chore: Move editor into codebase (#2930)

shared/editor/nodes/HorizontalRule.ts

@@ -0,0 +1,80 @@
+import Token from "markdown-it/lib/token";
+import { InputRule } from "prosemirror-inputrules";
+import { NodeSpec, NodeType, Node as ProsemirrorNode } from "prosemirror-model";
+import { EditorState, Transaction } from "prosemirror-state";
+import { MarkdownSerializerState } from "../lib/markdown/serializer";
+import Node from "./Node";
+
+export default class HorizontalRule extends Node {
+  get name() {
+    return "hr";
+  }
+
+  get schema(): NodeSpec {
+    return {
+      attrs: {
+        markup: {
+          default: "---",
+        },
+      },
+      group: "block",
+      parseDOM: [{ tag: "hr" }],
+      toDOM: (node) => {
+        return [
+          "hr",
+          { class: node.attrs.markup === "***" ? "page-break" : "" },
+        ];
+      },
+    };
+  }
+
+  commands({ type }: { type: NodeType }) {
+    return (attrs: Record<string, any>) => (
+      state: EditorState,
+      dispatch: (tr: Transaction) => void
+    ) => {
+      dispatch(
+        state.tr.replaceSelectionWith(type.create(attrs)).scrollIntoView()
+      );
+      return true;
+    };
+  }
+
+  keys({ type }: { type: NodeType }) {
+    return {
+      "Mod-_": (state: EditorState, dispatch: (tr: Transaction) => void) => {
+        dispatch(state.tr.replaceSelectionWith(type.create()).scrollIntoView());
+        return true;
+      },
+    };
+  }
+
+  inputRules({ type }: { type: NodeType }) {
+    return [
+      new InputRule(/^(?:---|___\s|\*\*\*\s)$/, (state, match, start, end) => {
+        const { tr } = state;
+
+        if (match[0]) {
+          const markup = match[0].trim();
+          tr.replaceWith(start - 1, end, type.create({ markup }));
+        }
+
+        return tr;
+      }),
+    ];
+  }
+
+  toMarkdown(state: MarkdownSerializerState, node: ProsemirrorNode) {
+    state.write(`\n${node.attrs.markup}`);
+    state.closeBlock(node);
+  }
+
+  parseMarkdown() {
+    return {
+      node: "hr",
+      getAttrs: (tok: Token) => ({
+        markup: tok.markup,
+      }),
+    };
+  }
+}