Fix bounds_error=True ignored with 1D interpolation

xarray/core/missing.py

@@ -154,7 +154,7 @@ def __init__(
             yi,
             kind=self.method,
             fill_value=fill_value,
-            bounds_error=False,
+            bounds_error=bounds_error,
             assume_sorted=assume_sorted,
             copy=copy,
             **self.cons_kwargs,

xarray/tests/test_interp.py

@@ -866,3 +866,20 @@ def test_interpolate_chunk_advanced(method):
     z = z.chunk(3)
     actual = da.interp(t=0.5, x=x, y=y, z=z, kwargs=kwargs, method=method)
     assert_identical(actual, expected)
+
+
+@requires_scipy
+@pytest.mark.parametrize("bounds_error", [True, False])
+def test_interp1d_bounds_error(bounds_error):
+    """Ensure exception on bounds error is raised if requested"""
+    da = xr.DataArray(
+        np.sin(0.3 * np.arange(4)),
+        [("time", np.arange(4))],
+    )
+
+    if bounds_error:
+        with pytest.raises(ValueError):
+            da.interp(time=3.5, kwargs=dict(bounds_error=bounds_error))
+    else:
+        # default is to fill with nans, so this should pass
+        da.interp(time=3.5, kwargs=dict(bounds_error=bounds_error))