Added get_shape as an alias for get_size + tests (matplotlib#25425)

* Added get_shapes method as alias to get_size

* merge tests and add exception test

* match the correct runtime error

* remove reduntant lines by making get_size call get_shape

* simplify further

* fix previous commit error

Author: saranti

lib/matplotlib/image.py

@@ -275,8 +275,8 @@ def __init__(self, ax,
 
     def __str__(self):
         try:
-            size = self.get_size()
-            return f"{type(self).__name__}(size={size!r})"
+            shape = self.get_shape()
+            return f"{type(self).__name__}(shape={shape!r})"
         except RuntimeError:
             return type(self).__name__
 
@@ -286,10 +286,16 @@ def __getstate__(self):
 
     def get_size(self):
         """Return the size of the image as tuple (numrows, numcols)."""
+        return self.get_shape()[:2]
+
+    def get_shape(self):
+        """
+        Return the shape of the image as tuple (numrows, numcols, channels).
+        """
         if self._A is None:
             raise RuntimeError('You must first set the image array')
 
-        return self._A.shape[:2]
+        return self._A.shape
 
     def set_alpha(self, alpha):
         """

lib/matplotlib/tests/test_image.py

@@ -1468,3 +1468,15 @@ def test__resample_valid_output():
         resample(np.zeros((9, 9), np.uint8), np.zeros((9, 9)))
     with pytest.raises(ValueError, match="must be C-contiguous"):
         resample(np.zeros((9, 9)), np.zeros((9, 9)).T)
+
+
+def test_axesimage_get_shape():
+    # generate dummy image to test get_shape method
+    ax = plt.gca()
+    im = AxesImage(ax)
+    with pytest.raises(RuntimeError, match="You must first set the image array"):
+        im.get_shape()
+    z = np.arange(12, dtype=float).reshape((4, 3))
+    im.set_data(z)
+    assert im.get_shape() == (4, 3)
+    assert im.get_size() == im.get_shape()