From 777e460fd0f04d3377393e4d5d240e36056e96d0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Fri, 16 Oct 2026 16:10:02 -0400
Subject: [PATCH] Fill in block validation messages' placeholders

---
 apps/cli/ai/block-validator.ts | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/apps/cli/ai/block-validator.ts b/apps/cli/ai/block-validator.ts
index defad741e2..d41d2ceb7c 100644
--- a/apps/cli/ai/block-validator.ts
+++ b/apps/cli/ai/block-validator.ts
@@ -72,6 +72,18 @@ export async function validateBlocks(
 				};
 			}
 
+			// Block validation logs console-style messages: a format string whose
+			// %s / %o / %d placeholders take the arguments that follow it.
+			function formatIssue( args: any[] ): string {
+				const show = ( value: any ) =>
+					typeof value === 'object' ? JSON.stringify( value ) : String( value );
+				const rest = args.slice( 1 );
+				const text = String( args[ 0 ] ?? '' ).replace( /%[sodif]/g, ( placeholder ) =>
+					rest.length ? show( rest.shift() ) : placeholder
+				);
+				return [ text, ...rest.map( show ) ].join( ' ' ).slice( 0, 600 );
+			}
+
 			function extractIssues( validationIssues: any[] ): string[] {
 				const issues: string[] = [];
 				for ( const issue of validationIssues ) {
@@ -80,15 +92,7 @@ export async function validateBlocks(
 						// Skip the verbose "Block validation failed for `name`" summary —
 						// the per-attribute messages that follow are more useful.
 						if ( ! msg.startsWith( 'Block validation failed' ) ) {
-							issues.push(
-								issue.args
-									.map( ( a: any ) =>
-										typeof a === 'object'
-											? JSON.stringify( a ).slice( 0, 200 )
-											: String( a ).slice( 0, 500 )
-									)
-									.join( ' ' )
-							);
+							issues.push( formatIssue( issue.args ) );
 						}
 					}
 				}