Test cov minibatch (#252)

* TST cover runtime error in minibatch

* CI update codecov version

* MNT avoid using flat badge

Author: MatthewSZhang

.github/workflows/test.yml

@@ -57,7 +57,7 @@ jobs:
           pixi run -e dev test-coverage xml
       - name: Upload coverage reports to Codecov
         if: matrix.os == 'ubuntu-latest'
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v7
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           verbose: true

README.rst

@@ -23,10 +23,10 @@ fastcan: A fast canonical-correlation-based search algorithm
 .. |ruff| image:: https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json
    :target: https://github.com/astral-sh/ruff
 
-.. |pixi| image:: https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/prefix-dev/pixi/main/assets/badge/v0.json&style=flat-square
+.. |pixi| image:: https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/prefix-dev/pixi/main/assets/badge/v0.json
    :target: https://pixi.sh
 
-.. |asv| image:: https://img.shields.io/badge/benchmarked%20by-asv-blue.svg?style=flat
+.. |asv| image:: https://img.shields.io/badge/benchmarked%20by-asv-blue.svg
    :target: https://contrib.scikit-learn.org/fastcan/
 
 .. |ty| image:: https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ty/main/assets/badge/v0.json

fastcan/tests/test_minibatch.py

@@ -118,3 +118,12 @@ def test_minibatch_ssc_aligned(capsys):
         f"Progress: {n_to_select}/{n_to_select}, "
         f"Batch SSC: {gtruth_ssc:.5f}" in captured.out
     )
+
+
+def test_minibatch_runtime_error():
+    # Test RuntimeError branch when not enough features can form a non-singular matrix
+    X = np.array([[1.0, 1.0], [2.0, 2.0], [3.0, 3.0], [4.0, 4.0]])
+    y = np.array([1.0, 2.0, 3.0, 4.0])
+
+    indices = minibatch(X, y, n_features_to_select=2, batch_size=2, verbose=0)
+    assert len(np.unique(indices)) == 2