fix: end bun cluster log lines with a newline when log_date_format is set

lib/ProcessContainerBun.js

@@ -161,10 +161,11 @@ function exec(script, stds) {
             app_name : pm2_env.name
           }) + '\n';
         }
-        else if (pm2_env.log_date_format && dayjs)
-          log_data = `${dayjs().format(pm2_env.log_date_format)}: ${msg}`;
-        else
-          log_data = msg.endsWith('\n') ? msg : msg + '\n';
+        else {
+          const line = msg.endsWith('\n') ? msg : msg + '\n';
+          log_data = pm2_env.log_date_format && dayjs ?
+            `${dayjs().format(pm2_env.log_date_format)}: ${line}` : line;
+        }
 
         // Send the log message to the master process
         process.send({
@@ -197,10 +198,11 @@ function exec(script, stds) {
             app_name : pm2_env.name
           }) + '\n';
         }
-        else if (pm2_env.log_date_format && dayjs)
-          log_data = `${dayjs().format(pm2_env.log_date_format)}: ${msg}`;
-        else
-          log_data = msg.endsWith('\n') ? msg : msg + '\n';
+        else {
+          const line = msg.endsWith('\n') ? msg : msg + '\n';
+          log_data = pm2_env.log_date_format && dayjs ?
+            `${dayjs().format(pm2_env.log_date_format)}: ${line}` : line;
+        }
 
         // Send the log message to the master process
         process.send({

test/e2e/cli/bun.sh

@@ -29,4 +29,22 @@ sleep 1.5
 grep "Hello Typescript!" typescript.log
 spec "Should work on Typescript files in fork mode"
 
+########### cluster mode with --log-date-format keeps one entry per line
+$pm2 delete all
+
+>date-out.log
+>date-err.log
+
+$pm2 start echo-lines.ts -i 1 --log-date-format "YYYY" -o date-out.log -e date-err.log --merge-logs
+
+sleep 1.5
+
+[ "$(grep -c '^[0-9]\{4\}: line \(one\|two\)$' date-out.log)" -eq 2 ]
+spec "Should end each out log entry with a newline in cluster mode with --log-date-format"
+
+[ "$(grep -c '^[0-9]\{4\}: error \(one\|two\)$' date-err.log)" -eq 2 ]
+spec "Should end each error log entry with a newline in cluster mode with --log-date-format"
+
+rm -f date-out.log date-err.log
+
 $pm2 delete all

test/fixtures/interpreter/echo-lines.ts

@@ -0,0 +1,6 @@
+console.log('line one');
+console.log('line two');
+console.error('error one');
+console.error('error two');
+
+setInterval(() => {}, 1000);