57 lines
1.9 KiB
JavaScript
57 lines
1.9 KiB
JavaScript
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/**
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* A Remark plugin for escaping markdown entities.
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*
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* When markdown entities are entered in raw markdown, they don't appear as
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* characters in the resulting AST; for example, dashes surrounding a piece of
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* text cause the text to be inserted in a special node type, but the asterisks
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* themselves aren't present as text. Therefore, we generally don't expect to
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* encounter markdown characters in text nodes.
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*
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* However, the CMS visual editor does not interpret markdown characters, and
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* users will expect these characters to be represented literally. In that case,
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* we need to escape them, otherwise they'll be interpreted during
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* stringification.
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*/
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export default function remarkEscapeMarkdownEntities() {
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/**
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* Escape all occurrences of '[', '*', '_', '`', and '~'.
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*/
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function escapeCommonChars(text) {
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return text.replace(/[\[*_`~]/g, '\\$&');
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}
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/**
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* Runs escapeCommonChars, and also escapes '#' and '-' when found at the
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* beginning of any node's first child node.
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*/
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function escapeAllChars(text) {
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const partiallyEscapedMarkdown = escapeCommonChars(text);
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return partiallyEscapedMarkdown.replace(/^\s*([#-])/, '$`\\$1');
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}
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const transform = (node, index) => {
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const children = node.children && node.children.map(transform);
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/**
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* Escape characters in text and html nodes only. We store a lot of normal
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* text in html nodes to keep Remark from escaping html entities.
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*/
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if (['text', 'html'].includes(node.type)) {
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/**
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* Escape all characters if this is the first child node, otherwise only
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* common characters.
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*/
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const value = index === 0 ? escapeAllChars(node.value) : escapeCommonChars(node.value);
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return { ...node, value, children };
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}
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/**
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* Always return nodes with recursively mapped children.
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*/
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return {...node, children };
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};
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return transform;
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}
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