fix import of pyparsing from simple_unit_tests.py

1 files changed, 160 insertions, 0 deletions

diff --git a/simple_unit_tests.py b/simple_unit_tests.py
new file mode 100644
index 0000000..d2795b5
--- /dev/null
+++ b/simple_unit_tests.py
@@ -0,0 +1,160 @@
+#
+# simple_unit_tests.py
+#
+# While these unit tests *do* perform low-level unit testing of the classes in pyparsing,
+# this testing module should also serve an instructional purpose, to clearly show simple passing
+# and failing parse cases of some basic pyparsing expressions.
+#
+# Copyright (c) 2018  Paul T. McGuire
+#
+
+import unittest
+import pyparsing as pp
+from collections import namedtuple
+
+# Test spec data class for specifying simple pyparsing test cases
+PpTestSpec = namedtuple("PpTestSpec", "desc expr text expected_list expected_dict expected_fail_locn")
+PpTestSpec.__new__.__defaults__ = ('', pp.Empty(), '', None, None, None)
+
+
+class PyparsingExpressionTestCase(unittest.TestCase):
+    """
+    Base pyparsing testing class to parse various pyparsing expressions against
+    given text strings. Subclasses must define a class attribute 'tests' which
+    is a list of PpTestSpec instances.
+    """
+    def test_match(self):
+        if self.__class__ is PyparsingExpressionTestCase:
+            return
+
+        for test_spec in self.tests:
+            # for each spec in the class's tests list, create a subtest
+            # that will either:
+            #  - parse the string with expected success, display the 
+            #    results, and validate the returned ParseResults
+            #  - or parse the string with expected failure, display the 
+            #    error message and mark the error location, and validate
+            #    the location against an expected value
+            with self.subTest(test_spec=test_spec):
+                test_spec.expr.streamline()
+                print("\n{} - {}({})".format(test_spec.desc, 
+                                             type(test_spec.expr).__name__, 
+                                             test_spec.expr))
+
+                if test_spec.expected_fail_locn is None:
+                    # expect success
+                    result = test_spec.expr.parseString(test_spec.text)
+                    print(result.dump())
+                    # compare results against given list and/or dict
+                    if test_spec.expected_list is not None:
+                        self.assertEqual(result.asList(), test_spec.expected_list)
+                    if test_spec.expected_dict is not None:
+                        self.assertEqual(result.asDict(), test_spec.expected_dict)
+
+                else:
+                    # expect fail
+                    with self.assertRaises(pp.ParseException) as ar:
+                        test_spec.expr.parseString(test_spec.text)
+                    print(' ', test_spec.text or "''")
+                    print(' ', ' '*ar.exception.loc+'^')
+                    print(' ', ar.exception.msg)
+                    self.assertEqual(ar.exception.loc, test_spec.expected_fail_locn)
+
+
+
+class TestLiteral(PyparsingExpressionTestCase):
+    tests = [
+        PpTestSpec(
+            desc = "Simple match",
+            expr = pp.Literal("xyz"),
+            text = "xyz",
+            expected_list = ["xyz"],
+        ),
+        PpTestSpec(
+            desc = "Simple match after skipping whitespace",
+            expr = pp.Literal("xyz"),
+            text = "  xyz",
+            expected_list = ["xyz"],
+        ),
+        PpTestSpec(
+            desc = "Simple fail - parse an empty string",
+            expr = pp.Literal("xyz"),
+            text = "",
+            expected_fail_locn = 0,
+        ),
+        PpTestSpec(
+            desc = "Simple fail - parse a mismatching string",
+            expr = pp.Literal("xyz"),
+            text = "xyu",
+            expected_fail_locn = 0,
+        ),
+        PpTestSpec(
+            desc = "Simple fail - parse a partially matching string",
+            expr = pp.Literal("xyz"),
+            text = "xy",
+            expected_fail_locn = 0,
+        ),
+        PpTestSpec(
+            desc = "Fail - parse a partially matching string by matching individual letters",
+            expr =  pp.Literal("x") + pp.Literal("y") + pp.Literal("z"),
+            text = "xy",
+            expected_fail_locn = 2,
+        ),
+    ]
+
+
+class TestWord(PyparsingExpressionTestCase):
+    tests = [
+        PpTestSpec(
+            desc = "Simple Word match",
+            expr = pp.Word("xy"),
+            text = "xxyxxyy",
+            expected_list = ["xxyxxyy"],
+        ),
+        PpTestSpec(
+            desc = "Simple Word match of two separate Words",
+            expr = pp.Word("x") + pp.Word("y"),
+            text = "xxxxxyy",
+            expected_list = ["xxxxx", "yy"],
+        ),
+        PpTestSpec(
+            desc = "Simple Word match of two separate Words - implicitly skips whitespace",
+            expr = pp.Word("x") + pp.Word("y"),
+            text = "xxxxx yy",
+            expected_list = ["xxxxx", "yy"],
+        ),
+    ]
+
+
+class TestResultsName(PyparsingExpressionTestCase):
+    tests = [
+        PpTestSpec(
+            desc = "Match with results name",
+            expr = pp.Literal("xyz").setResultsName("value"),
+            text = "xyz",
+            expected_dict = {'value': 'xyz'},
+            expected_list = ['xyz'],
+        ),
+        PpTestSpec(
+            desc = "Match with results name - using naming short-cut",
+            expr = pp.Literal("xyz")("value"),
+            text = "xyz",
+            expected_dict = {'value': 'xyz'},
+            expected_list = ['xyz'],
+        ),
+    ]
+
+
+class TestParseAction(PyparsingExpressionTestCase):
+    tests = [
+        PpTestSpec(
+            desc = "Match with numeric string converted to int",
+            expr = pp.Word("0123456789").addParseAction(lambda t: int(t[0])),
+            text = "12345",
+            expected_list = [12345],  # note - result is type int, not str 
+        ),
+    ]
+    
+
+if __name__ == '__main__':
+    unittest.main()
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