Note that `export default` no longer modifies `module.exports`, but simply
defines `exports.default`, so these two import styles will work:
import DefaultExport from "./export-default-module.js"; // preferred
var DefaultExport = require("./export-default-module.js").default;
but this style will no longer work:
var DefaultExport = require("./export-default-module.js");
Specific improvements:
- Parentheses are now stripped from commands that look like named classes
so that they will be treated as class declarations rather than as named
class expressions.
- When the `ecmascript` package is installed, `compileForShell` errors are
now exposed to the `evalCommand` callback.
- Instead of using `vm.runInThisContext` to parse and evaluate commands at
the same time, `evalCommand` now parses commands by creating a new
`vm.Script` and later evaluates them using `script.runInThisContext()`,
so that `SyntaxError`s can be reported immediately. Fixes#5131.
