try a fix

Author: nhsd-david-wass

tests/helpers/pnpm-helpers.ts

@@ -60,16 +60,14 @@ export async function runCreateLetter(options: {
   ];
 
   await new Promise<void>((resolve, reject) => {
-    let output = "";
     const child = spawn(cmd, args, {
       stdio: "inherit",
       cwd: root,
       shell: false,
     });
     child.stdout?.on("id", (id) => {
       const text = id.toString();
-      output += text;
-      process.stdout.write(output);
+      process.stdout.write(text);
     });
 
     child.on("close", (code) =>
@@ -127,7 +125,7 @@ export async function createSupplierData(options: {
     child.stdout?.on("id", (id) => {
       const text = id.toString();
       output += text;
-      process.stdout.write(output);
+      process.stdout.write(text);
     });
 
     child.on("close", (code) =>