feat(core): Add Tournament as the new default expression evaluator (#6964)

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

---------

Co-authored-by: Omar Ajoue <krynble@gmail.com>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/cli/src/ExpressionEvalator.ts

@@ -0,0 +1,14 @@
+import config from '@/config';
+import { ErrorReporterProxy, ExpressionEvaluatorProxy } from 'n8n-workflow';
+
+export const initExpressionEvaluator = () => {
+	ExpressionEvaluatorProxy.setEvaluator(config.getEnv('expression.evaluator'));
+	ExpressionEvaluatorProxy.setDifferEnabled(config.getEnv('expression.reportDifference'));
+	ExpressionEvaluatorProxy.setDiffReporter((expr) => {
+		ErrorReporterProxy.warn('Expression difference', {
+			extra: {
+				expression: expr,
+			},
+		});
+	});
+};

packages/cli/src/Server.ts

@@ -336,6 +336,9 @@ export class Server extends AbstractServer {
 			variables: {
 				limit: 0,
 			},
+			expressions: {
+				evaluator: config.getEnv('expression.evaluator'),
+			},
 			banners: {
 				dismissed: [],
 			},

packages/cli/src/commands/BaseCommand.ts

@@ -21,6 +21,7 @@ import { InternalHooks } from '@/InternalHooks';
 import { PostHogClient } from '@/posthog';
 import { License } from '@/License';
 import { ExternalSecretsManager } from '@/ExternalSecrets/ExternalSecretsManager.ee';
+import { initExpressionEvaluator } from '@/ExpressionEvalator';
 
 export abstract class BaseCommand extends Command {
 	protected logger = LoggerProxy.init(getLogger());
@@ -39,6 +40,7 @@ export abstract class BaseCommand extends Command {
 
 	async init(): Promise<void> {
 		await initErrorHandling();
+		initExpressionEvaluator();
 
 		process.once('SIGTERM', async () => this.stopProcess());
 		process.once('SIGINT', async () => this.stopProcess());

packages/cli/src/config/schema.ts

@@ -1199,6 +1199,21 @@ export const schema = {
 		},
 	},
 
+	expression: {
+		evaluator: {
+			doc: 'Expression evaluator to use',
+			format: ['tmpl', 'tournament'] as const,
+			default: 'tournament',
+			env: 'N8N_EXPRESSION_EVALUATOR',
+		},
+		reportDifference: {
+			doc: 'Whether to report differences in the evaluator outputs',
+			format: Boolean,
+			default: false,
+			env: 'N8N_EXPRESSION_REPORT_DIFFERENCE',
+		},
+	},
+
 	sourceControl: {
 		defaultKeyPairType: {
 			doc: 'Default SSH key type to use when generating SSH keys',