unnecessary_library_directive

Library directives without comments or annotations should be avoided.

The analyzer produces this diagnostic when a library directive doesn't have a documentation comment or any annotations.

If no documentation comment or annotation precedes the library directive, then either it's unnecessary or the documentation comment and/or annotations are misplaced and should be moved.

The following code produces this diagnostic because the library directive doesn't have a documentation comment or annotation:

library;
​
class C {}

The following code produces this diagnostic because the library's documentation comment is below the library directive:

library;
​
/// This library provides the [C] class.
​
/// The [C] class.
class C {}

If you don't want to add a documentation comment or annotation to the library, then remove the library directive:

class C {}

If you intend to add a documentation comment or annotation, then add or move it to the library directive:

/// This library provides the [C] class.
library;
​
/// The [C] class.
class C {}