chore: Move editor into codebase (#2930)

shared/editor/marks/Italic.ts

@@ -0,0 +1,46 @@
+import { toggleMark } from "prosemirror-commands";
+import { InputRule } from "prosemirror-inputrules";
+import { MarkSpec, MarkType } from "prosemirror-model";
+import { Command } from "../lib/Extension";
+import markInputRule from "../lib/markInputRule";
+import Mark from "./Mark";
+
+export default class Italic extends Mark {
+  get name() {
+    return "em";
+  }
+
+  get schema(): MarkSpec {
+    return {
+      parseDOM: [{ tag: "i" }, { tag: "em" }],
+      toDOM: () => ["em"],
+    };
+  }
+
+  inputRules({ type }: { type: MarkType }): InputRule[] {
+    return [
+      markInputRule(/(?:^|[\s])(_([^_]+)_)$/, type),
+      markInputRule(/(?:^|[^*])(\*([^*]+)\*)$/, type),
+    ];
+  }
+
+  keys({ type }: { type: MarkType }): Record<string, Command> {
+    return {
+      "Mod-i": toggleMark(type),
+      "Mod-I": toggleMark(type),
+    };
+  }
+
+  toMarkdown() {
+    return {
+      open: "*",
+      close: "*",
+      mixable: true,
+      expelEnclosingWhitespace: true,
+    };
+  }
+
+  parseMarkdown() {
+    return { mark: "em" };
+  }
+}