如何在Python中隔离ANTLR解析器的测试用例？
如何在Python中隔离ANTLR解析器的测试用例？
提问于 2021-03-16 20:02:32
我想使用Python和ANTLR v4运行时通过一些测试用例来测试我的antlr解析器。我遇到的问题是关于测试用例的隔离。在每个测试用例中，都应该解析另一个文件。但是解析器(或者流阅读器--我不知道)似乎连接了到目前为止读取的文件。因此，在测试用例n中，解析结果是case n-1和case n的结果的连接(并递归返回到第一个测试用例)。
下面是一个最小的工作示例：
文件Minimal.g4
grammar Minimal ;
WS : [ \t\n\r\f] ;
WORD : (~ ([ \n\r\t\f]) )+ ;
text : ( token | WS+ )* ;
token : WORD ;文件minimal/minimal.py
from antlr4 import *
from minimal.MinimalListener import MinimalListener
class MinimalListListener(MinimalListener):
tokens = []
def exitToken(self, ctx):
self.tokens.append(ctx.WORD().getText())文件test_minimal.py
import unittest
import os
from antlr4 import *
from minimal.MinimalListener import MinimalListener
from minimal.MinimalLexer import MinimalLexer
from minimal.MinimalParser import MinimalParser
from minimal.minimal import MinimalListListener
class MinimalTstBase(unittest.TestCase):
fname = None
def setUp(self):
self.parsed = []
input_stream = FileStream(os.path.join("samples", self.fname), encoding="utf-8")
lexer = MinimalLexer(input_stream)
stream = CommonTokenStream(lexer)
parser = MinimalParser(stream)
tree = parser.text() # start rule
printer = MinimalListListener()
walker = ParseTreeWalker()
walker.walk(printer, tree)
self.parsed = printer.tokens # get result stored in the listener
def tearDown(self):
self.parsed = []
class TestCite1(MinimalTstBase):
fname = "cite1.txt"
def test_parsed(self):
self.assertEqual(
self.parsed,
["A", "B"])
class TestCite2(MinimalTstBase):
fname = "cite2.txt"
def test_parsed(self):
self.assertEqual(
self.parsed,
['c', 'd'])文件samples/cite1.txt
A B文件samples/cite2.txt
c d文件minimal/__init__.py只是一个空文件。文件setup.py只是样板文件：
from setuptools import find_packages, setup
setup(
name = "minimal-antlr-testing-example",
version = "0.0.1",
description = "Minimal testing example",
classifiers = [
"Programming Language :: Python :: 3",
"License :: OSI Approved :: MIT License",
"Operating System :: OS Independent",
],
packages = find_packages(where="."),
python_requires = ">=3.6",
install_requires = [
"wheel",
"setuptools",
"antlr4-python3-runtime==4.9.1"
],
test_suite = 'minimal',
)文件requirements.txt
wheel==0.36.2
antlr4-python3-runtime==4.9.1运行后
java -cp antlr-4.9.1-complete.jar org.antlr.v4.Tool -o minimal/ \
-Xexact-output-dir -Dlanguage="Python3" Minimal.g4有以下文件：
./minimal/Minimal.tokens
./minimal/MinimalListener.py
./minimal/MinimalParser.py
./minimal/Minimal.interp
./minimal/MinimalLexer.tokens
./minimal/MinimalLexer.py
./minimal/MinimalLexer.interp
./minimal/test_minimal.py
./minimal/minimal.py
./minimal/__init__.py
./samples/cite2.txt
./samples/cite1.txt
./Minimal.g4
./requirements.txt
./setup.py安装并运行测试：
python3 -m venv env
source env/bin/activate
python -m pip install -r requirements.txt
python setup.py bdist_wheel
python setup.py test
...
test_parsed (minimal.test_minimal.TestCite1) ... ok
test_parsed (minimal.test_minimal.TestCite2) ... FAIL
======================================================================
FAIL: test_parsed (minimal.test_minimal.TestCite2)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/clueck/src/minimal/antlr/minimal/test_minimal.py", line 46, in test_parsed
['c', 'd'])
AssertionError: Lists differ: ['A', 'B', 'c', 'd'] != ['c', 'd']
First differing element 0:
'A'
'c'
First list contains 2 additional elements.
First extra element 2:
'c'
- ['A', 'B', 'c', 'd']
+ ['c', 'd']如何在运行单元测试时隔离解析器运行？
亲切的问候
回答 1
Stack Overflow用户
回答已采纳
发布于 2021-03-17 03:39:36
class MinimalListListener(MinimalListener):
tokens = []这将创建一个属于MinimalListListener类的列表，该列表在该类的所有实例之间共享。因此，如果创建类的两个实例，这两个实例都将元素添加到列表中，则列表最终将包含来自这两个实例的元素。
要在Python中创建特定于每个实例的变量，请在__init__中设置变量，而不是设置类体：
class MinimalListListener(MinimalListener):
def __init__(self):
self.tokens = []页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/66654856
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