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()
});

How would "chaining" these statements help you? – Jim Garrison Jul 31 '18 at 05:56 — Jim Garrison, Jul 31 '18 at 05:56
Please provide a sample of what you think it should do. – Jim Garrison Jul 31 '18 at 06:01 — Jim Garrison, Jul 31 '18 at 06:01
sorry for the unclear question. I've updated my question. – cdxf Jul 31 '18 at 07:08 — cdxf, Jul 31 '18 at 07:08

score 17 · Answer 1 · answered Jul 22 '21 at 09:11

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.

Thanks, didn't came across this, just now. – Lukas Maruniak Jan 27 '23 at 20:29 — Lukas Maruniak, Jan 27 '23 at 20:29
This should be the accepted answer – Gabriel Aug 10 '23 at 11:04 — Gabriel, Aug 10 '23 at 11:04

score 9 · Accepted Answer · answered Aug 17 '18 at 18:04

9

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.

answered Aug 17 '18 at 18:04

Joel Costigliola

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How to chain multiple assertThat statement in AssertJ

2 Answers2