TST: Add tests for build_err_msg

1 files changed, 43 insertions, 0 deletions

diff --git a/numpy/testing/tests/test_utils.py b/numpy/testing/tests/test_utils.py
index 5956a4294..3c66c3cb3 100644
--- a/numpy/testing/tests/test_utils.py
+++ b/numpy/testing/tests/test_utils.py
@@ -134,6 +134,49 @@ class TestArrayEqual(_GenericTest, unittest.TestCase):
 
         self._test_not_equal(c, b)
 
+class TestBuildErrorMessage(unittest.TestCase):
+    def test_build_err_msg_defaults(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg)
+        b = ('\nItems are not equal: There is a mismatch\n ACTUAL: array([ '
+             '1.00001,  2.00002,  3.00003])\n DESIRED: array([ 1.00002,  '
+             '2.00003,  3.00004])')
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_no_verbose(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, verbose=False)
+        b = '\nItems are not equal: There is a mismatch'
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_custom_names(self):
+        x = np.array([1.00001, 2.00002, 3.00003])
+        y = np.array([1.00002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, names=('FOO', 'BAR'))
+        b = ('\nItems are not equal: There is a mismatch\n FOO: array([ '
+             '1.00001,  2.00002,  3.00003])\n BAR: array([ 1.00002,  2.00003,  '
+             '3.00004])')
+        self.assertEqual(a, b)
+
+    def test_build_err_msg_custom_precision(self):
+        x = np.array([1.000000001, 2.00002, 3.00003])
+        y = np.array([1.000000002, 2.00003, 3.00004])
+        err_msg = 'There is a mismatch'
+
+        a = build_err_msg([x, y], err_msg, precision=10)
+        b = ('\nItems are not equal: There is a mismatch\n ACTUAL: array([ '
+             '1.000000001,  2.00002    ,  3.00003    ])\n DESIRED: array([ '
+             '1.000000002,  2.00003    ,  3.00004    ])')
+        self.assertEqual(a, b)
+
 class TestEqual(TestArrayEqual):
     def setUp(self):
         self._assert_func = assert_equal