Fix some warnings from tests

[larsevj]

Should fix the following warnings from the tests:

  /opt/hostedtoolcache/Python/3.11.13/x64/lib/python3.11/site-packages/subscript/summaryplot/summaryplot.py:452: 
MatplotlibDeprecationWarning: The plot_date function was deprecated in Matplotlib 3.9 and will be removed in 3.11. 
Use plot instead.
    pyplot.plot_date(firstsummary.dates, values, "k.", label=sumlabel)

  /opt/hostedtoolcache/Python/3.11.13/x64/lib/python3.11/site-packages/subscript/fmuobs/writers.py:299: 
FutureWarning: Downcasting behavior in `replace` is deprecated and will be removed in a future version. 
To retain the old behavior, explicitly call `result.infer_objects(copy=False)`. 
To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
    .replace(["NaT", "NaN", "nan"], np.nan)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 84.37500% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.16%. Comparing base (a199b2e) to head (701e4f4).

Files with missing lines	Patch %	Lines
src/subscript/summaryplot/summaryplot.py	82.75%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #806   +/-   ##
=======================================
  Coverage   85.16%   85.16%           
=======================================
  Files          49       49           
  Lines        7544     7544           
=======================================
  Hits         6425     6425           
  Misses       1119     1119           

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[Copilot]

Pull Request Overview

This PR fixes deprecation warnings from matplotlib and pandas in the test suite by updating deprecated function calls to their modern equivalents.

• Replaces deprecated matplotlib.pyplot.plot_date() with plt.plot() throughout the summaryplot module
• Updates pandas replace() usage to suppress future downcasting warnings with explicit options
• Adds test infrastructure for matplotlib image comparison testing

Reviewed Changes

Copilot reviewed 7 out of 19 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/test_summaryplot.py	Adds matplotlib image comparison test function and imports
tests/test_ofmvol2csv.py	Suppresses pandas date parsing warnings in test
src/subscript/summaryplot/summaryplot.py	Replaces deprecated matplotlib functions and standardizes pyplot imports
src/subscript/fmuobs/writers.py	Updates pandas replace() to use explicit downcasting options
pyproject.toml	Adds pytest-mpl dependency for matplotlib testing
.github/workflows/subscript.yml	Updates CI to use uv package manager and enable matplotlib tests
.github/workflows/codecov.yml	Updates CI to use uv package manager

Comments suppressed due to low confidence (1)

src/subscript/summaryplot/summaryplot.py:490

• [nitpick] The format string parameter should be passed as fmt keyword argument for clarity when other keyword arguments are present. Consider changing line 485 to fmt=\"-\", to maintain consistency with matplotlib's API conventions.

                plt.plot(
                    summaryfile.dates,
                    values,
                    "-",
                    color=cycledcolor,
                    label=sumlabel,
                    linewidth=1.5,
                    alpha=alpha,
                )

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[rnyb]

Not sure if it is an irrelevant question , but should we consider using webp instead of png for figures? Or maybe that is not possible for usage in tests?

[larsevj]

Not sure if it is an irrelevant question , but should we consider using webp instead of png for figures? Or maybe that is not possible for usage in tests?

I suspect that pytest-mpl only supports the png format. If one prefers to not commit the image files, then they do support hash-checking instead https://pytest-mpl.readthedocs.io/en/stable/hash_mode.html , but this will make it a bit more difficult to visually compare the results.

[rnyb]

Not sure if it is an irrelevant question , but should we consider using webp instead of png for figures? Or maybe that is not possible for usage in tests?

I suspect that pytest-mpl only supports the png format. If one prefers to not commit the image files, then they do support hash-checking instead https://pytest-mpl.readthedocs.io/en/stable/hash_mode.html , but this will make it a bit more difficult to visually compare the results.

Let's keep it as is then.

[rnyb]

LGTM