[tests] refactor tests

meanas/test/_test_builders.py

@@ -0,0 +1,22 @@
+import numpy
+
+
+def real_ramp(shape: tuple[int, ...], *, scale: float = 1.0, offset: float = 0.0) -> numpy.ndarray:
+    return numpy.arange(numpy.prod(shape), dtype=float).reshape(shape, order='C') * scale + offset
+
+
+def complex_ramp(
+        shape: tuple[int, ...],
+        *,
+        scale: float = 1.0,
+        offset: float = 0.0,
+        imag_scale: float = 0.0,
+        imag_offset: float = 0.0,
+        ) -> numpy.ndarray:
+    real = real_ramp(shape, scale=scale, offset=offset)
+    imag = real_ramp(shape, scale=imag_scale, offset=imag_offset)
+    return (real + 1j * imag).astype(complex)
+
+
+def unit_dxes(shape: tuple[int, ...]) -> tuple[tuple[numpy.ndarray, ...], tuple[numpy.ndarray, ...]]:
+    return tuple(tuple(numpy.ones(length) for length in shape) for _ in range(2))  # type: ignore[return-value]