attempting to tighten test error bounds in a couple cases, hopefully results are same in cloud, and attempting to get coverage to work across multiple processes, because right now it doesn't seem to be

Author: pavelkomarov

.github/workflows/test.yml

@@ -15,9 +15,15 @@ jobs:
         with:
           python-version: '3.13' # because cvxopt binaries for 3.14 don't yet exist, and building is terrible
       - name: tests and coverage
-        run: |
+        run: | # some extra stuff here to make sure coverage works across multiprocessing
           pip install -e .[advanced,dev] coveralls
-          coverage run --source=pynumdiff --omit="pynumdiff/_version.py,pynumdiff/tests/*,pynumdiff/utils/old_pi_cruise_control.py" -m pytest -s
+          touch .coveragerc
+          echo "[run]" > .coveragerc
+          echo "concurrency = multiprocessing" >> .coveragerc
+          echo "parallel = true" >> .coveragerc
+          export COVERAGE_PROCESS_START=.coveragerc
+          coverage run --parallel-mode --source=pynumdiff --omit="pynumdiff/_version.py,pynumdiff/tests/*,pynumdiff/utils/old_pi_cruise_control.py" -m pytest -s
+          coverage combine
           coverage xml
       - uses: coverallsapp/github-action@v2
         with:

pynumdiff/tests/test_diff_methods.py

@@ -134,7 +134,7 @@ def spline_irreg_step(*args, **kwargs): return splinediff(*args, **kwargs)
                [(0, 0), (1, 1), (0, -1), (1, 1)],
                [(0, 0), (3, 3), (0, 0), (3, 3)]],
     savgoldiff: [[(-7, -7), (-13, -14), (0, -1), (0, 0)],
-                 [(-7, -7), (-13, -13), (0, -1), (0, 0)],
+                 [(-7, -8), (-13, -13), (0, -1), (0, 0)],
                  [(-2, -2), (-1, -1), (0, -1), (0, 0)],
                  [(0, -1), (0, 0), (0, 0), (1, 0)],
                  [(1, 1), (2, 2), (1, 1), (2, 2)],
@@ -193,7 +193,7 @@ def spline_irreg_step(*args, **kwargs): return splinediff(*args, **kwargs)
                           [(0, 0), (1, 0), (0, -1), (1, 0)],
                           [(1, 1), (2, 2), (1, 1), (2, 2)],
                           [(1, 1), (3, 3), (1, 1), (3, 3)]],
-    jerk_sliding: [[(-25, -25), (-16, -16), (0, -1), (1, 0)],
+    jerk_sliding: [[(-25, -25), (-16, -17), (0, -1), (1, 0)],
                    [(-14, -14), (-14, -14), (0, -1), (0, 0)],
                    [(-14, -14), (-14, -14), (0, -1), (0, 0)],
                    [(-1, -1), (0, 0), (0, -1), (0, 0)],