feat: Add patterns to insert current date and time into doc (#3309)

* feat: Add patterns to insert current date and time into doc

* Add commands to title input too

* lint: Remove console.log

shared/editor/plugins/DateTime.ts

@@ -0,0 +1,39 @@
+import { InputRule } from "prosemirror-inputrules";
+import {
+  getCurrentDateAsString,
+  getCurrentDateTimeAsString,
+  getCurrentTimeAsString,
+} from "../../utils/date";
+import Extension from "../lib/Extension";
+import { EventType } from "../types";
+
+/**
+ * An editor extension that adds commands to insert the current date and time.
+ */
+export default class DateTime extends Extension {
+  get name() {
+    return "date_time";
+  }
+
+  inputRules() {
+    return [
+      // Note: There is a space at the end of the pattern here otherwise the
+      //  /datetime rule can never be matched.
+      new InputRule(/\/date\s$/, ({ tr }, _match, start, end) => {
+        tr.delete(start, end).insertText(getCurrentDateAsString() + " ");
+        this.editor.events.emit(EventType.blockMenuClose);
+        return tr;
+      }),
+      new InputRule(/\/time$/, ({ tr }, _match, start, end) => {
+        tr.delete(start, end).insertText(getCurrentTimeAsString() + " ");
+        this.editor.events.emit(EventType.blockMenuClose);
+        return tr;
+      }),
+      new InputRule(/\/datetime$/, ({ tr }, _match, start, end) => {
+        tr.delete(start, end).insertText(`${getCurrentDateTimeAsString()} `);
+        this.editor.events.emit(EventType.blockMenuClose);
+        return tr;
+      }),
+    ];
+  }
+}