1 files changed, 40 insertions, 0 deletions
diff --git a/app/assets/javascripts/static_site_editor/rich_content_editor/services/renderers/render_identifier_instance_text.js b/app/assets/javascripts/static_site_editor/rich_content_editor/services/renderers/render_identifier_instance_text.js
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+++ b/app/assets/javascripts/static_site_editor/rich_content_editor/services/renderers/render_identifier_instance_text.js
@@ -0,0 +1,40 @@
+import { buildTextToken, buildUneditableInlineTokens } from './build_uneditable_token';
+
+/*
+Use case examples:
+- Majority: two bracket pairs, back-to-back, each with content (including spaces)
+  - `[environment terraform plans][terraform]`
+  - `[an issue labelled `~"main:broken"`][broken-main-issues]`
+- Minority: two bracket pairs the latter being empty or only one pair with content (including spaces)
+  - `[this link][]`
+  - `[this link]`
+
+Regexp notes:
+  - `(?:\[.+?\]){1}`: Always one bracket pair with content (including spaces)
+  - `(?:\[\]|\[.+?\])?`: Optional second pair that may or may not contain content (including spaces)
+  - `(?!:)`: Never followed by a `:` which is reserved for identifier definition syntax (`[identifier]: /the-link`)
+  - Each of the three parts is non-captured, but the match as a whole is captured
+*/
+const identifierInstanceRegex = /((?:\[.+?\]){1}(?:\[\]|\[.+?\])?(?!:))/g;
+
+const isIdentifierInstance = (literal) => {
+  // Reset lastIndex as global flag in regexp are stateful (https://stackoverflow.com/a/11477448)
+  identifierInstanceRegex.lastIndex = 0;
+  return identifierInstanceRegex.test(literal);
+};
+
+const canRender = ({ literal }) => isIdentifierInstance(literal);
+
+const tokenize = (text) => {
+  const matches = text.split(identifierInstanceRegex);
+  const tokens = matches.map((match) => {
+    const token = buildTextToken(match);
+    return isIdentifierInstance(match) ? buildUneditableInlineTokens(token) : token;
+  });
+
+  return tokens.flat();
+};
+
+const render = (_, { origin }) => tokenize(origin().content);
+
+export default { canRender, render };