feat(test): DocumentArray method tests similar to list methods like r…

…everse, sort, remove, pop (#1291)

* feat: isort format fix

Signed-off-by: agaraman0 <agaraman0@gmail.com>

* refactor: comment fixes

Signed-off-by: agaraman0 <agaraman0@gmail.com>

* refactor: comment fixes

Signed-off-by: agaraman0 <agaraman0@gmail.com>

---------

Signed-off-by: agaraman0 <agaraman0@gmail.com>

tests/units/array/test_array.py

@@ -5,7 +5,7 @@
 import torch
 
 from docarray import BaseDocument, DocumentArray
-from docarray.typing import NdArray, TorchTensor
+from docarray.typing import ImageUrl, NdArray, TorchTensor
 from docarray.utils.misc import is_tf_available
 
 tf_available = is_tf_available()
@@ -319,3 +319,50 @@ class Text(BaseDocument):
     da = DocumentArray[Text].construct(docs)
 
     assert da._data is docs
+
+
+def test_reverse():
+    class Text(BaseDocument):
+        text: str
+
+    docs = [Text(text=f'hello {i}') for i in range(10)]
+
+    da = DocumentArray[Text](docs)
+    da.reverse()
+    assert da[-1].text == 'hello 0'
+    assert da[0].text == 'hello 9'
+
+
+class Image(BaseDocument):
+    tensor: Optional[NdArray]
+    url: ImageUrl
+
+
+def test_remove():
+    images = [Image(url=f'http://url.com/foo_{i}.png') for i in range(3)]
+    da = DocumentArray[Image](images)
+    da.remove(images[1])
+    assert len(da) == 2
+    assert da[0] == images[0]
+    assert da[1] == images[2]
+
+
+def test_pop():
+    images = [Image(url=f'http://url.com/foo_{i}.png') for i in range(3)]
+    da = DocumentArray[Image](images)
+    popped = da.pop(1)
+    assert len(da) == 2
+    assert popped == images[1]
+    assert da[0] == images[0]
+    assert da[1] == images[2]
+
+
+def test_sort():
+    images = [
+        Image(url=f'http://url.com/foo_{i}.png', tensor=NdArray(i)) for i in [2, 0, 1]
+    ]
+    da = DocumentArray[Image](images)
+    da.sort(key=lambda img: len(img.tensor))
+    assert len(da) == 3
+    assert da[0].url == 'http://url.com/foo_0.png'
+    assert da[1].url == 'http://url.com/foo_1.png'