Merge pull request #217 from venthur/fix_devserver

fixed devserver

CHANGELOG.md

@@ -1,9 +1,10 @@
 # Changelog
 
-## unreleased
+## [unreleased]
 
+* Fixed devsever so it does not crash anymore when the (re-)build fails
 * dropped support for Python 3.8 and 3.9
-* added Python 3.13 to CI test suite
+* updated dependencies
 
 ## [2.2.1] -- 2023-11-11
 

blag/devserver.py

@@ -49,7 +49,7 @@ def get_last_modified(dirs: list[str]) -> float:
     return last_mtime
 
 
-def autoreload(args: argparse.Namespace) -> NoReturn:
+def autoreload(args: argparse.Namespace, wait: int=1) -> NoReturn:
     """Start the autoreloader.
 
     This method monitors the given directories for changes (i.e. the
@@ -63,6 +63,9 @@ def autoreload(args: argparse.Namespace) -> NoReturn:
     ----------
     args
         contains the input-, template- and static dir
+    wait
+        number of seconds the devsever waits before checking for updated
+        content
 
     """
     dirs = [args.input_dir, args.template_dir, args.static_dir]
@@ -71,12 +74,18 @@ def autoreload(args: argparse.Namespace) -> NoReturn:
     # loop to avoid serving stale contents
     last_mtime = 0.0
     while True:
-        mtime = get_last_modified(dirs)
-        if mtime > last_mtime:
-            last_mtime = mtime
-            logger.info("Change detected, rebuilding...")
-            blag.build(args)
-        time.sleep(1)
+        # make sure the devsever does not crash when the build fails with an
+        # exception
+        try:
+            mtime = get_last_modified(dirs)
+            if mtime > last_mtime:
+                last_mtime = mtime
+                logger.info("Change detected, rebuilding...")
+                blag.build(args)
+            time.sleep(wait)
+        except Exception:
+            logger.exception("Error occurred during rebuild:")
+            logger.info("Devserver did not crash, you may continue editing.")
 
 
 def serve(args: argparse.Namespace) -> None:

tests/test_devserver.py

@@ -4,10 +4,10 @@ import threading
 import time
 from argparse import Namespace
 
-import pytest
-
 from blag import devserver
 
+WAITTIME = 0.1
+
 
 def test_get_last_modified(cleandir: str) -> None:
     """Test get_last_modified."""
@@ -15,13 +15,13 @@ def test_get_last_modified(cleandir: str) -> None:
     t1 = devserver.get_last_modified(["content"])
 
     # wait a bit, create a file and measure again
-    time.sleep(0.1)
+    time.sleep(WAITTIME)
     with open("content/test", "w") as fh:
         fh.write("boo")
     t2 = devserver.get_last_modified(["content"])
 
     # wait a bit and take time again
-    time.sleep(0.1)
+    time.sleep(WAITTIME)
     t3 = devserver.get_last_modified(["content"])
 
     assert t2 > t1
@@ -36,14 +36,14 @@ def test_autoreload_builds_immediately(args: Namespace) -> None:
 
     t = threading.Thread(
         target=devserver.autoreload,
-        args=(args,),
+        args=(args, WAITTIME),
         daemon=True,
     )
     t0 = devserver.get_last_modified(["build"])
     t.start()
     # try for 5 seconds...
     for i in range(5):
-        time.sleep(1)
+        time.sleep(WAITTIME)
         t1 = devserver.get_last_modified(["build"])
         print(t1)
         if t1 > t0:
@@ -51,14 +51,11 @@ def test_autoreload_builds_immediately(args: Namespace) -> None:
     assert t1 > t0
 
 
-@pytest.mark.filterwarnings(
-    "ignore::pytest.PytestUnhandledThreadExceptionWarning"
-)
 def test_autoreload(args: Namespace) -> None:
     """Test autoreload."""
     t = threading.Thread(
         target=devserver.autoreload,
-        args=(args,),
+        args=(args, WAITTIME),
         daemon=True,
     )
     t.start()
@@ -71,8 +68,32 @@ def test_autoreload(args: Namespace) -> None:
 
     # try for 5 seconds to see if we rebuild once...
     for i in range(5):
-        time.sleep(1)
+        time.sleep(WAITTIME)
         t1 = devserver.get_last_modified(["build"])
         if t1 > t0:
             break
     assert t1 > t0
+
+
+def test_autoreload_does_not_crash(args: Namespace) -> None:
+    """Test autoreload does not crash if build fails."""
+    t = threading.Thread(
+        target=devserver.autoreload,
+        args=(args, WAITTIME),
+        daemon=True,
+    )
+    t.start()
+
+    t0 = devserver.get_last_modified(["build"])
+
+    # create a file that causes build to crash
+    with open("content/test.md", "w") as fh:
+        fh.write("date: ")
+
+    # try for 5 seconds to see if we rebuild once...
+    for i in range(5):
+        time.sleep(WAITTIME)
+        t1 = devserver.get_last_modified(["build"])
+        if t1 > t0:
+            break
+    assert t.is_alive()