From 4f1632e3cd3b09cf53782b57133b21d770c41501 Mon Sep 17 00:00:00 2001
From: Bastian Venthur <venthur@debian.org>
Date: Sat, 6 Nov 2021 14:12:57 +0100
Subject: [PATCH] Immediately rebuild once when entering autoreload

---
 blag/devserver.py       |  7 ++++++-
 tests/test_devserver.py | 43 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/blag/devserver.py b/blag/devserver.py
index 2160709..c293633 100644
--- a/blag/devserver.py
+++ b/blag/devserver.py
@@ -55,6 +55,9 @@ def autoreload(args):
     last modified time). If the last modified time has changed, a
     rebuild is triggered.
 
+    A rebuild is also performed immediately when this method is called
+    to avoid serving stale contents.
+
     Parameters
     ----------
     args : argparse.Namespace
@@ -62,7 +65,9 @@ def autoreload(args):
     """
     dirs = [args.input_dir, args.template_dir, args.static_dir]
     logger.info(f'Monitoring {dirs} for changes...')
-    last_mtime = get_last_modified(dirs)
+    # make sure we trigger the rebuild immediately when we enter the
+    # loop to avoid serving stale contents
+    last_mtime = 0
     while True:
         mtime = get_last_modified(dirs)
         if mtime > last_mtime:
diff --git a/tests/test_devserver.py b/tests/test_devserver.py
index f06d45c..604a517 100644
--- a/tests/test_devserver.py
+++ b/tests/test_devserver.py
@@ -1,4 +1,5 @@
 import time
+import threading
 
 from blag import devserver
 
@@ -19,3 +20,45 @@ def test_get_last_modified(cleandir):
 
     assert t2 > t1
     assert t2 == t3
+
+
+def test_autoreload_builds_immediately(args):
+    # create a dummy file that can be build
+    with open('content/test.md', 'w') as fh:
+        fh.write('boo')
+
+    t = threading.Thread(target=devserver.autoreload,
+                         args=(args, ),
+                         daemon=True,)
+    t0 = devserver.get_last_modified(['build'])
+    t.start()
+    # try for 5 seconds...
+    for i in range(5):
+        time.sleep(1)
+        t1 = devserver.get_last_modified(['build'])
+        print(t1)
+        if t1 > t0:
+            break
+    assert t1 > t0
+
+
+def test_autoreload(args):
+    t = threading.Thread(target=devserver.autoreload,
+                         args=(args, ),
+                         daemon=True,)
+    t.start()
+
+    t0 = devserver.get_last_modified(['build'])
+
+    # create a dummy file that can be build
+    with open('content/test.md', 'w') as fh:
+        fh.write('boo')
+
+    # try for 5 seconds...
+    for i in range(5):
+        time.sleep(1)
+        t1 = devserver.get_last_modified(['build'])
+        print(t1)
+        if t1 > t0:
+            break
+    assert t1 > t0