Merge pull request #1118 from effigies/test/numpy_1.24-dev

TEST: Suppress new numpy warning on nan-to-int cast

numpy/numpy#21437 does not require us to change our behavior, but does require us to change our expectations of what warnings are raised. Since this is quite an edge case, it seems to make more sense to suppress the warning and eventually expect it when numpy 1.24 becomes our minimum.

Author: matthew-brett

nibabel/tests/test_volumeutils.py

@@ -20,6 +20,7 @@
 import bz2
 import threading
 import time
+from packaging.version import Version
 
 import numpy as np
 
@@ -68,6 +69,8 @@
 IUINT_TYPES = INT_TYPES + np.sctypes['uint']
 NUMERIC_TYPES = CFLOAT_TYPES + IUINT_TYPES
 
+FP_RUNTIME_WARN = Version(np.__version__) >= Version('1.24.0.dev0+239')
+
 
 def test__is_compressed_fobj():
     # _is_compressed helper function
@@ -413,7 +416,7 @@ def test_a2f_nan2zero():
     # How weird?  Look at arr.astype(np.int64)
     with np.errstate(invalid='ignore'):
         data_back = write_return(arr, str_io, np.int64, nan2zero=False)
-    assert_array_equal(data_back, arr.astype(np.int64))
+        assert_array_equal(data_back, arr.astype(np.int64))
 
 
 def test_a2f_nan2zero_scaling():
@@ -672,40 +675,43 @@ def test_a2f_nan2zero_range():
         arr = np.array([-1, 0, 1, np.nan], dtype=dt)
         # Error occurs for arrays without nans too
         arr_no_nan = np.array([-1, 0, 1, 2], dtype=dt)
-        warn_type = np.ComplexWarning if np.issubdtype(dt, np.complexfloating) else None
+        complex_warn = (np.ComplexWarning,) if np.issubdtype(dt, np.complexfloating) else ()
+        # Casting nan to int will produce a RuntimeWarning in numpy 1.24
+        nan_warn = (RuntimeWarning,) if FP_RUNTIME_WARN else ()
+        c_and_n_warn = complex_warn + nan_warn
         # No errors from explicit thresholding
         # mn thresholding excluding zero
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(complex_warn) if complex_warn else error_warnings():
             assert_array_equal([1, 1, 1, 0],
                                write_return(arr, fobj, np.int8, mn=1))
         # mx thresholding excluding zero
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(complex_warn) if complex_warn else error_warnings():
             assert_array_equal([-1, -1, -1, 0],
                                write_return(arr, fobj, np.int8, mx=-1))
         # Errors from datatype threshold after scaling
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(complex_warn) if complex_warn else error_warnings():
             back_arr = write_return(arr, fobj, np.int8, intercept=128)
         assert_array_equal([-128, -128, -127, -128], back_arr)
         with pytest.raises(ValueError):
             write_return(arr, fobj, np.int8, intercept=129)
         with pytest.raises(ValueError):
             write_return(arr_no_nan, fobj, np.int8, intercept=129)
         # OK with nan2zero false, but we get whatever nan casts to
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(c_and_n_warn) if c_and_n_warn else error_warnings():
             nan_cast = np.array(np.nan, dtype=dt).astype(np.int8)
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(c_and_n_warn) if c_and_n_warn else error_warnings():
             back_arr = write_return(arr, fobj, np.int8, intercept=129, nan2zero=False)
         assert_array_equal([-128, -128, -128, nan_cast], back_arr)
         # divslope
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(complex_warn) if complex_warn else error_warnings():
             back_arr = write_return(arr, fobj, np.int8, intercept=256, divslope=2)
         assert_array_equal([-128, -128, -128, -128], back_arr)
         with pytest.raises(ValueError):
             write_return(arr, fobj, np.int8, intercept=257.1, divslope=2)
         with pytest.raises(ValueError):
             write_return(arr_no_nan, fobj, np.int8, intercept=257.1, divslope=2)
         # OK with nan2zero false
-        with pytest.warns(warn_type) if warn_type else error_warnings():
+        with pytest.warns(c_and_n_warn) if c_and_n_warn else error_warnings():
             back_arr = write_return(arr, fobj, np.int8,
                                     intercept=257.1, divslope=2, nan2zero=False)
         assert_array_equal([-128, -128, -128, nan_cast], back_arr)