CoverageData with no_disk does not update correctly · Issue #1323 · nedbat/coveragepy (original) (raw)

Describe the bug

A CoverageData constructed with no_disk=True cannot be updated with another CoverageData. The operation succeeds but records nothing:

from coverage import CoverageData a = CoverageData('.foo')
a.add_arcs({'foo.py': {}})
a.measured_files()
{'foo.py'}

b = CoverageData(no_disk=True)
b.update(a)
b.measured_files()
set()

(This applies also for arcs etc., b remains empty).

Expected behavior

The expected behaviour for no_disk=True is the same as when no_disk is left unspecified; after an update() call we should see data in the updated CoverageData:

c = CoverageData() c.update(a)
c.measured_files() {'foo.py'}

To Reproduce

1. What version of Python are you using? 3.9.7
2. What version of coverage.py shows the problem? 6.3.1
3. The output of coverage debug sys is helpful.

It's very long due to a tremendously long PYTHONPATH, but perhaps this part is most relevant:

                sqlite3_version: 2.6.0                                                 
         sqlite3_sqlite_version: 3.36.0                                                
             sqlite3_temp_store: 0                                                     
        sqlite3_compile_options: COMPILER=gcc-8.3.0; ENABLE_FTS4; ENABLE_FTS5          
                                 ENABLE_GEOPOLY; ENABLE_JSON1; ENABLE_MATH_FUNCTIONS   
                                 ENABLE_RTREE; MAX_MMAP_SIZE=17179869184; SYSTEM_MALLOC
                                 THREADSAFE=1