start: path.node.end,
          end: path.node.end,
          contents: '.catch(' + (isModule ? 'UI' : 'omegaup.UI') + '.apiError)',
        });
        p.hasCatch = true;
        valid = false;
      }
    }
  },
};
traverse(ast, promiseVisitor);

// From https://github.com/jquery/jquery/blob/2d4f53416e5f74fa98e0c1d66b6f3c285a12f0ce/src/selector-native.js#L212
const jQueryBooleanProperties = [
  'checked',
  'selected',
  'async',
  'autofocus',
  'autoplay',
  'controls',
  'defer',
  'disabled',
  'hidden',
  'ismap',
  'loop',
  'multiple',
  'open',
  'readonly',
  'required',
  'scoped',
];
const jQueryRemoveAttrVisitor = {
  CallExpression(path) {
    if (hasRefactorLintDisableComment(path)) {
      return;
    }
    let callee = path.node.callee;
    if (callee.type != 'MemberExpression') {
      return;
    }
    const identifier = callee.property;
    if (identifier.name != 'removeAttr') {
      return;
    }
    if (
      path.node.arguments.length != 1 ||
      path.node.arguments[0].type != 'StringLiteral'
    ) {
      return;
    }
    let attributeName = path.node.arguments[0].value;
    if (jQueryBooleanProperties.indexOf(attributeName) == -1) {
      return;
    }
    fixes.push({
      start: identifier.start - 1,
      end: path.node.end,
      contents: ".prop('" + attributeName + "', false)",
    });
  },
};
traverse(ast, jQueryRemoveAttrVisitor);

// From https://github.com/jquery/jquery/blob/305f193aa57014dc7d8fa0739a3fefd47166cd44/src/event/alias.js
const jQueryDeprecatedFunctions = [
  'blur',
  'focus',
  'focusin',
  'focusout',
  'resize',
  'scroll',
  'click',
  'dblclick',
  'mousedown',
  'mouseup',
  'mousemove',
  'mouseover',
  'mouseout',
  'mouseenter',
  'mouseleave',
  'change',
  'select',
  'submit',
  'keydown',
  'keypress',
  'keyup',
  'contextmenu',
];
const jQueryDeprecatedFunctionVisitor = {
  CallExpression(path) {
    if (hasRefactorLintDisableComment(path)) {
      return;
    }
    let callee = path.node.callee;
    if (callee.type != 'MemberExpression') {
      return;
    }
    const identifier = callee.property;
    if (jQueryDeprecatedFunctions.indexOf(identifier.name) == -1) {
      return;
    }
    if (path.node.arguments.length == 0) {
      // Excluding expressions that do not belong to jQuery
      if (callee.name != '$' && callee.name != 'jQuery') {
        return;
      }
      // This is a trigger.
      fixes.push({
        start: identifier.start,
        end: path.node.end,
        contents: "trigger('" + identifier.name + "')",
      });
      return;
    }
    // This is an event handler.
    while (callee.object && callee.object.type == 'CallExpression') {
      callee = callee.object.callee;
      if (callee.type != 'Identifier') {
        continue;
      }
      if (callee.name != '$' && callee.name != 'jQuery') {
        continue;
      }
      fixes.push({
        start: identifier.start,
        end: identifier.end + 1,
        contents: "on('" + identifier.name + "', ",
      });
      return;
    }
  },
};
traverse(ast, jQueryDeprecatedFunctionVisitor);

fixes.sort((a, b) => a.start - b.start);

// Manually write the results instead of relying on babel-generator.
// babel-generator moves stuff around too much :/
var lastPos = 0;
const fd = fs.openSync(filename, 'w');
for (var i = 0; i < fixes.length; i++) {
  fs.writeSync(fd, buf.slice(lastPos, fixes[i].start));
  fs.writeSync(fd, fixes[i].contents);
  lastPos = fixes[i].end;
}
fs.writeSync(fd, buf.slice(lastPos));
fs.closeSync(fd);