Rustdoc does not compile code pieces if they are not separated from the surrounding text

[netvl]

The following is a perfectly valid Markdown, however, Rustdoc does not compile the piece of code (and, naturally, it is not run as a test with cargo test):

/// This is a test:
/// ```rust
/// let x = SomeUnknownStructure::new();
/// ```

This, however, does work:

/// This is a test:
///
/// ```rust
/// let x = SomeUnknownStructure::new();
/// ```

(that is, it fails to compile due to unknown symbol SomeUnknownStructure).

Note the empty line before the code block in the doc comment.

[Aatch]

Does it render correctly? If not it may be a bug in the mardown parser.

[netvl]

It looks like that it also renders incorrectly:

This is for the first snippet from the original post, the second snippet looks correctly.

[sfackler]

This is how at least some markdown parsers work - without a double line break before the tick marks, it's treated as part of the previous paragraph.

[Aatch]

The decision now then is whether we consider this working-as-expected or an actual bug?

[steveklabnik]

CommonMark says

A fenced code block may interrupt a paragraph, and does not require a blank line either before or after.

http://spec.commonmark.org/0.22/#code-fence

So I would argue it is a bug.

[insaneinside]

Also affects lists.

In CommonMark, a list can interrupt a paragraph. That is, no blank line is needed to separate a paragraph from a following list:

http://spec.commonmark.org/0.24/#lists

[Mark-Simulacrum]

With -Zunstable-options --enable-commonmark, rustdoc emits the following today, so I'm going to close this.

WARNING: test.rs - main (line 2) Code block is not currently run as a test, but will in future versions of rustdoc. Please ensure this code block is a runnable test, or use the `ignore` directive.

/// This is a test:
/// ```rust
/// let x = SomeUnknownStructure::new();
/// ```
pub fn main() {}