grass.pygrass: VisibleMapset: fix reading search path

[petrasovaa]

VisibleMapset class was not reading search path properly, instead it was always just writing PERMANENT only into the path.

[tmszi]

Tested and work as expected.

[tmszi]

It requires modifying the GridModule class tests.

[tmszi]

Complex test with 3c8d6b8:

1. SEARCH_PATH file doesn't exists (passed):

GRASS nc_spm_08_grass7/landsat:~ > file grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH: cannot open `grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH' (No such file or directory)

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets -p
Accessible mapsets:
landsat PERMANENT

GRASS nc_spm_08_grass7/landsat:~ > cat /tmp/visible_mapset_test.py 
#!/usr/bin/env python3

import sys

from grass.pygrass.gis import VisibleMapset

def main():
    vm = VisibleMapset(mapset=sys.argv[1])
    print(vm.read())

if __name__ == '__main__':
    main()

GRASS nc_spm_08_grass7/landsat:~ > python /tmp/visible_mapset_test.py $(g.gisenv get="MAPSET")
['landsat', 'PERMANENT']

2. SEARCH_PATH file is empty (passed):

GRASS nc_spm_08_grass7/landsat:~ > file grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH: empty

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets -p
Accessible mapsets:
landsat

GRASS nc_spm_08_grass7/landsat:~ > python /tmp/visible_mapset_test.py $(g.gisenv get="MAPSET")
['landsat']

3. SEARCH_PATH file exist (passed, and a new bug appear with g.mapsets module):

GRASS nc_spm_08_grass7/landsat:~ > file grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH: ASCII text

GRASS nc_spm_08_grass7/landsat:~ > cat grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat
PERMANENT
climate_2000_2012

GRASS nc_spm_08_grass7/landsat:~ > python /tmp/visible_mapset_test.py $(g.gisenv get="MAPSET")
['landsat', 'PERMANENT', 'climate_2000_2012', '']

It seems that with this last test example (Python code output) we have an extra unnecessary empty '' MAPSET name due the g.mapsets module writing an extra \n to the SEARCH_PATH file. PR #2586.

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$
$

[tmszi]

open file func mode param arg should be "r" only according output bellow and we don't need decode readed lines:

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets operation=set mapset=landsat

GRASS nc_spm_08_grass7/landsat:~ > file grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH: ASCII text

Same for _write() method, open file func with mode param arg should be w only.

    def _write(self, mapsets):
        """Write to SEARCH_PATH file the changes in the search path

        :param list mapsets: a list of mapset's names
        """
        with open(self.spath, "w") as f:
            f.write("\n".join([m for m in mapsets if m in self.location.mapsets()]))

extend() method without decode func

    def extend(self, mapsets):
        """Add more mapsets to the search path

        :param list mapsets: a list of mapset's names
        """
        final = self.read()
        final.extend(
            [
                m
                for m in mapsets
                if m in self.location.mapsets() and m not in final
            ]
        )
        self._write(final)

[tmszi]

Small note (it is not bug):

g.mapsets module write \n on the EOF for every line in the SEARCH_PATH file:

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets operation=set mapset=landsat

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets operation=add mapset=PERMANENT

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$

VisibleMapset class instance _write method do not write \n on the EOF on the last line in the SEARCH_PATH file:

GRASS nc_spm_08_grass7/landsat:~ > g.mapsets -l
Available mapsets:
PERMANENT climate_2000_2012 landsat tomas

GRASS nc_spm_08_grass7/landsat:~ > cat /tmp/test.py
#!/usr/bin/env python3

import sys

from grass.pygrass.gis import VisibleMapset

def main():
    vm = VisibleMapset(mapset=sys.argv[1])
    vm.extend(["climate_2000_2012", "tomas"])
    print(vm.read())

if __name__ == '__main__':
    main()

GRASS nc_spm_08_grass7/landsat:~ > python /tmp/test.py $(g.gisenv get="MAPSET")
['landsat', 'PERMANENT', 'climate_2000_2012', 'tomas']

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$
tomasGRASS nc_spm_08_grass7/landsat:~ >

tomasGRASS nc_spm_08_grass7/landsat:~ > this line should be (missing $ which is \n)

tomas$
GRASS nc_spm_08_grass7/landsat:~ >

Fixed with (line 459):

eof = "\n"
f.write(eof.join([m for m in mapsets if m in ms]) + eof)

and (line 469):

f.write("%s\n" % mapset)

[petrasovaa]

No I got confused, didn't you @tmszi change the behavior of g.mapsets in #2586 to avoid writing the newline at the end? Should I revert the last commit in this PR?

[tmszi]

No I got confused, didn't you @tmszi change the behavior of g.mapsets in #2586 to avoid writing the newline at the end? Should I revert the last commit in this PR?

With PR #2586 I solve problem with additional empty line ($ == \n) when g.mapsets module write to the SEARCH_PATH file.

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$
$

should be

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$

VisibleMapset class instance _write() method don't write \n on the last line ($ == \n) MAPSET -> MAPSET\n and your last commit a3e05df solve it and is needed:

Example when _write() method write to SEARCH_PATH file:

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$
tomasGRASS nc_spm_08_grass7/landsat:~ >

should be

GRASS nc_spm_08_grass7/landsat:~ > cat -e grassdata/nc_spm_08_grass7/landsat/SEARCH_PATH 
landsat$
PERMANENT$
climate_2000_2012$
tomas$
GRASS nc_spm_08_grass7/landsat:~ >

this line tomasGRASS nc_spm_08_grass7/landsat:~ > should be (missing \n on the EOF tomas to tomas$)

tomas$
GRASS nc_spm_08_grass7/landsat:~ >

[tmszi]

Could we move forward with this PR, please?