diff --git a/array_api_tests/pytest_helpers.py b/array_api_tests/pytest_helpers.py
index 2cb78cb0..64e39aa4 100644
--- a/array_api_tests/pytest_helpers.py
+++ b/array_api_tests/pytest_helpers.py
@@ -204,18 +204,19 @@ def assert_scalar_equals(
     out: Scalar,
     expected: Scalar,
     /,
+    repr_name: str = "out",
     **kw,
 ):
-    out_repr = "out" if idx == () else f"out[{idx}]"
+    repr_name = repr_name if idx == () else f"{repr_name}[{idx}]"
     f_func = f"{func_name}({fmt_kw(kw)})"
     if type_ is bool or type_ is int:
-        msg = f"{out_repr}={out}, but should be {expected} [{f_func}]"
+        msg = f"{repr_name}={out}, but should be {expected} [{f_func}]"
         assert out == expected, msg
     elif math.isnan(expected):
-        msg = f"{out_repr}={out}, but should be {expected} [{f_func}]"
+        msg = f"{repr_name}={out}, but should be {expected} [{f_func}]"
         assert math.isnan(out), msg
     else:
-        msg = f"{out_repr}={out}, but should be roughly {expected} [{f_func}]"
+        msg = f"{repr_name}={out}, but should be roughly {expected} [{f_func}]"
         assert math.isclose(out, expected, rel_tol=0.25, abs_tol=1), msg
 
 
diff --git a/array_api_tests/test_array_object.py b/array_api_tests/test_array_object.py
index 78385cbe..397d823d 100644
--- a/array_api_tests/test_array_object.py
+++ b/array_api_tests/test_array_object.py
@@ -10,6 +10,7 @@
 from . import dtype_helpers as dh
 from . import hypothesis_helpers as hh
 from . import pytest_helpers as ph
+from . import shape_helpers as sh
 from . import xps
 from .typing import DataType, Param, Scalar, ScalarType, Shape
 
@@ -87,6 +88,7 @@ def test_setitem(shape, data):
     )
     x = xp.asarray(obj, dtype=dtype)
     note(f"{x=}")
+    # TODO: test setting non-0d arrays
     key = data.draw(xps.indices(shape=shape, max_dims=0), label="key")
     value = data.draw(
         xps.from_dtype(dtype) | xps.arrays(dtype=dtype, shape=()), label="value"
@@ -104,10 +106,100 @@ def test_setitem(shape, data):
         else:
             assert res[key] == value, msg
     else:
-        ph.assert_0d_equals("__setitem__", "value", value, f"x[{key}]", res[key])
+        ph.assert_0d_equals(
+            "__setitem__", "value", value, f"modified x[{key}]", res[key]
+        )
+    _key = key if isinstance(key, tuple) else (key,)
+    assume(all(isinstance(i, int) for i in _key))  # TODO: normalise slices and ellipsis
+    _key = tuple(i if i >= 0 else s + i for i, s in zip(_key, x.shape))
+    unaffected_indices = list(sh.ndindex(res.shape))
+    unaffected_indices.remove(_key)
+    for idx in unaffected_indices:
+        ph.assert_0d_equals(
+            "__setitem__", f"old x[{idx}]", x[idx], f"modified x[{idx}]", res[idx]
+        )
+
+
+# TODO: make mask tests optional
+
+
+@given(hh.shapes(), st.data())
+def test_getitem_masking(shape, data):
+    x = data.draw(xps.arrays(xps.scalar_dtypes(), shape=shape), label="x")
+    mask_shapes = st.one_of(
+        st.sampled_from([x.shape, ()]),
+        st.lists(st.booleans(), min_size=x.ndim, max_size=x.ndim).map(
+            lambda l: tuple(s if b else 0 for s, b in zip(x.shape, l))
+        ),
+        hh.shapes(),
+    )
+    key = data.draw(xps.arrays(dtype=xp.bool, shape=mask_shapes), label="key")
 
+    if key.ndim > x.ndim or not all(
+        ks in (xs, 0) for xs, ks in zip(x.shape, key.shape)
+    ):
+        with pytest.raises(IndexError):
+            x[key]
+        return
+
+    out = x[key]
 
-# TODO: test boolean indexing
+    ph.assert_dtype("__getitem__", x.dtype, out.dtype)
+    if key.ndim == 0:
+        out_shape = (1,) if key else (0,)
+        out_shape += x.shape
+    else:
+        size = int(xp.sum(xp.astype(key, xp.uint8)))
+        out_shape = (size,) + x.shape[key.ndim :]
+    ph.assert_shape("__getitem__", out.shape, out_shape)
+    if not any(s == 0 for s in key.shape):
+        assume(key.ndim == x.ndim)  # TODO: test key.ndim < x.ndim scenarios
+        out_indices = sh.ndindex(out.shape)
+        for x_idx in sh.ndindex(x.shape):
+            if key[x_idx]:
+                out_idx = next(out_indices)
+                ph.assert_0d_equals(
+                    "__getitem__",
+                    f"x[{x_idx}]",
+                    x[x_idx],
+                    f"out[{out_idx}]",
+                    out[out_idx],
+                )
+
+
+@given(hh.shapes(), st.data())
+def test_setitem_masking(shape, data):
+    x = data.draw(xps.arrays(xps.scalar_dtypes(), shape=shape), label="x")
+    key = data.draw(xps.arrays(dtype=xp.bool, shape=shape), label="key")
+    value = data.draw(
+        xps.from_dtype(x.dtype) | xps.arrays(dtype=x.dtype, shape=()), label="value"
+    )
+
+    res = xp.asarray(x, copy=True)
+    res[key] = value
+
+    ph.assert_dtype("__setitem__", x.dtype, res.dtype, repr_name="x.dtype")
+    ph.assert_shape("__setitem__", res.shape, x.shape, repr_name="x.dtype")
+    scalar_type = dh.get_scalar_type(x.dtype)
+    for idx in sh.ndindex(x.shape):
+        if key[idx]:
+            if isinstance(value, Scalar):
+                ph.assert_scalar_equals(
+                    "__setitem__",
+                    scalar_type,
+                    idx,
+                    scalar_type(res[idx]),
+                    value,
+                    repr_name="modified x",
+                )
+            else:
+                ph.assert_0d_equals(
+                    "__setitem__", "value", value, f"modified x[{idx}]", res[idx]
+                )
+        else:
+            ph.assert_0d_equals(
+                "__setitem__", f"old x[{idx}]", x[idx], f"modified x[{idx}]", res[idx]
+            )
 
 
 def make_param(method_name: str, dtype: DataType, stype: ScalarType) -> Param: