Templater update to handle html and inline erb

Update templater pre-processing approach to
flag (and thus mitigate) duplicate matches
during the "flag content as code" step

app/assets/javascripts/static_site_editor/services/templater.js

-const marker = 'sse';
 const ticks = '```';
+const marker = 'sse';
 const prefix = `${ticks} ${marker}\n`; // Space intentional due to https://github.com/nhn/tui.editor/blob/6bcec75c69028570d93d973aa7533090257eaae0/libs/to-mark/src/renderer.gfm.js#L26
 const postfix = `\n${ticks}`;
-const code = '.| |\\t|\\n(?!\\n)';
-const templatedRegex = new RegExp(`(^${prefix}(${code})+${postfix}$)`, 'gm');
-const embeddedRubyRegex = new RegExp(`(^<%(${code})+%>$)`, 'gm');
+const flagPrefix = `${marker}-${Date.now()}`;
+const template = `.| |\\t|\\n(?!(\\n|${flagPrefix}))`;
+const templatedRegex = new RegExp(`(^${prefix}(${template})+?${postfix}$)`, 'gm');
+
+const nonErbMarkupRegex = new RegExp(`^((<(?!%).+>){1}(${template})+(</.+>){1})$`, 'gm');
+const embeddedRubyBlockRegex = new RegExp(`(^<%(${template})+%>$)`, 'gm');
+const embeddedRubyInlineRegex = new RegExp(`(^.*[<|&lt;]%(${template})+$)`, 'gm');
+
+// Order is intentional (general to specific) where HTML markup is flagged first, then ERB blocks, then inline ERB
+// Order in combo with the `flag()` algorithm is used to mitigate potential duplicate pattern matches (ERB nested in HTML for example)
+const orderedPatterns = [nonErbMarkupRegex, embeddedRubyBlockRegex, embeddedRubyInlineRegex];
 
 const unwrap = source => {
   let text = source;
   const matches = text.match(templatedRegex);
+
   if (matches) {
     matches.forEach(match => {
-      const initial = match.replace(prefix, '').replace(postfix, '');
+      const initial = match.replace(`${prefix}`, '').replace(`${postfix}`, '');
       text = text.replace(match, initial);
     });
   }
+
   return text;
 };
 
+const flag = (source, patterns) => {
+  let text = source;
+  let id = 0;
+  const hash = {};
+
+  patterns.forEach(pattern => {
+    const matches = text.match(pattern);
+    if (matches) {
+      matches.forEach(match => {
+        const key = `${flagPrefix}${id}`;
+        text = text.replace(match, key);
+        hash[key] = match;
+        id += 1;
+      });
+    }
+  });
+
+  return { text, hash };
+};
+
 const wrap = source => {
-  let text = unwrap(source);
-  const matches = text.match(embeddedRubyRegex);
-  if (matches) {
-    matches.forEach(match => {
-      text = text.replace(match, `${prefix}${match}${postfix}`);
-    });
-  }
-  return text;
+  const { text, hash } = flag(unwrap(source), orderedPatterns);
+
+  let wrappedSource = text;
+  Object.entries(hash).forEach(([key, value]) => {
+    wrappedSource = wrappedSource.replace(key, `${prefix}${value}${postfix}`);
+  });
+
+  return wrappedSource;
 };
 
 export default { wrap, unwrap };

changelogs/unreleased/38791-templater-inline-erb.yml

+---
+title: Add pre-processing step so inline ERB and HTML syntax are wrapped in codeblocks for code vs. content editing in the static site editor's WYSIWYG mode.
+merge_request: 38791
+author:
+type: added

spec/frontend/static_site_editor/services/templater_spec.js

@@ -2,25 +2,42 @@
 import templater from '~/static_site_editor/services/templater';
 
 describe('templater', () => {
-  const source = `Some text
+  const source = `Below this line is a simple ERB (single-line erb block) example.
 
 <% some erb code %>
 
-Some more text
+Below this line is a complex ERB (multi-line erb block) example.
 
 <% if apptype.maturity && (apptype.maturity != "planned") %>
   <% maturity = "This application type is at the \"#{apptype.maturity}\" level of maturity." %>
 <% end %>
 
-With even text with indented code above.
+Below this line is a non-erb (single-line HTML) markup example that also has erb.
+
+<a href="<%= compensation_roadmap.role_path %>"><%= compensation_roadmap.role_path %></a>
+
+Below this line is a non-erb (multi-line HTML block) markup example that also has erb.
+
+<ul>
+<% compensation_roadmap.recommendation.recommendations.each do |recommendation| %>
+  <li><%= recommendation %></li>
+<% end %>
+</ul>
+
+Below this line is a block of HTML.
+
+<div>
+  <h1>Heading</h1>
+  <p>Some paragraph...</p>
+</div>
 `;
-  const sourceTemplated = `Some text
+  const sourceTemplated = `Below this line is a simple ERB (single-line erb block) example.
 
 \`\`\` sse
 <% some erb code %>
 \`\`\`
 
-Some more text
+Below this line is a complex ERB (multi-line erb block) example.
 
 \`\`\` sse
 <% if apptype.maturity && (apptype.maturity != "planned") %>
@@ -28,7 +45,30 @@ Some more text
 <% end %>
 \`\`\`
 
-With even text with indented code above.
+Below this line is a non-erb (single-line HTML) markup example that also has erb.
+
+\`\`\` sse
+<a href="<%= compensation_roadmap.role_path %>"><%= compensation_roadmap.role_path %></a>
+\`\`\`
+
+Below this line is a non-erb (multi-line HTML block) markup example that also has erb.
+
+\`\`\` sse
+<ul>
+<% compensation_roadmap.recommendation.recommendations.each do |recommendation| %>
+  <li><%= recommendation %></li>
+<% end %>
+</ul>
+\`\`\`
+
+Below this line is a block of HTML.
+
+\`\`\` sse
+<div>
+  <h1>Heading</h1>
+  <p>Some paragraph...</p>
+</div>
+\`\`\`
 `;
 
   it.each`
@@ -38,7 +78,7 @@ With even text with indented code above.
     ${'unwrap'} | ${sourceTemplated} | ${source}
     ${'unwrap'} | ${source}          | ${source}
   `(
-    'wraps $initial in a templated sse codeblock if $fn is wrap, unwraps otherwise',
+    'wraps $initial in a templated sse codeblocks if $fn is wrap, unwraps otherwise',
     ({ fn, initial, target }) => {
       expect(templater[fn](initial)).toMatch(target);
     },