OpenHome/venv/Lib/site-packages/_pytest/assertion/truncate.py
2021-07-21 21:33:05 +02:00

101 lines
3.4 KiB
Python

"""Utilities for truncating assertion output.
Current default behaviour is to truncate assertion explanations at
~8 terminal lines, unless running in "-vv" mode or running on CI.
"""
import os
from typing import List
from typing import Optional
from _pytest.nodes import Item
DEFAULT_MAX_LINES = 8
DEFAULT_MAX_CHARS = 8 * 80
USAGE_MSG = "use '-vv' to show"
def truncate_if_required(
explanation: List[str], item: Item, max_length: Optional[int] = None
) -> List[str]:
"""Truncate this assertion explanation if the given test item is eligible."""
if _should_truncate_item(item):
return _truncate_explanation(explanation)
return explanation
def _should_truncate_item(item: Item) -> bool:
"""Whether or not this test item is eligible for truncation."""
verbose = item.config.option.verbose
return verbose < 2 and not _running_on_ci()
def _running_on_ci() -> bool:
"""Check if we're currently running on a CI system."""
env_vars = ["CI", "BUILD_NUMBER"]
return any(var in os.environ for var in env_vars)
def _truncate_explanation(
input_lines: List[str],
max_lines: Optional[int] = None,
max_chars: Optional[int] = None,
) -> List[str]:
"""Truncate given list of strings that makes up the assertion explanation.
Truncates to either 8 lines, or 640 characters - whichever the input reaches
first. The remaining lines will be replaced by a usage message.
"""
if max_lines is None:
max_lines = DEFAULT_MAX_LINES
if max_chars is None:
max_chars = DEFAULT_MAX_CHARS
# Check if truncation required
input_char_count = len("".join(input_lines))
if len(input_lines) <= max_lines and input_char_count <= max_chars:
return input_lines
# Truncate first to max_lines, and then truncate to max_chars if max_chars
# is exceeded.
truncated_explanation = input_lines[:max_lines]
truncated_explanation = _truncate_by_char_count(truncated_explanation, max_chars)
# Add ellipsis to final line
truncated_explanation[-1] = truncated_explanation[-1] + "..."
# Append useful message to explanation
truncated_line_count = len(input_lines) - len(truncated_explanation)
truncated_line_count += 1 # Account for the part-truncated final line
msg = "...Full output truncated"
if truncated_line_count == 1:
msg += f" ({truncated_line_count} line hidden)"
else:
msg += f" ({truncated_line_count} lines hidden)"
msg += f", {USAGE_MSG}"
truncated_explanation.extend(["", str(msg)])
return truncated_explanation
def _truncate_by_char_count(input_lines: List[str], max_chars: int) -> List[str]:
# Check if truncation required
if len("".join(input_lines)) <= max_chars:
return input_lines
# Find point at which input length exceeds total allowed length
iterated_char_count = 0
for iterated_index, input_line in enumerate(input_lines):
if iterated_char_count + len(input_line) > max_chars:
break
iterated_char_count += len(input_line)
# Create truncated explanation with modified final line
truncated_result = input_lines[:iterated_index]
final_line = input_lines[iterated_index]
if final_line:
final_line_truncate_point = max_chars - iterated_char_count
final_line = final_line[:final_line_truncate_point]
truncated_result.append(final_line)
return truncated_result