feat: External Secrets storage for credentials (#6477)

Github issue / Community forum post (link here to close automatically):

---------

Co-authored-by: Romain Minaud <romain.minaud@gmail.com>
Co-authored-by: Valya Bullions <valya@n8n.io>
Co-authored-by: Csaba Tuncsik <csaba@n8n.io>
Co-authored-by: Giulio Andreini <g.andreini@gmail.com>
Co-authored-by: Omar Ajoue <krynble@gmail.com>

packages/editor-ui/src/utils/expressions.ts

@@ -0,0 +1,12 @@
+import { ExpressionParser } from 'n8n-workflow';
+
+export const isExpression = (expr: string) => expr.startsWith('=');
+
+export const isTestableExpression = (expr: string) => {
+	return ExpressionParser.splitExpression(expr).every((c) => {
+		if (c.type === 'text') {
+			return true;
+		}
+		return /\$secrets(\.[a-zA-Z0-9_]+)+$/.test(c.text.trim());
+	});
+};

packages/editor-ui/src/utils/index.ts

@@ -9,3 +9,4 @@ export * from './typeGuards';
 export * from './typesUtils';
 export * from './userUtils';
 export * from './sourceControlUtils';
+export * from './expressions';