Inline comments for dynamic imports are removed starting with rollup 1.4.0

[BryceMehring]

• Rollup Version: 1.7.3
• Operating System (or Browser): MacOS 10.13.6
• Node Version: v11.12.0

How Do We Reproduce?

Rollup 1.3.3 does not remove comments within dynamic import statements. Rollup 1.4.0 and above removes comments from dynamic import statements. For example:

import(/* webpackChunkName: "chunk-name" */ 'some-module')

the comment will be removed in the bundle

Expected Behavior

Comments within the dynamic import should not be removed in the bundle.

Actual Behavior

Comments are being removed within the dynamic module import.

[manucorporat]

Unfortunately we also have to support webpack and this is causing issues too. Here's a simple repo case: https://rollupjs.org/repl?version=1.9.0&shareable=JTdCJTIybW9kdWxlcyUyMiUzQSU1QiU3QiUyMm5hbWUlMjIlM0ElMjJtYWluLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMmltcG9ydCglMkYqJTIwd2VicGFja0NodW5rTmFtZSUzQSUyMCU1QyUyMmNodW5rLW5hbWUlNUMlMjIlMjAqJTJGJy4lMkZtYXRocy5qcycpLnRoZW4oZnVuY3Rpb24lMjAobWF0aHMpJTIwJTdCJTVDbiU1Q3Rjb25zb2xlLmxvZyhtYXRocy5zcXVhcmUoNSkpJTNCJTVDbiU1Q3Rjb25zb2xlLmxvZyhtYXRocy5jdWJlKDUpKSUzQiU1Q24lN0QpJTNCJTIyJTJDJTIyaXNFbnRyeSUyMiUzQXRydWUlN0QlMkMlN0IlMjJuYW1lJTIyJTNBJTIybWF0aHMuanMlMjIlMkMlMjJjb2RlJTIyJTNBJTIyaW1wb3J0JTIwc3F1YXJlJTIwZnJvbSUyMCcuJTJGc3F1YXJlLmpzJyUzQiU1Q24lNUNuZXhwb3J0JTIwJTdCZGVmYXVsdCUyMGFzJTIwc3F1YXJlJTdEJTIwZnJvbSUyMCcuJTJGc3F1YXJlLmpzJyUzQiU1Q24lNUNuZXhwb3J0JTIwZnVuY3Rpb24lMjBjdWJlJTIwKHglMjApJTIwJTdCJTVDbiU1Q3RyZXR1cm4lMjBzcXVhcmUoeCklMjAqJTIweCUzQiU1Q24lN0QlMjIlMkMlMjJpc0VudHJ5JTIyJTNBZmFsc2UlN0QlMkMlN0IlMjJuYW1lJTIyJTNBJTIyc3F1YXJlLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMmV4cG9ydCUyMGRlZmF1bHQlMjBmdW5jdGlvbiUyMHNxdWFyZSUyMCglMjB4JTIwKSUyMCU3QiU1Q24lNUN0cmV0dXJuJTIweCUyMColMjB4JTNCJTVDbiU3RCUyMiUyQyUyMmlzRW50cnklMjIlM0FmYWxzZSU3RCU1RCUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJmb3JtYXQlMjIlM0ElMjJlc20lMjIlMkMlMjJuYW1lJTIyJTNBJTIybXlCdW5kbGUlMjIlMkMlMjJhbWQlMjIlM0ElN0IlMjJpZCUyMiUzQSUyMiUyMiU3RCUyQyUyMmdsb2JhbHMlMjIlM0ElN0IlN0QlN0QlMkMlMjJleGFtcGxlJTIyJTNBbnVsbCU3RA==

[manucorporat]

@lukastaegert prepared a PR! #2797 :)