AbstractPathAssert.hasContent ignores a single trailing newline

[rupert-madden-abbott]

Given a file named foo.txt with the following contents:

Hello, world!

The following assertions pass:

assertThat(Path.of("foo.txt"))
    .hasContent("Hello, world!")
    .hasContent("Hello, world!\r")
    .hasContent("Hello, world!\n")
    .hasContent("Hello, world!\r\n");

However, newlines elsewhere in the expected value are not ignored. For example, this assertion fails: assertThat(Path.of("foo.txt")).hasContent("\nHello, world"); with the following error:

java.lang.AssertionError: 
Path:
  foo.txt
read with charset UTF-8 does not have the expected content:

Missing content at line 1:
  [""]

Equally, multiple newlines are not ignored. For example, this assertion fails: assertThat(Path.of("foo.txt")).hasContent("Hello, world\n\n"); with the following error:

java.lang.AssertionError: 
Path:
  foo.txt
read with charset UTF-8 does not have the expected content:

Missing content at line 2:
  [""]

Finally, a trailing newline is also ignored in the actual value. For example, given a file named foo.txt with the following contents:

Hello, world!

The following assertions pass:

assertThat(Path.of("foo.txt"))
    .hasContent("Hello, world!")
    .hasContent("Hello, world!\r")
    .hasContent("Hello, world!\n")
    .hasContent("Hello, world!\r\n");

[rupert-madden-abbott]

Sorry this is the wrong repo. Reopened here: assertj/assertj#2993