[raise-missing-from] Clearer message and example in the documentation

Co-authored-by: cool-RR <ram@rachum.com>

Refs #5953
Closes #3707

Author: Pierre-Sassoulas

doc/data/messages/r/raise-missing-from/bad.py

@@ -0,0 +1,4 @@
+try:
+    1 / 0
+except ZeroDivisionError as e:
+    raise ValueError("Rectangle Area cannot be zero")  # [raise-missing-from]

doc/data/messages/r/raise-missing-from/details.rst

@@ -0,0 +1,4 @@
+You are raising the %s exception after the %s exception was caught.
+It's likely that the second exception is a friendly re-wrapping of the first exception,
+therefore you should use ``raise new_exception from old_exception`` to see an accurate message
+between the two tracebacks.

doc/data/messages/r/raise-missing-from/good.py

@@ -0,0 +1,4 @@
+try:
+    1 / 0
+except ZeroDivisionError as e:
+    raise ValueError("Rectangle Area cannot be zero") from e

doc/data/messages/r/raise-missing-from/related.rst

@@ -0,0 +1 @@
+- `PEP 3132 <https://www.python.org/dev/peps/pep-3132/>`_

pylint/checkers/exceptions.py

@@ -131,7 +131,7 @@ def _is_raising(body: list) -> bool:
         "try-except-raise block!",
     ),
     "W0707": (
-        "Consider explicitly re-raising using the 'from' keyword",
+        "Consider explicitly re-raising using 'raise NewError(...) from old_error'",
         "raise-missing-from",
         "Python 3's exception chaining means it shows the traceback of the "
         "current exception, but also the original exception. Not using `raise "

tests/functional/r/raise_missing_from.txt

@@ -1,7 +1,7 @@
-raise-missing-from:11:4:11:18::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:19:4:19:25::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:25:4:25:18::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:31:4:31:18::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:45:20:45:34::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:53:4:53:20::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
-raise-missing-from:59:4:59:47::Consider explicitly re-raising using the 'from' keyword:UNDEFINED
+raise-missing-from:11:4:11:18::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:19:4:19:25::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:25:4:25:18::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:31:4:31:18::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:45:20:45:34::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:53:4:53:20::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED
+raise-missing-from:59:4:59:47::Consider explicitly re-raising using 'raise NewError(...) from old_error':UNDEFINED