ac7b09d57e
js: Convert _.map(a, …) to a.map(…).
...
And convert the corresponding function expressions to arrow style
while we’re here.
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, {
visitCallExpression(path) {
const { callee, arguments: args } = path.node;
if (
n.MemberExpression.check(callee) &&
!callee.computed &&
n.Identifier.check(callee.object) &&
callee.object.name === "_" &&
n.Identifier.check(callee.property) &&
callee.property.name === "map" &&
args.length === 2 &&
checkExpression(args[0]) &&
checkExpression(args[1])
) {
const [arr, fn] = args;
path.replace(
b.callExpression(b.memberExpression(arr, b.identifier("map")), [
n.FunctionExpression.check(fn) ||
n.ArrowFunctionExpression.check(fn)
? b.arrowFunctionExpression(
fn.params,
n.BlockStatement.check(fn.body) &&
fn.body.body.length === 1 &&
n.ReturnStatement.check(fn.body.body[0])
? fn.body.body[0].argument || b.identifier("undefined")
: fn.body
)
: fn,
])
);
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
Anders Kaseorg
Tim Abbott
Shubham Dhama
Andy Perez