From 6e8f6f91cbe0c40ca72efecaed95912beb23548d Mon Sep 17 00:00:00 2001
From: Imanol <imanflow@gmail.com>
Date: Thu, 25 Feb 2021 23:51:52 +0100
Subject: [PATCH] TST: expand assert messages in assert_geoseries_equal (#1808)

* expanded assert messages. Refactor of duplicated code

* black formatted

* fix forgotten if

* fix forgotten ifs

* reformat code, add indeces to error and full first geometries

* fix typo

* expand tests and check for error message

* truncate string

Co-authored-by: ImanolUr <imanol@live-eo.com>
Co-authored-by: Martin Fleischmann <martin@martinfleischmann.net>
Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>
---
 geopandas/testing.py            | 64 ++++++++++++++++++++++++++-------
 geopandas/tests/test_testing.py | 17 ++++++++-
 2 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/geopandas/testing.py b/geopandas/testing.py
index 437af0d..7e0daa7 100644
--- a/geopandas/testing.py
+++ b/geopandas/testing.py
@@ -133,15 +133,58 @@ def assert_geoseries_equal(
     if not check_crs:
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "CRS mismatch", UserWarning)
-            if check_less_precise:
-                assert geom_almost_equals(left, right)
-            else:
-                assert geom_equals(left, right)
+            _check_equality(left, right, check_less_precise)
     else:
-        if check_less_precise:
-            assert geom_almost_equals(left, right)
-        else:
-            assert geom_equals(left, right)
+        _check_equality(left, right, check_less_precise)
+
+
+def _truncated_string(geom):
+    """Truncated WKT repr of geom"""
+    s = str(geom)
+    if len(s) > 100:
+        return s[:100] + "..."
+    else:
+        return s
+
+
+def _check_equality(left, right, check_less_precise):
+    assert_error_message = (
+        "{0} out of {1} geometries are not {3}equal.\n"
+        "Indices where geometries are not {3}equal: {2} \n"
+        "The first not {3}equal geometry:\n"
+        "Left: {4}\n"
+        "Right: {5}\n"
+    )
+    if check_less_precise:
+        precise = "almost "
+        if not geom_almost_equals(left, right):
+            unequal_left_geoms = left[~left.geom_almost_equals(right)]
+            unequal_right_geoms = right[~left.geom_almost_equals(right)]
+            raise AssertionError(
+                assert_error_message.format(
+                    len(unequal_left_geoms),
+                    len(left),
+                    unequal_left_geoms.index.to_list(),
+                    precise,
+                    _truncated_string(unequal_left_geoms.iloc[0]),
+                    _truncated_string(unequal_right_geoms.iloc[0]),
+                )
+            )
+    else:
+        precise = ""
+        if not geom_equals(left, right):
+            unequal_left_geoms = left[~left.geom_almost_equals(right)]
+            unequal_right_geoms = right[~left.geom_almost_equals(right)]
+            raise AssertionError(
+                assert_error_message.format(
+                    len(unequal_left_geoms),
+                    len(left),
+                    unequal_left_geoms.index.to_list(),
+                    precise,
+                    _truncated_string(unequal_left_geoms.iloc[0]),
+                    _truncated_string(unequal_right_geoms.iloc[0]),
+                )
+            )
 
 
 def assert_geodataframe_equal(
@@ -212,10 +255,7 @@ def assert_geodataframe_equal(
         "GeoDataFrame shape mismatch, left: {lshape!r}, right: {rshape!r}.\n"
         "Left columns: {lcols!r}, right columns: {rcols!r}"
     ).format(
-        lshape=left.shape,
-        rshape=right.shape,
-        lcols=left.columns,
-        rcols=right.columns,
+        lshape=left.shape, rshape=right.shape, lcols=left.columns, rcols=right.columns
     )
 
     if check_like:
diff --git a/geopandas/tests/test_testing.py b/geopandas/tests/test_testing.py
index 582c01b..e3cec21 100644
--- a/geopandas/tests/test_testing.py
+++ b/geopandas/tests/test_testing.py
@@ -46,6 +46,14 @@ s4 = s1.copy()
 s4.crs = 4326
 s5 = s2.copy()
 s5.crs = 27700
+
+s6 = GeoSeries(
+    [
+        Polygon([(0, 3), (0, 0), (2, 0), (2, 2)]),
+        Polygon([(2, 2), (4, 2), (4, 4), (2, 4)]),
+    ]
+)
+
 df4 = GeoDataFrame(
     {"col1": [1, 2], "geometry": s1.copy(), "geom2": s4.copy(), "geom3": s5.copy()},
     crs=3857,
@@ -63,8 +71,15 @@ def test_geoseries():
     assert_geoseries_equal(s3, s2, check_series_type=False, check_dtype=False)
     assert_geoseries_equal(s1, s4, check_series_type=False)
 
-    with pytest.raises(AssertionError):
+    with pytest.raises(AssertionError) as error:
         assert_geoseries_equal(s1, s2, check_less_precise=True)
+    assert "1 out of 2 geometries are not almost equal" in str(error.value)
+    assert "not almost equal: [0]" in str(error.value)
+
+    with pytest.raises(AssertionError) as error:
+        assert_geoseries_equal(s2, s6, check_less_precise=False)
+    assert "1 out of 2 geometries are not equal" in str(error.value)
+    assert "not equal: [0]" in str(error.value)
 
 
 def test_geodataframe():