fix: make led panel controls write to sysfs reliably

test_led_panel.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+import json
+import tempfile
+import threading
+import urllib.request
+from pathlib import Path
+from led_panel import Handler, ThreadingHTTPServer
+import led_panel
+
+
+def req(port, path, body=None):
+    data = None
+    headers = {}
+    if body is not None:
+        data = json.dumps(body).encode()
+        headers['Content-Type'] = 'application/json'
+    r = urllib.request.Request(f'http://127.0.0.1:{port}{path}', data=data, headers=headers)
+    with urllib.request.urlopen(r, timeout=5) as resp:
+        return json.loads(resp.read().decode())
+
+
+def main():
+    with tempfile.TemporaryDirectory() as td:
+        root = Path(td)
+        d = root / 'blue:wan'
+        d.mkdir()
+        (d / 'brightness').write_text('0')
+        (d / 'max_brightness').write_text('1')
+        (d / 'trigger').write_text('[none] timer')
+        (d / 'delay_on').write_text('500')
+        (d / 'delay_off').write_text('500')
+        led_panel.LED_ROOT = root
+        httpd = ThreadingHTTPServer(('127.0.0.1', 0), Handler)
+        port = httpd.server_address[1]
+        t = threading.Thread(target=httpd.serve_forever, daemon=True)
+        t.start()
+        try:
+            leds = req(port, '/api/leds')
+            assert leds['ok'] and leds['leds'][0]['name'] == 'blue:wan'
+            b = req(port, '/api/brightness', {'name':'blue:wan','value':1})
+            assert b['ok'] and (d / 'brightness').read_text() == '1'
+            tr = req(port, '/api/trigger', {'name':'blue:wan','trigger':'timer'})
+            assert tr['ok']
+            assert (d / 'trigger').read_text() == 'timer'
+            delay = req(port, '/api/delay', {'name':'blue:wan','field':'delay_on','value':123})
+            assert delay['ok'] and (d / 'delay_on').read_text() == '123'
+            print('OK: API write regression passed')
+        finally:
+            httpd.shutdown()
+
+if __name__ == '__main__':
+    main()