Avoid empty last line in editable code blocks #1836
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@ehuss or others, would you be able to review this? I would love to help make mdBook look more uniform. |
ehuss
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Aug 9, 2022
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Before, a code block would always end with a final newline. The newline was added unconditionally by `hide_lines`. When the code block is syntax highlighted by highlight.js, this is not a problem, no empty line is added for a final trailing `\n` character. However, when the code block is editable and thus handled by the ACE editor, a trailing newline _is_ significant. I believe this issue is most closely described by ajaxorg/ace#2083 in the upstream repository. The effect of the way ACE handles newlines is that a code block like <pre> Some code </pre> will create an editor with _two_ lines, not just one. By trimming trailing whitespace, we ensure that we don’t accidentally create more lines in the ACE editor than necessary.
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Thanks for the review! |
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Before, a code block would always end with a final newline. The newline was added unconditionally by
hide_lines.When the code block is syntax highlighted by highlight.js, this is not a problem, no empty line is added for a final trailing
\ncharacter. However, when the code block is editable and thus handled by the ACE editor, a trailing newline is significant. I believe this issue is most closely described by ajaxorg/ace#2083 in the upstream repository.The effect of the way ACE handles newlines is that a code block like
will create an editor with two lines, not just one.
By trimming trailing whitespace, we ensure that we don’t accidentally create more lines in the ACE editor than necessary.
Before
After