fix: highlight-lines provided with node.meta (#45)

Author: peterpeterparker

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Fix
 
 - no language provided results in an `undefined` value for the attribute highlight-lines ([#40](https://github.com/deckgo/gatsby-remark-highlight-code/issues/40))
+- highlight-lines information might be provided with the `node.lang` but als with `node.meta`
 
 # 3.0.0 (2021-05-22)
 

tests/mocks.js

@@ -10,10 +10,15 @@ const typescriptLangNode = {
 const typescriptWithLinesGroupNode = {
   lang: "typescript{3,4, 5-9, 22-45}",
 };
+const dartLangMetaNode = {
+  lang: "dart{3",
+  meta: ",4,5}",
+};
 
 module.exports = {
   dartLangNode,
   dartLangWithSpacesNode,
   typescriptLangNode,
   typescriptWithLinesGroupNode,
+  dartLangMetaNode,
 };

utils.js

@@ -7,11 +7,15 @@ const _ = require(`lodash`);
  * which is compatible with the <deckdeckgo-highlight-code> component (https://docs.deckdeckgo.com/?path=/story/components-highlight-code--highlight-code)
  * @param {Markdown Node} node
  */
-const parseLanguageAndHighlightedLines = (node) => {
+const parseLanguageAndHighlightedLines = ({lang: nodeLang, meta}) => {
   const highlightLinesRegex = /{(.*?)}/g;
-  let lang = node.lang;
+
+  const joinedNodeLang = `${nodeLang}${meta !== null && meta !== undefined ? meta : ''}`
+
+  let lang = joinedNodeLang;
   let highlightLines = "";
-  const regexExecResults = highlightLinesRegex.exec(node.lang);
+  const regexExecResults = highlightLinesRegex.exec(joinedNodeLang);
+
   if (!regexExecResults) { // no lines to highlight
     return {
       lang,

utils.test.js

@@ -2,7 +2,7 @@ const {
   dartLangNode,
   dartLangWithSpacesNode,
   typescriptLangNode,
-  typescriptWithLinesGroupNode,
+  typescriptWithLinesGroupNode, dartLangMetaNode,
 } = require("./tests/mocks");
 const { parseLanguageAndHighlightedLines, parseNodeHtml } = require("./utils");
 
@@ -106,5 +106,8 @@ describe("languages extraction", () => {
             parseLanguageAndHighlightedLines(typescriptWithLinesGroupNode)
                 .highlightLines
         ).toBe("3 4 5,9 22,45");
+        expect(parseLanguageAndHighlightedLines(dartLangMetaNode).highlightLines).toBe(
+            "3 4 5"
+        );
     });
 });