Add StringSubject isNotBlank or hasText about truth HOT 2 CLOSED

We generally recommend that you trim the string in question first if you want to do this, rather than having a separate method for it, e.g.

// uses a weird definition of whitespace that doesn't match Unicode's
assertThat(myString.trim()).isEmpty();

// matches Unicode definition of whitespace
assertThat(CharMatcher.whitespace().trimFrom(myString)).isEmpty();

We also avoid APIs that treat null and non-null values equivalently (as you suggest with "null -> is blank"). Thanks for the request, but I don't think we'll be adding this.

from truth.

If you only want to check that your string contains zero or more blanks and nothing else, you can use something like

assertThat(string).matches(" *");

with "\\s*" or "\\h*" as alternatives depending on exactly what you want "blank" to mean.

from truth.