Improvements to test_solve

- Fix it to only generate arguments with mutually promotable dtypes
- Test dtype promotion
- Test output shape

Author: asmeurer

array_api_tests/test_linalg.py

@@ -597,32 +597,42 @@ def solve_args():
     of shape (..., M, M), and x2 is either shape (M,) or (..., M, K),
     where the ... parts of x1 and x2 are broadcast compatible.
     """
+    mutual_dtypes = shared(mutually_promotable_dtypes(dtypes=dh.all_float_dtypes))
+
     stack_shapes = shared(two_mutually_broadcastable_shapes)
     # Don't worry about dtypes since all floating dtypes are type promotable
     # with each other.
-    x1 = shared(invertible_matrices(stack_shapes=stack_shapes.map(lambda pair:
-                                                                  pair[0])))
+    x1 = shared(invertible_matrices(
+        stack_shapes=stack_shapes.map(lambda pair: pair[0]),
+        dtypes=mutual_dtypes.map(lambda pair: pair[0])))
 
     @composite
     def _x2_shapes(draw):
         end = draw(integers(0, SQRT_MAX_ARRAY_SIZE))
         return draw(stack_shapes)[1] + draw(x1).shape[-1:] + (end,)
 
     x2_shapes = one_of(x1.map(lambda x: (x.shape[-1],)), _x2_shapes())
-    x2 = arrays(dtype=all_floating_dtypes(), shape=x2_shapes)
+    x2 = arrays(shape=x2_shapes, dtype=mutual_dtypes.map(lambda pair: pair[1]))
     return x1, x2
 
 @pytest.mark.xp_extension('linalg')
 @given(*solve_args())
 def test_solve(x1, x2):
     res = linalg.solve(x1, x2)
 
+    ph.assert_dtype("solve", in_dtype=[x1.dtype, x2.dtype], out_dtype=res.dtype)
     if x2.ndim == 1:
+        expected_shape = x1.shape[:-2] + x2.shape[-1:]
         _test_stacks(linalg.solve, x1, x2, res=res, dims=1,
                      matrix_axes=[(-2, -1), (0,)], res_axes=[-1])
     else:
+        stack_shape = sh.broadcast_shapes(x1.shape[:-2], x2.shape[:-2])
+        expected_shape = stack_shape + x2.shape[-2:]
         _test_stacks(linalg.solve, x1, x2, res=res, dims=2)
 
+    ph.assert_result_shape("solve", in_shapes=[x1.shape, x2.shape],
+                           out_shape=res.shape, expected=expected_shape)
+
 @pytest.mark.xp_extension('linalg')
 @given(
     x=finite_matrices(),