Fix istft and add class TestMathErrors in ops/math_test.py (#19594)

* Fix and test math functions for jax backend

* run /workspaces/keras/shell/format.sh

* refix

* fix

* fix _get_complex_tensor_from_tuple

* fix

* refix

* Fix istft function to handle inputs with less than 2 dimensions

* fix

* Fix ValueError in istft function for inputs with less than 2 dimensions

Author: Faisal-Alsrheed

keras/src/backend/jax/math.py

@@ -204,6 +204,12 @@ def istft(
     x = _get_complex_tensor_from_tuple(x)
     dtype = jnp.real(x).dtype
 
+    if len(x.shape) < 2:
+        raise ValueError(
+            f"Input `x` must have at least 2 dimensions. "
+            f"Received shape: {x.shape}"
+        )
+
     expected_output_len = fft_length + sequence_stride * (x.shape[-2] - 1)
     l_pad = (fft_length - sequence_length) // 2
     r_pad = fft_length - sequence_length - l_pad

keras/src/ops/linalg_test.py

@@ -101,6 +101,15 @@ def test_qr(self):
         self.assertEqual(q.shape, qref_shape)
         self.assertEqual(r.shape, rref_shape)
 
+    def test_qr_invalid_mode(self):
+        # backend agnostic error message
+        x = np.array([[1, 2], [3, 4]])
+        invalid_mode = "invalid_mode"
+        with self.assertRaisesRegex(
+            ValueError, "Expected one of {'reduced', 'complete'}."
+        ):
+            linalg.qr(x, mode=invalid_mode)
+
     def test_solve(self):
         a = KerasTensor([None, 20, 20])
         b = KerasTensor([None, 20, 5])

keras/src/ops/math_test.py

@@ -1,5 +1,6 @@
 import math
 
+import jax.numpy as jnp
 import numpy as np
 import pytest
 import scipy.signal
@@ -1256,3 +1257,90 @@ def test_undefined_fft_length_and_last_dimension(self):
         expected_shape = real_part.shape[:-1] + (None,)
 
         self.assertEqual(output_spec.shape, expected_shape)
+
+
+class TestMathErrors(testing.TestCase):
+
+    @pytest.mark.skipif(
+        backend.backend() != "jax", reason="Testing Jax errors only"
+    )
+    def test_segment_sum_no_num_segments(self):
+        data = jnp.array([1, 2, 3, 4])
+        segment_ids = jnp.array([0, 0, 1, 1])
+        with self.assertRaisesRegex(
+            ValueError,
+            "Argument `num_segments` must be set when using the JAX backend.",
+        ):
+            kmath.segment_sum(data, segment_ids)
+
+    @pytest.mark.skipif(
+        backend.backend() != "jax", reason="Testing Jax errors only"
+    )
+    def test_segment_max_no_num_segments(self):
+        data = jnp.array([1, 2, 3, 4])
+        segment_ids = jnp.array([0, 0, 1, 1])
+        with self.assertRaisesRegex(
+            ValueError,
+            "Argument `num_segments` must be set when using the JAX backend.",
+        ):
+            kmath.segment_max(data, segment_ids)
+
+    def test_stft_invalid_input_type(self):
+        # backend agnostic error message
+        x = np.array([1, 2, 3, 4])
+        sequence_length = 2
+        sequence_stride = 1
+        fft_length = 4
+        with self.assertRaisesRegex(TypeError, "`float32` or `float64`"):
+            kmath.stft(x, sequence_length, sequence_stride, fft_length)
+
+    def test_invalid_fft_length(self):
+        # backend agnostic error message
+        x = np.array([1.0, 2.0, 3.0, 4.0])
+        sequence_length = 4
+        sequence_stride = 1
+        fft_length = 2
+        with self.assertRaisesRegex(ValueError, "`fft_length` must equal or"):
+            kmath.stft(x, sequence_length, sequence_stride, fft_length)
+
+    def test_stft_invalid_window(self):
+        # backend agnostic error message
+        x = np.array([1.0, 2.0, 3.0, 4.0])
+        sequence_length = 2
+        sequence_stride = 1
+        fft_length = 4
+        window = "invalid_window"
+        with self.assertRaisesRegex(ValueError, "If a string is passed to"):
+            kmath.stft(
+                x, sequence_length, sequence_stride, fft_length, window=window
+            )
+
+    def test_stft_invalid_window_shape(self):
+        # backend agnostic error message
+        x = np.array([1.0, 2.0, 3.0, 4.0])
+        sequence_length = 2
+        sequence_stride = 1
+        fft_length = 4
+        window = np.ones((sequence_length + 1))
+        with self.assertRaisesRegex(ValueError, "The shape of `window` must"):
+            kmath.stft(
+                x, sequence_length, sequence_stride, fft_length, window=window
+            )
+
+    def test_istft_invalid_window_shape_2D_inputs(self):
+        # backend agnostic error message
+        x = (np.array([[1.0, 2.0]]), np.array([[3.0, 4.0]]))
+        sequence_length = 2
+        sequence_stride = 1
+        fft_length = 4
+        incorrect_window = np.ones((sequence_length + 1,))
+        with self.assertRaisesRegex(
+            ValueError, "The shape of `window` must be equal to"
+        ):
+            kmath.istft(
+                x,
+                sequence_length,
+                sequence_stride,
+                fft_length,
+                window=incorrect_window,
+            )