Improve of the test output for logical expression with brackets.

  Fixes pytest-dev#925

CHANGELOG.rst

@@ -36,7 +36,9 @@
   Thanks `@bagerard`_ for reporting (`#1503`_). Thanks to `@davehunt`_ and
   `@tomviner`_ for PR.
 
-*
+* Improve of the test output for logical expression with brackets.
+  Fixes(`#925`_). Thanks `@DRMacIver`_ for reporting. Thanks to `@RedBeardCode`_
+  for PR.
 
 *
 
@@ -47,6 +49,7 @@
 .. _#1553: https://github.com/pytest-dev/pytest/issues/1553
 .. _#1626: https://github.com/pytest-dev/pytest/pull/1626
 .. _#1503: https://github.com/pytest-dev/pytest/issues/1503
+.. _#925: https://github.com/pytest-dev/pytest/issues/925
 
 .. _@graingert: https://github.com/graingert
 .. _@taschini: https://github.com/taschini
@@ -55,6 +58,7 @@
 .. _@Vogtinator: https://github.com/Vogtinator
 .. _@bagerard: https://github.com/bagerard
 .. _@davehunt: https://github.com/davehunt
+.. _@DRMacIver: https://github.com/DRMacIver
 
 
 2.9.2

_pytest/assertion/rewrite.py

@@ -1,6 +1,7 @@
 """Rewrite assertion AST to produce nice error messages"""
 
 import ast
+import _ast
 import errno
 import itertools
 import imp
@@ -753,6 +754,8 @@ def visit_BoolOp(self, boolop):
         self.statements = save
         self.on_failure = fail_save
         expl_template = self.helper("format_boolop", expl_list, ast.Num(is_or))
+        #if isinstance(boolop, (_ast.Compare, _ast.BoolOp)):
+        #    expl_template = "({0})".format(expl_template)
         expl = self.pop_format_context(expl_template)
         return ast.Name(res_var, ast.Load()), self.explanation_param(expl)
 
@@ -855,6 +858,8 @@ def visit_Attribute(self, attr):
     def visit_Compare(self, comp):
         self.push_format_context()
         left_res, left_expl = self.visit(comp.left)
+        if isinstance(comp.left, (_ast.Compare, _ast.BoolOp)):
+            left_expl = "({0})".format(left_expl)
         res_variables = [self.variable() for i in range(len(comp.ops))]
         load_names = [ast.Name(v, ast.Load()) for v in res_variables]
         store_names = [ast.Name(v, ast.Store()) for v in res_variables]
@@ -864,6 +869,8 @@ def visit_Compare(self, comp):
         results = [left_res]
         for i, op, next_operand in it:
             next_res, next_expl = self.visit(next_operand)
+            if isinstance(next_operand, (_ast.Compare, _ast.BoolOp)):
+                next_expl = "({0})".format(next_expl)
             results.append(next_res)
             sym = binop_map[op.__class__]
             syms.append(ast.Str(sym))

testing/test_assertrewrite.py

@@ -720,3 +720,30 @@ def test_long_repr():
     """)
     result = testdir.runpytest()
     assert 'unbalanced braces' not in result.stdout.str()
+
+
+class TestIssue925():
+    def test_simple_case(self, testdir):
+        testdir.makepyfile("""
+        def test_ternary_display():
+            assert (False == False) == False
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines('*E*assert (False == False) == False')
+
+    def test_long_case(self, testdir):
+        testdir.makepyfile("""
+        def test_ternary_display():
+             assert False == (False == True) == True
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines('*E*assert (False == True) == True')
+
+    def test_many_brackets(self, testdir):
+        testdir.makepyfile("""
+            def test_ternary_display():
+                 assert True == ((False == True) == True)
+            """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines('*E*assert True == ((False == True) == True)')
+