How to chain multiple assertThat statement in AssertJ

Question

Here is an example:

assertThat(commentById.getId()).isNotNull();
assertThat(commentById.getContent()).isNotBlank();
assertThat(commentById.getAuthor()).isNotNull();
assertThat(commentById.getAuthor().getUsername()).isNotBlank();
assertThat(commentById.getAuthor().getAvatar()).isNotBlank();
assertThat(commentById.getAuthor().getId()).isNotNull();

Is there anyway to chain this into a single assertThat statement

---

Sorry for the unclear question. I mean, is there some fluent method calls to chain multiple assertThat statement together. Here is an example I can think of:

assertThat(commentById)
.isNotNull()
.and(Comment::getID).isNotNull()
.and(Comment::getContent).isNotBlank()
.and(Comment::getAuthor).is(author->{
         author.isNotNull()
        .and(User::getID).isNotNull()
        .and(User::getAvatar).isNotBlank()
        .and(User::getUsername).isNotBlank()
});

Stablish

How would "chaining" these statements help you? – Gabe

Please provide a sample of what you think it should do. – Gabe

sorry for the unclear question. I've updated my question. – Stablish

Answer 1

This is not possible at the moment, what is possible is to use extracting but that implies navigating from the current actual to the extracted one without being able to go back to the original actual.

Ostensible

Answer 2

You can utilize satisfies method:

assertThat(commentById.getId()).isNotNull();
assertThat(commentById.getContent()).isNotBlank();
assertThat(commentById.getAuthor()).isNotNull().satisfies(author -> {
    assertThat(author.getUsername()).isNotBlank();
    assertThat(author.getAvatar()).isNotBlank();
    assertThat(author.getId()).isNotNull();
});

This helps to eliminate repeating parts of code while testing nested structures.

If you want the commentById object itself to be tested by "one-liner", it is theoretically possible to apply same approach onto it (assertThat(commentById).satisfies(c -> {assertThat(c.getId()).isNotNull(); ...})), however I state it here only to literally answer your question, actually I don't see any benefit of such expression.

Topmost

Thanks, didn't came across this, just now. – Glossectomy

Answer 3

Try this

assertThat(myService.getById("sr2"))
    .returns("s2-new", from(MyClass::getField1))
    .returns("s2", from(MyClass::getField2))
    .returns(Boolean.TRUE, from(MyClass::getField));

Cassiterite