test: fix pyright strict-mode errors in tests/test_observable/ (batch 3) (#785)

* test: fix pyright strict-mode errors in tests/test_observable/ (batch 3)

Fix pyright errors in 25 test files in tests/test_observable/:
- Add 'from typing import NoReturn' import
- Annotate '_raise' functions with 'ex: Exception -> NoReturn' signature
- Fix callsites passing str to '_raise()' to wrap in Exception()
- Fix subscribe functions returning 'lambda: None' to return Disposable()
- Fix 'return dispose' to 'return Disposable(dispose)'
- Fix 'o.on_error(str)' calls to wrap strings in Exception()
- Fix 'do_action(on_next=action)' with zero-param action to accept one param
- Remove non-None return values from 'finally_action' callbacks

These changes allow tests/test_observable/ to eventually be removed
from the pyright exclude list in pyproject.toml.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* ci: trigger build

* style: fix ruff import order and line length in test_observable batch 3

Pre-commit hook failures from PR #785:
- Reorder `from typing import NoReturn` after `from datetime` in 3 files
- Wrap two long lines exceeding 88 chars in test_fromiterable.py and
  test_minby.py

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Dag Brattli <dag@brattli.net>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 4 people

tests/test_observable/test_bufferwithcount.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 from reactivex import operators as ops
 from reactivex.testing import ReactiveTest, TestScheduler
@@ -17,7 +18,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_create.py

@@ -1,6 +1,8 @@
 import unittest
+from typing import NoReturn
 
 import reactivex
+from reactivex.disposable import Disposable
 from reactivex.testing import ReactiveTest, TestScheduler
 
 on_next = ReactiveTest.on_next
@@ -17,7 +19,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: str) -> NoReturn:
     raise RxException(ex)
 
 
@@ -29,7 +31,7 @@ def _create():
             def subscribe(o, scheduler=None):
                 o.on_next(1)
                 o.on_next(2)
-                return lambda: None
+                return Disposable()
 
             return reactivex.create(subscribe)
 
@@ -43,9 +45,9 @@ def _create():
             def subscribe(o, scheduler=None):
                 o.on_completed()
                 o.on_next(100)
-                o.on_error("ex")
+                o.on_error(Exception("ex"))
                 o.on_completed()
-                return lambda: None
+                return Disposable()
 
             return reactivex.create(subscribe)
 
@@ -58,11 +60,11 @@ def test_create_error(self):
 
         def _create():
             def subscribe(o, scheduler=None):
-                o.on_error(ex)
+                o.on_error(Exception(ex))
                 o.on_next(100)
-                o.on_error("foo")
+                o.on_error(Exception("foo"))
                 o.on_completed()
-                return lambda: None
+                return Disposable()
 
             return reactivex.create(subscribe)
 
@@ -109,7 +111,7 @@ def action4(scheduler, state):
                 def dispose():
                     is_stopped[0] = True
 
-                return dispose
+                return Disposable(dispose)
 
             return reactivex.create(subscribe)
 
@@ -124,21 +126,21 @@ def dispose():
     def test_create_observer_throws(self):
         def subscribe(o, scheduler=None):
             o.on_next(1)
-            return lambda: None
+            return Disposable()
 
         with self.assertRaises(RxException):
             reactivex.create(subscribe).subscribe(lambda x: _raise("ex"))
 
         def subscribe2(o, scheduler=None):
-            o.on_error("exception")
-            return lambda: None
+            o.on_error(Exception("exception"))
+            return Disposable()
 
         with self.assertRaises(RxException):
             reactivex.create(subscribe2).subscribe(on_error=lambda ex: _raise("ex"))
 
         def subscribe3(o, scheduler=None):
             o.on_completed()
-            return lambda: None
+            return Disposable()
 
         with self.assertRaises(RxException):
             reactivex.create(subscribe3).subscribe(on_completed=lambda: _raise("ex"))

tests/test_observable/test_debounce.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 from reactivex import empty, never, throw
 from reactivex import operators as _
@@ -18,7 +19,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_defer.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 import reactivex
 from reactivex.testing import ReactiveTest, TestScheduler
@@ -18,7 +19,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_delay.py

@@ -1,6 +1,7 @@
 import logging
 import unittest
 from datetime import datetime, timezone
+from typing import NoReturn
 
 from reactivex.operators import delay
 from reactivex.testing import ReactiveTest, TestScheduler
@@ -23,7 +24,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_delaywithmapper.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 from reactivex import Observable, abc
 from reactivex import operators as ops
@@ -20,7 +21,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_distinct.py

@@ -1,5 +1,6 @@
 import math
 import unittest
+from typing import NoReturn
 
 from reactivex import operators as ops
 from reactivex.testing import ReactiveTest, TestScheduler
@@ -18,7 +19,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_distinctuntilchanged.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 import reactivex
 from reactivex import operators as ops
@@ -18,7 +19,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 
@@ -282,7 +283,7 @@ def test_distinct_until_changed_key_mapper_throws(self):
         )
 
         def create():
-            return xs.pipe(ops.distinct_until_changed(lambda x: _raise(ex)))
+            return xs.pipe(ops.distinct_until_changed(lambda x: _raise(Exception(ex))))
 
         results = scheduler.start(create)
         assert results.messages == [on_error(210, ex)]
@@ -296,7 +297,7 @@ def test_distinct_until_changed_comparer_throws(self):
 
         def create():
             return xs.pipe(
-                ops.distinct_until_changed(comparer=lambda x, y: _raise(ex)),
+                ops.distinct_until_changed(comparer=lambda x, y: _raise(Exception(ex))),
             )
 
         results = scheduler.start(create)

tests/test_observable/test_expand.py

@@ -1,4 +1,5 @@
 import unittest
+from typing import NoReturn
 
 from reactivex import operators as ops
 from reactivex.testing import ReactiveTest, TestScheduler
@@ -17,7 +18,7 @@ class RxException(Exception):
 
 
 # Helper function for raising exceptions within lambdas
-def _raise(ex):
+def _raise(ex: Exception) -> NoReturn:
     raise RxException(ex)
 
 

tests/test_observable/test_finally.py

@@ -19,7 +19,6 @@ def test_finally_only_called_once_empty(self):
 
         def action():
             invasserte_count[0] += 1
-            return invasserte_count
 
         some_observable = reactivex.empty().pipe(ops.finally_action(action))
 
@@ -36,7 +35,6 @@ def test_finally_empty(self):
         def create():
             def action():
                 invasserted[0] = True
-                return invasserted[0]
 
             return xs.pipe(ops.finally_action(action))
 
@@ -55,7 +53,6 @@ def test_finally_return(self):
         def create():
             def action():
                 invasserted[0] = True
-                return invasserted[0]
 
             return xs.pipe(ops.finally_action(action))
 
@@ -78,7 +75,6 @@ def test_finally_on_error(self):
         def create():
             def action():
                 invasserted[0] = True
-                return invasserted[0]
 
             return xs.pipe(ops.finally_action(action))