SERVER-76620 Ensure golden output of each print() is newline-terminated

1 files changed, 13 insertions, 1 deletions

diff --git a/jstests/libs/golden_test.js b/jstests/libs/golden_test.js
index f3e218f1795..d7ce9f6d5a9 100644
--- a/jstests/libs/golden_test.js
+++ b/jstests/libs/golden_test.js
@@ -21,7 +21,19 @@ print = (() => {
     const original = print;
     return function print(...args) {
         // Imitate GlobalInfo::Functions::print::call.
-        const str = args.map(a => a == null ? '[unknown type]' : a).join(' ');
+        let str = args.map(a => a == null ? '[unknown type]' : a).join(' ');
+
+        // Make sure each print() call ends in a newline.
+        //
+        // From manual testing, it seems (print('a'), print('b')) behaves the same as
+        // (print('a\n'), print('b\n')); that behavior must be to ensure each print call appears on
+        // its own line for readability. In the context of golden testing, we want to match that
+        // behavior, and this also ensures the test output is a proper text file
+        // (newline-terminated).
+        if (str.slice(-1) !== '\n') {
+            str += '\n';
+        }
+
         _writeGoldenData(str);
 
         return original(...args);