Adds TYPER_STANDARD_TRACEBACK variable

Keeps support fo `_TYPER_STANDARD_TRACEBACK` but notes as deprecated
because:
- It is non-standard for an advertised env to start with an underscore.
- Environment variables that start with an underscore have been observed as
  causing issues in some execution environments (e.g. with AWS Lambda).

See: #1284

Author: colin-nolan

docs/tutorial/exceptions.md

@@ -235,14 +235,14 @@ TypeError: can only concatenate str (not "int") to str
 
 </div>
 
-You could also achieve the same with the environment variable `_TYPER_STANDARD_TRACEBACK=1`.
+You could also achieve the same with the environment variable `TYPER_STANDARD_TRACEBACK=1` (or by setting the deprecated variable `_TYPER_STANDARD_TRACEBACK=1`).
 
 This will work for any other Typer program too, in case you need to debug a problem in a Typer program made by someone else:
 
 <div class="termy">
 
 ```console
-export _TYPER_STANDARD_TRACEBACK=1
+export TYPER_STANDARD_TRACEBACK=1
 $ python main.py
 
 

tests/test_tracebacks.py

@@ -10,7 +10,11 @@ def test_traceback_no_rich():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" not in result.stderr
 
@@ -25,7 +29,11 @@ def test_traceback_no_rich_short_disable():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" not in result.stderr
 
@@ -40,7 +48,11 @@ def test_unmodified_traceback():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "morty" in result.stdout, "the call to the first app should work normally"
     assert "return callback(**use_params)" in result.stderr, (

tests/test_tutorial/test_exceptions/test_tutorial001.py

@@ -16,7 +16,11 @@ def test_traceback_rich():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" not in result.stderr
 
@@ -32,7 +36,7 @@ def test_standard_traceback_env_var():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": "1"},
+        env={**os.environ, "TYPER_STANDARD_TRACEBACK": "1"},
     )
     assert "return get_command(self)(*args, **kwargs)" in result.stderr
 

tests/test_tutorial/test_exceptions/test_tutorial002.py

@@ -16,7 +16,11 @@ def test_traceback_rich():
         [sys.executable, "-m", "coverage", "run", str(file_path), "secret"],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" not in result.stderr
 
@@ -32,7 +36,7 @@ def test_standard_traceback_env_var():
         [sys.executable, "-m", "coverage", "run", str(file_path), "secret"],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": "1"},
+        env={**os.environ, "TYPER_STANDARD_TRACEBACK": "1"},
     )
     assert "return get_command(self)(*args, **kwargs)" in result.stderr
 

tests/test_tutorial/test_exceptions/test_tutorial003.py

@@ -16,7 +16,11 @@ def test_traceback_rich_pretty_short_disable():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" not in result.stderr
 

tests/test_tutorial/test_exceptions/test_tutorial004.py

@@ -16,7 +16,11 @@ def test_rich_pretty_exceptions_disable():
         [sys.executable, "-m", "coverage", "run", str(file_path)],
         capture_output=True,
         encoding="utf-8",
-        env={**os.environ, "_TYPER_STANDARD_TRACEBACK": ""},
+        env={
+            **os.environ,
+            "TYPER_STANDARD_TRACEBACK": "",
+            "_TYPER_STANDARD_TRACEBACK": "",
+        },
     )
     assert "return get_command(self)(*args, **kwargs)" in result.stderr
 

typer/main.py

@@ -65,7 +65,9 @@ def except_hook(
     exception_config: Union[DeveloperExceptionConfig, None] = getattr(
         exc_value, _typer_developer_exception_attr_name, None
     )
-    standard_traceback = os.getenv("_TYPER_STANDARD_TRACEBACK")
+    standard_traceback = os.getenv(
+        "TYPER_STANDARD_TRACEBACK", os.getenv("_TYPER_STANDARD_TRACEBACK")
+    )
     if (
         standard_traceback
         or not exception_config