854 Allow null event range

#854

[author: gonzaponte]

This PR adds the option to run a city with `event_range = 0`, which can
be useful for testing.

Closes #573

[reviewer: martinperezmaneiro]

Good PR. Adds protection to `slice` function for `event_range = 0`,
and creates the corresponding test. Also changes a file structure test
to run over no events. Everything works as expected :)

Author: martinperezmaneiro

invisible_cities/cities/cities_test.py

@@ -10,10 +10,12 @@
 
 from .. core.configure      import configure
 
-online_cities = "irene dorothea sophronia esmeralda beersheba".split()
-all_cities    = """beersheba berenice buffy detsim diomira dorothea esmeralda
-                   eutropia hypathia irene isaura isidora phyllis sophronia
-                   trude""".split()
+online_cities  = "irene dorothea sophronia esmeralda beersheba isaura".split()
+mc_cities      = "buffy detsim diomira hypathia".split()
+other_cities   = "berenice isidora phyllis trude eutropia".split()
+all_cities     = sorted(online_cities + mc_cities + other_cities)
+all_cities_with_event_range = sorted(set(all_cities).difference(set(["eutropia"])))
+
 
 @mark.filterwarnings("ignore::UserWarning")
 @mark.parametrize("city", online_cities)
@@ -35,6 +37,23 @@ def test_city_empty_input_file(config_tmpdir, ICDATADIR, city):
     city_function(**conf)
 
 
+@mark.filterwarnings("ignore::UserWarning")
+@mark.parametrize("city", all_cities_with_event_range)
+def test_city_null_event_range(config_tmpdir, ICDATADIR, city):
+    # All cities must run with event_range = 0
+    PATH_OUT = os.path.join(config_tmpdir, 'empty_output.h5')
+
+    config_file = 'dummy invisible_cities/config/{}.conf'.format(city)
+    conf = configure(config_file.split())
+    conf.update(dict( file_out = PATH_OUT
+                     , event_range = 0))
+
+    module_name   = f'invisible_cities.cities.{city}'
+    city_function = getattr(import_module(module_name), city)
+
+    city_function(**conf)
+
+
 
 @mark.filterwarnings("ignore::UserWarning")
 @mark.parametrize("city", all_cities)
@@ -43,22 +62,28 @@ def test_city_output_file_is_compressed(config_tmpdir, ICDATADIR, city):
     config_file = 'dummy invisible_cities/config/{}.conf'.format(city)
 
     conf = configure(config_file.split())
-    conf.update(dict(file_out = file_out))
+    conf.update(dict( file_out    = file_out
+                    , event_range = 0))
 
     module_name   = f'invisible_cities.cities.{city}'
     city_function = getattr(import_module(module_name), city)
 
     city_function(**conf)
 
+    checked_nodes = 0
     with tb.open_file(file_out) as file:
         for node in chain([file], file.walk_nodes()):
             try:
                 assert (node.filters.complib   is not None and
                         node.filters.complevel > 0)
+                checked_nodes += 1
 
             except tb.NoSuchNodeError:
                 continue
 
+    # ensure that we didn't pass the test because there were no nodes checked
+    assert checked_nodes > 2
+
 
 @mark.filterwarnings("ignore::UserWarning")
 @mark.parametrize("city", all_cities)

invisible_cities/dataflow/dataflow.py

@@ -324,6 +324,7 @@ def string_to_pick(component):
 def slice(*args, close_all=False):
     spec = builtins.slice(*args)
     start, stop, step = spec.start, spec.stop, spec.step
+
     if start is not None and start <  0: raise ValueError('slice requires start >= 0')
     if stop  is not None and stop  <  0: raise ValueError('slice requires stop >= 0')
     if step  is not None and step  <= 0: raise ValueError('slice requires step > 0')
@@ -332,13 +333,19 @@ def slice(*args, close_all=False):
     if step  is None: step  = 1
     if stop  is None: stopper = it.count()
     else            : stopper = range((stop - start + step - 1) // step)
+
     @coroutine
     def slice_loop(target):
         with closing(target):
-            for _ in range(start)             : yield
+            # ensures that we yield at least once in case of
+            # stop<=start to avoid raising StopPipeline without
+            # yielding first
+            if stop is not None and start >= stop : yield
+
+            for _ in range(start)                 : yield
             for _ in stopper:
                 target.send((yield))
-                for _ in range(step - 1)      : yield
+                for _ in range(step - 1)          : yield
             if close_all: raise StopPipeline
             while True:
                 yield

invisible_cities/dataflow/dataflow_test.py

@@ -465,20 +465,33 @@ def intercalate(a,b):
               tuples(small_ints, small_ints),
               tuples(slice_arg,  slice_arg, slice_arg_nonzero)))
 def test_slice_downstream(spec):
-
     the_source = list('abcdefghij')
     result = []
     the_sink = df.sink(result.append)
 
     df.push(source = the_source,
-            pipe   = df.pipe(df.slice(*spec), the_sink))
+            pipe   = df.pipe(df.slice(*spec, close_all=False), the_sink))
+
 
     specslice = slice(*spec)
     assert result == the_source[specslice]
     assert result == the_source[specslice.start : specslice.stop : specslice.step]
 
 
-#TODO: Write test slice_close_all
+def test_slice_null_close_all():
+    spec       = (0,)
+
+    the_source = list('abcdefghij')
+    result     = []
+    the_sink   = df.sink(result.append)
+
+    df.push(source = the_source,
+            pipe   = df.pipe(df.slice(*spec, close_all=True), the_sink))
+
+    specslice = slice(*spec)
+    assert result == the_source[specslice]
+    assert result == the_source[specslice.start : specslice.stop : specslice.step]
+
 
 @parametrize('args',
              ((      -1,),