Replace check of empty string in unfilled template widgets to None

[edan-bainglass]

This PR corrects a guard for unfilled template variables which checks if the value of the corresponding widget is an empty string. Empty widgets may also be represented by None, especially dropdown selectors. This PR adds None to the check by comparing the widget's value to both - replaces == "" with in ("", None).

Resolves #648
Resolves #651

@superstar54 @danielhollas have a look 🙏
@unkcpz tagging you due to git blame (suggests you implemented these sections)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.45%. Comparing base (7a93035) to head (90e4ba5).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #650      +/-   ##
==========================================
- Coverage   83.46%   83.45%   -0.01%     
==========================================
  Files          17       17              
  Lines        3568     3566       -2     
==========================================
- Hits         2978     2976       -2     
  Misses        590      590              

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python-3.11	83.45% <100.00%> (-0.01%)	⬇️
python-3.9	83.49% <100.00%> (-0.01%)	⬇️

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[danielhollas]

LGTM but I am not familiar with the template code at all so this better be reviewed by somebody that does :-)

[danielhollas]

Also thanks for following up on this @edan-bainglass! 🤟

[edan-bainglass]

LGTM but I am not familiar with the template code at all so this better be reviewed by somebody that does :-)

100% why I tagged @unkcpz 😅

[edan-bainglass]

@unkcpz can you have a look at this?

[unkcpz]

Thanks @edan-bainglass, I think it is a correct change, None was what I didn't considered when initialize the widget value. This will for sure directly solve #648

Not sure it is easy to understand logic of testing, but when I created this widget, I tried to catch most of conditions with tests in

aiidalab-widgets-base/tests/test_computational_resources.py

Lines 318 to 372 in 7a93035

	def test_template_variables_widget():
	"""Test template_variables_widget."""
	w = computational_resources.TemplateVariablesWidget()
	w.templates = {
	"label": "{{ label }}",
	"hostname": "daint.cscs.ch",
	"description": "Piz Daint supercomputer at CSCS Lugano, Switzerland, multicore partition.",
	"transport": "core.ssh",
	"scheduler": "core.slurm",
	"work_dir": "/scratch/snx3000/{username}/aiida_run/",
	"shebang": "#!/bin/bash",
	"mpirun_command": "srun -n {tot_num_mpiprocs}",
	"mpiprocs_per_machine": 36,
	"prepend_text": "#SBATCH --partition={{ slurm_partition }}\n#SBATCH --account={{ slurm_account }}\n#SBATCH --constraint=mc\n#SBATCH --cpus-per-task=1\n\nexport OMP_NUM_THREADS=$SLURM_CPUS_PER_TASK\nsource $MODULESHOME/init/bash\nulimit -s unlimited",
	"metadata": {
	"slurm_partition": {
	"type": "text",
	"key_display": "Slurm partition",
	},
	},
	}
	# Fill the template variables
	for key, value in w._template_variables.items():
	if key == "label":
	sub_widget = value.widget
	sub_widget.value = "daint-mc-test"
	# check the filled value is updated in the filled template
	assert w.filled_templates["label"] == "daint-mc-test"
	# Fill two template variables in one template line
	for key, value in w._template_variables.items():
	if key == "slurm_partition":
	sub_widget = value.widget
	sub_widget.value = "normal-test"
	elif key == "slurm_account":
	sub_widget = value.widget
	sub_widget.value = "newuser"
	# check the filled value is updated in the filled template
	assert (
	w.filled_templates["prepend_text"]
	== "#SBATCH --partition=normal-test\n#SBATCH --account=newuser\n#SBATCH --constraint=mc\n#SBATCH --cpus-per-task=1\n\nexport OMP_NUM_THREADS=$SLURM_CPUS_PER_TASK\nsource $MODULESHOME/init/bash\nulimit -s unlimited"
	)
	# Test the filled template is updated when the filled value is updated.
	for key, value in w._template_variables.items():
	if key == "slurm_partition":
	sub_widget = value.widget
	sub_widget.value = "debug"
	assert "debug" in w.filled_templates["prepend_text"]

. Would you mind to give it a look to add a test for this None situation? I guess you can add #648 example as test and use the change of this PR to test it.