fix: rewrite test to use fixtures and new data

nireports/conftest.py

@@ -33,7 +33,7 @@
 # disable ET
 os.environ['NO_ET'] = '1'
 
-_datadir = (Path(__file__).parent / "tests" / "data").resolve(strict=True)
+_datadir = (Path(__file__).parent / "tests" / "data").absolute()
 niprepsdev_path = os.getenv(
     "TEST_DATA_HOME", str(Path.home() / ".cache" / "nipreps-dev")
 )

nireports/tests/test_dwi.py

@@ -1,7 +1,7 @@
 # emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
 # vi: set ft=python sts=4 ts=4 sw=4 et:
 #
-# Copyright 2023 The NiPreps Developers <[email protected]>
+# Copyright 2024 The NiPreps Developers <[email protected]>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -20,26 +20,30 @@
 #
 #     https://www.nipreps.org/community/licensing/
 #
-from pathlib import Path
+"""Test DWI reportlets."""
+
+import pytest
 
 import numpy as np
 from matplotlib import pyplot as plt
-from dipy.io import read_bvals_bvecs
-from dipy.core.gradients import gradient_table
 
 from nireports.reportlets.modality.dwi import plot_gradients
 
 
-def test_plot_gradients(tmp_path):
+@pytest.mark.parametrize(
+    'dwi_btable',
+    ['ds000114_singleshell', 'hcph_multishell', 'ds004737_dsi'],
+)
+def test_plot_gradients(tmp_path, testdata_path, dwi_btable, outdir):
+    """Check the plot of DWI gradients."""
+
+    bvecs = np.loadtxt(testdata_path / f'{dwi_btable}.bvec').T
+    bvals = np.loadtxt(testdata_path / f'{dwi_btable}.bval')
 
-    fbval = "./mriqc/data/testdata/hcp_bvals"
-    fbvec = "./mriqc/data/testdata/hcp_bvecs"
-    _bvals, _bvecs = read_bvals_bvecs(fbval, fbvec)
-    gtab = gradient_table(_bvals, _bvecs)
-    bvecs = gtab.bvecs[~gtab.b0s_mask]
-    bvals = gtab.bvals[~gtab.b0s_mask]
+    b0s_mask = bvals < 50
 
-    gradients = np.vstack([bvecs.T, bvals])
+    gradients = np.vstack([bvecs[:, ~b0s_mask], bvals[~b0s_mask]])
     _ = plot_gradients(gradients)
 
-    plt.savefig(Path(tmp_path) / "gradients.png")
+    if outdir is not None:
+        plt.savefig(outdir / f'{dwi_btable}.svg', bbox_inches='tight')