feat: Adds the ability to support horizontal rule in article editor

src/index.js

@@ -8,6 +8,7 @@ import Placeholder from "./Placeholder";
 import {
   listInputRules,
   linksInputRules,
+  hrInputRules,
   blocksInputRule,
   baseKeyMaps,
   textFormattingInputRules,
@@ -39,6 +40,7 @@ export const buildEditor = ({
   blocksInputRule(schema),
   textFormattingInputRules(schema),
   linksInputRules(schema),
+  hrInputRules(schema),
   listInputRules(schema),
   dropCursor(),
   gapCursor(),

src/rules/hr.js

@@ -0,0 +1,40 @@
+import { inputRules } from 'prosemirror-inputrules';
+import { safeInsert } from 'prosemirror-utils';
+import { createInputRule } from '../utils';
+
+function createHorizontalRuleInputRule(type) {
+  return createInputRule(
+    /^(?:---|___|\*\*\*)\s$/, // Ensures rule is triggered with space after "---", "___", or "***"
+    (state, match, start, end) => {
+      if (!match[0]) {
+        return null; // If no match found, return null
+      }
+
+      // Deletes the matched sequence including the space
+      let tr = state.tr.delete(start, end);
+      const hrPos = start; // Position where the horizontal rule should be inserted
+
+      // Insert the horizontal rule at the position
+      tr = safeInsert(type.create(), hrPos)(tr);
+
+      // Insert a paragraph node after the horizontal rule
+      tr = safeInsert(state.schema.nodes.paragraph.create(), tr.mapping.map(hrPos + 1))(tr);
+
+      return tr;
+    }
+  );
+}
+
+export function hrInputRules(schema) {
+  if (!schema.nodes.horizontal_rule) {
+    return null; // Ensures that horizontal_rule is part of the schema
+  }
+
+  const hrRule = createHorizontalRuleInputRule(schema.nodes.horizontal_rule);
+
+  return inputRules({
+    rules: [hrRule],
+  });
+}
+
+export default hrInputRules;

src/rules/index.js

@@ -1,6 +1,7 @@
 export { listInputRules } from './lists';
 export { linksInputRules } from './links';
 export { blocksInputRule } from './blocks';
+export { hrInputRules } from './hr';
 export { baseKeyMaps } from '../keymap';
 
 export { textFormattingInputRules } from './marks';

src/schema/markdown/articleParser.js

@@ -21,7 +21,7 @@ export const articleSchemaToMdMapping = {
 export const articleMdToPmMapping = {
   ...baseNodesMdToPmMapping,
   ...baseMarksMdToPmMapping,
-  hr: { node: 'rule' },
+  hr: { node: 'horizontal_rule' },
   heading: {
     block: 'heading',
     attrs: tok => ({ level: +tok.tag.slice(1) }),
@@ -46,6 +46,7 @@ md.enable([
   'entity',
   // Process escaped chars and hardbreaks
   'escape',
+  'hr',
 ]);
 
 export class ArticleMarkdownTransformer {
@@ -58,7 +59,7 @@ export class ArticleMarkdownTransformer {
         }
       }
     });
-
+    
     this.markdownParser = new MarkdownParser(
       schema,
       tokenizer,