First pass test matches ES6 modules as CommonJS modules making namedExports unusable

[qgustavor]

From the source the first time test detects using an simple regular expression could be a CommonJS module, trying to find expressions like "require" and "exports". As it's a simple test sometimes it matches those expressions in strings and comments (example: "required" from Apache License), making it try to transform the file as a CommonJS module.

When transforming the file it ends up not finding any exports and normally it returns null, except when namedExports is used. Maybe it can be changed to a warning and/or the first pass test me improved in some way to ignore strings and comments.

[Rich-Harris]

Thanks! Was a simple typo – fixed in 2.2.1.