fix(iqb_exception): don't suppress KeyboardInterrupt (#124)

This diff ensures that hitting `^C` immediately interrupts the scripting
code no matter what it is doing.

Useful to interrupt a BigQuery query in a long batch immediately as
opposed to have all of them started and interrupted while running, which
burns the daily allowance (happened yesterday).

Author: bassosimone

library/src/iqb/scripting/iqb_exception.py

@@ -31,6 +31,10 @@ def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
+        if exc_type is None:
+            return False
+        if issubclass(exc_type, KeyboardInterrupt):
+            return False
         if exc_type:
             log.error("operation failed: %s", exc_value)
             _ = traceback

library/tests/iqb/scripting/iqb_exception_test.py

@@ -2,6 +2,8 @@
 
 from unittest.mock import patch
 
+import pytest
+
 from iqb.scripting import iqb_exception
 
 
@@ -29,3 +31,17 @@ def test_exception_sets_failed_and_logs(self) -> None:
         log.error.assert_called_once()
         assert log.error.call_args[0][0] == "operation failed: %s"
         assert str(log.error.call_args[0][1]) == "boom"
+
+    def test_keyboard_interrupt_not_suppressed(self) -> None:
+        interceptor = iqb_exception.Interceptor()
+
+        with (
+            patch("iqb.scripting.iqb_exception.log") as log,
+            pytest.raises(KeyboardInterrupt),
+            interceptor,
+        ):
+            raise KeyboardInterrupt()
+
+        assert interceptor.failed is False
+        assert interceptor.exitcode() == 0
+        log.error.assert_not_called()