From 9d1c0bce1ac11a8769076297df256d2dfd250316 Mon Sep 17 00:00:00 2001
From: liamcottle <liam@liamcottle.com>
Date: Mon, 27 May 2024 16:01:11 +1200
Subject: [PATCH] force python to immediatly flush stdout and stderr streams so
 other programs such as nodejs can use immediately

---
 src/__init__.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 src/__init__.py

diff --git a/src/__init__.py b/src/__init__.py
new file mode 100644
index 0000000..24b56e9
--- /dev/null
+++ b/src/__init__.py
@@ -0,0 +1,30 @@
+import sys
+
+# NOTE: this class is required to be able to use print/log commands and have them flush to stdout and stderr immediately
+# without wrapper stdout and stderr, when using `childProcess.stdout.on('data', ...)` in NodeJS script, we never get
+# any events fired until the process exists. However, force flushing the streams does first the callbacks in NodeJS.
+
+
+# this class forces stream writes to be flushed immediately
+class ImmediateFlushingStreamWrapper:
+
+    def __init__(self, stream):
+        self.stream = stream
+
+    # force write to flush immediately
+    def write(self, data):
+        self.stream.write(data)
+        self.stream.flush()
+
+    # force writelines to flush immediately
+    def writelines(self, lines):
+        self.stream.writelines(lines)
+        self.stream.flush()
+
+    def __getattr__(self, attr):
+        return getattr(self.stream, attr)
+
+
+# wrap stdout and stderr with our custom wrapper
+sys.stdout = ImmediateFlushingStreamWrapper(sys.stdout)
+sys.stderr = ImmediateFlushingStreamWrapper(sys.stderr)