Anders Kaseorg 719546641f js: Convert a.indexOf(…) !== -1 to a.includes(…). ...

Babel polyfills this for us for Internet Explorer.

import * as babelParser from "recast/parsers/babel";
import * as recast from "recast";
import * as tsParser from "recast/parsers/typescript";
import { builders as b, namedTypes as n } from "ast-types";
import K from "ast-types/gen/kinds";
import fs from "fs";
import path from "path";
import process from "process";

const checkExpression = (node: n.Node): node is K.ExpressionKind =>
  n.Expression.check(node);

for (const file of process.argv.slice(2)) {
  console.log("Parsing", file);
  const ast = recast.parse(fs.readFileSync(file, { encoding: "utf8" }), {
    parser: path.extname(file) === ".ts" ? tsParser : babelParser,
  });
  let changed = false;

  recast.visit(ast, {
    visitBinaryExpression(path) {
      const { operator, left, right } = path.node;
      if (
        n.CallExpression.check(left) &&
        n.MemberExpression.check(left.callee) &&
        !left.callee.computed &&
        n.Identifier.check(left.callee.property) &&
        left.callee.property.name === "indexOf" &&
        left.arguments.length === 1 &&
        checkExpression(left.arguments[0]) &&
        ((["===", "!==", "==", "!=", ">", "<="].includes(operator) &&
          n.UnaryExpression.check(right) &&
          right.operator == "-" &&
          n.Literal.check(right.argument) &&
          right.argument.value === 1) ||
          ([">=", "<"].includes(operator) &&
            n.Literal.check(right) &&
            right.value === 0))
      ) {
        const test = b.callExpression(
          b.memberExpression(left.callee.object, b.identifier("includes")),
          [left.arguments[0]]
        );
        path.replace(
          ["!==", "!=", ">", ">="].includes(operator)
            ? test
            : b.unaryExpression("!", test)
        );
        changed = true;
      }
      this.traverse(path);
    },
  });

  if (changed) {
    console.log("Writing", file);
    fs.writeFileSync(file, recast.print(ast).code, { encoding: "utf8" });
  }
}

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

2020-02-10 14:08:12 -08:00

7.1 KiB

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