Add unit tests to validate exception formatting of new Python syntax

These tests ensure that there are no unexpected errors during syntax
highlighting and local variable collection. However, this also shows
that the implementation can be improved. Some new keywords (such as
"match") are not recognized.

The addition of "--force-exclude" is necessary to prevent "black"
formatter from failing (despite "fmt: off") due to a parsing error
(caused by "--target-version py35" when the file contains a new
syntax).

.pre-commit-config.yaml

@@ -16,7 +16,7 @@ repos:
   rev: 23.7.0
   hooks:
   - id: black
-    args: [-l, '100', --target-version, py35]
+    args: [-l, '100', --target-version, py35, --force-exclude, tests/exceptions/source/modern/*]
 - repo: https://github.com/astral-sh/ruff-pre-commit
   rev: v0.0.286
   hooks:

tests/exceptions/output/modern/exception_group_catch.txt

@@ -0,0 +1,30 @@
+
+  + Exception Group Traceback (most recent call last):
+  |
+  |   File "tests/exceptions/source/modern/exception_group_catch.py", line 14, in a
+  |     raise ExceptionGroup("group", [ValueError(1)])
+  |
+  | ExceptionGroup: group (1 sub-exception)
+  +-+---------------- 1 ----------------
+    | ValueError: 1
+    +------------------------------------
+
+
+During handling of the above exception, another exception occurred:
+
+
+Traceback (most recent call last):
+
+  File "tests/exceptions/source/modern/exception_group_catch.py", line 25, in <module>
+    b()
+    └ <function b at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/exception_group_catch.py", line 21, in b
+    except* TypeError: a()
+                       └ <function a at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/exception_group_catch.py", line 15, in a
+    except* x as e: raise ValueError(2)
+            └ <class 'ValueError'>
+
+ValueError: 2

tests/exceptions/output/modern/f_string.txt

@@ -0,0 +1,11 @@
+
+Traceback (most recent call last):
+
+  File "tests/exceptions/source/modern/f_string.py", line 17, in <module>
+    hello()
+    └ <function hello at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/f_string.py", line 13, in hello
+    f"{name}" and f'{{ {f / 0} }}'
+
+ZeroDivisionError: division by zero

tests/exceptions/output/modern/match_statement.txt

@@ -0,0 +1,20 @@
+
+Traceback (most recent call last):
+
+  File "tests/exceptions/source/modern/match_statement.py", line 21, in <module>
+    match(1)
+    └ <function match at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/match_statement.py", line 18, in match
+    case y: case(x)
+    │    │  │    └ 1
+    │    │  └ <function case at 0xDEADBEEF>
+    │    └ 1
+    └ <function case at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/match_statement.py", line 11, in case
+    match y / 0:
+    │     └ 1
+    └ <function match at 0xDEADBEEF>
+
+ZeroDivisionError: division by zero

tests/exceptions/output/modern/positional_only_argument.txt

@@ -0,0 +1,20 @@
+
+Traceback (most recent call last):
+
+  File "tests/exceptions/source/modern/positional_only_argument.py", line 23, in <module>
+    main()
+    └ <function main at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/positional_only_argument.py", line 19, in main
+    foo(1, 2, c=3)
+    └ <function foo at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/positional_only_argument.py", line 15, in foo
+    def foo(a, /, b, *, c, **d): 1 / 0
+        │   │     │     │    └ {}
+        │   │     │     └ 3
+        │   │     └ 2
+        │   └ 1
+        └ <function foo at 0xDEADBEEF>
+
+ZeroDivisionError: division by zero

tests/exceptions/output/modern/type_hints.txt

@@ -0,0 +1,22 @@
+
+Traceback (most recent call last):
+
+  File "tests/exceptions/source/modern/type_hints.py", line 23, in <module>
+    main()
+    └ <function main at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/type_hints.py", line 19, in main
+    bar: Name = foo(1, 2, 3)
+                └ <function foo at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/type_hints.py", line 15, in foo
+    def foo(a: int, b: Union[Name, float], c: "Name") -> T: 1 / 0
+        │   │       │  │     │             │             └ ~T
+        │   │       │  │     │             └ 3
+        │   │       │  │     └ <class 'str'>
+        │   │       │  └ typing.Union
+        │   │       └ 2
+        │   └ 1
+        └ <function foo at 0xDEADBEEF>
+
+ZeroDivisionError: division by zero

tests/exceptions/output/modern/walrus_operator.txt

@@ -0,0 +1,16 @@
+
+Traceback (most recent call last):
+
+> File "tests/exceptions/source/modern/walrus_operator.py", line 25, in <module>
+    main()
+    └ <function main at 0xDEADBEEF>
+
+  File "tests/exceptions/source/modern/walrus_operator.py", line 19, in main
+    (walrus := foo())
+     │         └ <function foo at 0xDEADBEEF>
+     └ False
+
+  File "tests/exceptions/source/modern/walrus_operator.py", line 8, in foo
+    if a := "a" + (x:=1/0):
+
+ZeroDivisionError: division by zero

tests/exceptions/source/modern/exception_group_catch.py

@@ -0,0 +1,25 @@
+# fmt: off
+import sys
+
+from loguru import logger
+
+logger.remove()
+logger.add(sys.stderr, format="", colorize=True, backtrace=False, diagnose=True)
+
+x = ValueError
+
+
+def a():
+    try:
+        raise ExceptionGroup("group", [ValueError(1)])
+    except* x as e: raise ValueError(2)
+
+
+def b():
+    try:
+        raise ExceptionGroup("group", [TypeError(1)])
+    except* TypeError: a()
+
+
+with logger.catch():
+    b()

tests/exceptions/source/modern/f_string.py

@@ -0,0 +1,17 @@
+# fmt: off
+import sys
+
+from loguru import logger
+
+logger.remove()
+logger.add(sys.stderr, format="", colorize=True, backtrace=False, diagnose=True)
+
+
+def hello():
+    name = "world"
+    f = 1
+    f"{name}" and f'{{ {f / 0} }}'
+
+
+with logger.catch():
+    hello()

tests/exceptions/source/modern/match_statement.py

@@ -0,0 +1,21 @@
+# fmt: off
+import sys
+
+from loguru import logger
+
+logger.remove()
+logger.add(sys.stderr, format="", colorize=True, backtrace=False, diagnose=True)
+
+def case(x):
+    y = 1
+    match y / 0:
+        case 1:
+            pass
+
+def match(x):
+    y = 1
+    match x:
+        case y: case(x)
+
+with logger.catch():
+    match(1)

tests/exceptions/source/modern/positional_only_argument.py

@@ -0,0 +1,23 @@
+# fmt: off
+import sys
+from typing import TypeVar, Union
+
+from loguru import logger
+
+logger.remove()
+logger.add(sys.stderr, format="", colorize=True, backtrace=False, diagnose=True)
+
+
+T = TypeVar("T")
+Name = str
+
+
+def foo(a, /, b, *, c, **d): 1 / 0
+
+
+def main():
+    foo(1, 2, c=3)
+
+
+with logger.catch():
+    main()

tests/exceptions/source/modern/type_hints.py

@@ -0,0 +1,23 @@
+# fmt: off
+import sys
+from typing import TypeVar, Union
+
+from loguru import logger
+
+logger.remove()
+logger.add(sys.stderr, format="", colorize=True, backtrace=False, diagnose=True)
+
+
+T = TypeVar("T")
+Name = str
+
+
+def foo(a: int, b: Union[Name, float], c: "Name") -> T: 1 / 0
+
+
+def main():
+    bar: Name = foo(1, 2, 3)
+
+
+with logger.catch():
+    main()

tests/exceptions/source/modern/walrus_operator.py

@@ -0,0 +1,25 @@
+# fmt: off
+import sys
+
+from loguru import logger
+
+
+def foo():
+    if a := "a" + (x:=1/0):
+        pass
+
+
+def bar():
+    return [y for x in [1, 2] if (y := foo()) != 0]
+
+
+@logger.catch
+def main():
+    walrus = False
+    (walrus := foo())
+
+
+logger.remove()
+logger.add(sys.stderr, format="", diagnose=True, backtrace=True, colorize=True)
+
+main()

tests/test_exceptions_formatting.py

@@ -229,6 +229,12 @@ def test_exception_others(filename):
 @pytest.mark.parametrize(
     "filename, minimum_python_version",
     [
+        ("type_hints", (3, 6)),
+        ("f_string", (3, 6)),
+        ("positional_only_argument", (3, 8)),
+        ("walrus_operator", (3, 8)),
+        ("match_statement", (3, 10)),
+        ("exception_group_catch", (3, 11)),
         ("grouped_simple", (3, 11)),
         ("grouped_nested", (3, 11)),
         ("grouped_with_cause_and_context", (3, 11)),