add test_chi2_contigency

Author: Aniketsy

tests/stats/test_chi2_contingency.pyi

@@ -0,0 +1,33 @@
+# type-tests for `scipy.stats.chi2_contingency` top-level export
+
+from typing import assert_type
+
+import numpy as np
+import optype.numpy as onp
+
+from scipy.stats import chi2_contingency
+from scipy.stats.contingency import Chi2ContingencyResult
+
+###
+
+_f32_2d: onp.Array2D[np.float32]
+_f64_2d: onp.Array2D[np.float64]
+_f64_3d: onp.Array3D[np.float64]
+_f64_nd: onp.ArrayND[np.float64]
+
+###
+
+assert_type(chi2_contingency(_f32_2d, correction=False), Chi2ContingencyResult[tuple[int, int]])
+assert_type(chi2_contingency(_f64_2d, correction=False), Chi2ContingencyResult[tuple[int, int]])
+assert_type(chi2_contingency(_f64_3d, correction=False), Chi2ContingencyResult[tuple[int, int, int]])
+assert_type(chi2_contingency(_f64_nd, correction=False), Chi2ContingencyResult)
+assert_type(chi2_contingency(_f64_2d), Chi2ContingencyResult[tuple[int, int]])
+assert_type(chi2_contingency(_f64_2d, lambda_="log-likelihood"), Chi2ContingencyResult[tuple[int, int]])
+
+###
+
+res = chi2_contingency(_f64_2d)
+assert_type(res.statistic, np.float64)
+assert_type(res.pvalue, np.float64)
+assert_type(res.dof, int)
+assert_type(res.expected_freq, onp.Array2D[np.float64])