Sprinkle some "no cover" pragmas over the code base

Add some "no cover" to some unrecoverable exceptions
(e.g. misconfiguration) or base-class methods that are not intended to
be invoked.

Signed-off-by: Niels Thykier <niels@thykier.net>

britney.py

@@ -408,10 +408,10 @@ class Britney(object):
                           check_fields=check_fields, check_field_name=check_field_name):
         bad = []
         for f in check_fields:
-            if pkg_entry1[f] != pkg_entry2[f]:
+            if pkg_entry1[f] != pkg_entry2[f]:  # pragma: no cover
                 bad.append((f, pkg_entry1[f], pkg_entry2[f]))
 
-        if bad:
+        if bad:  # pragma: no cover
             self.log("Mismatch found %s %s %s differs" % (
                 package, pkg_entry1.version, parch), type="E")
             for f, v1, v2 in bad:
@@ -454,11 +454,11 @@ class Britney(object):
         (self.options, self.args) = parser.parse_args()
         
         # integrity checks
-        if self.options.nuninst_cache and self.options.print_uninst:
+        if self.options.nuninst_cache and self.options.print_uninst:  # pragma: no cover
             self.log("nuninst_cache and print_uninst are mutually exclusive!", type="E")
             sys.exit(1)
         # if the configuration file exists, then read it and set the additional options
-        elif not os.path.isfile(self.options.config):
+        elif not os.path.isfile(self.options.config):  # pragma: no cover
             self.log("Unable to read the configuration file (%s), exiting!" % self.options.config, type="E")
             sys.exit(1)
 
@@ -488,7 +488,7 @@ class Britney(object):
                 suite_path = getattr(self.options, suite)
                 self.suite_info[suite] = SuiteInfo(name=suite, path=suite_path, excuses_suffix=suffix)
             else:
-                if suite in {'testing', 'unstable'}:
+                if suite in {'testing', 'unstable'}:  # pragma: no cover
                     self.log("Mandatory configuration %s is not set in the config" % suite.upper(), type='E')
                     sys.exit(1)
                 self.log("Optional suite %s is not defined (config option: %s) " % (suite, suite.upper()))
@@ -508,7 +508,7 @@ class Britney(object):
         else:
             self.options.components = None
 
-        if self.options.control_files and self.options.components:
+        if self.options.control_files and self.options.components:  # pragma: no cover
             # We cannot regenerate the control files correctly when reading from an
             # actual mirror (we don't which package goes in what component etc.).
             self.log("Cannot use --control-files with mirror-layout (components)!", type="E")
@@ -526,7 +526,7 @@ class Britney(object):
             # Sort the architecture list
             allarches = sorted(self.options.architectures.split())
         else:
-            if not release_file:
+            if not release_file:  # pragma: no cover
                 self.log("No configured architectures and there is no release file for testing", type="E")
                 self.log("Please check if there is a \"Release\" file in %s" % self.suite_info['testing'].path, type="E")
                 self.log("or if the config file contains a non-empty \"ARCHITECTURES\" field", type="E")
@@ -585,7 +585,7 @@ class Britney(object):
         while step():
             no += 1
             pkg_name = get_field('Package', None)
-            if pkg_name is None:
+            if pkg_name is None:  # pragma: no cover
                 raise ValueError("Missing Package field in paragraph %d (file %s)" % (no, faux_packages_file))
             pkg_name = sys.intern(pkg_name)
             version = sys.intern(get_field('Version', '1.0-1'))
@@ -656,18 +656,18 @@ class Britney(object):
         while step():
             no += 1
             pkg_name = get_field('Fake-Package-Name', None)
-            if pkg_name is None:
+            if pkg_name is None:  # pragma: no cover
                 raise ValueError("Missing Fake-Package-Name field in paragraph %d (file %s)" % (no, constraints_file))
             pkg_name = sys.intern(pkg_name)
 
             def mandatory_field(x):
                 v = get_field(x, None)
-                if v is None:
+                if v is None:  # pragma: no cover
                     raise ValueError("Missing %s field for %s (file %s)" % (x, pkg_name, constraints_file))
                 return v
 
             constraint = mandatory_field('Constraint')
-            if constraint not in {'present-and-installable'}:
+            if constraint not in {'present-and-installable'}:  # pragma: no cover
                 raise ValueError("Unsupported constraint %s for %s (file %s)" % (constraint, pkg_name, constraints_file))
 
             self.log(" - constraint %s" % pkg_name, type='I')
@@ -690,17 +690,17 @@ class Britney(object):
                         deps.append(s[0])
                     else:
                         pkg, arch_res = s
-                        if not (arch_res.startswith('[') and arch_res.endswith(']')):
+                        if not (arch_res.startswith('[') and arch_res.endswith(']')):  # pragma: no cover
                             raise ValueError("Invalid arch-restriction on %s - should be [arch1 arch2] (for %s file %s)"
                                              % (pkg, pkg_name, constraints_file))
                         arch_res = arch_res[1:-1].split()
-                        if not arch_res:
+                        if not arch_res:  # pragma: no cover
                             msg = "Empty arch-restriction for %s: Uses comma or negation (for %s file %s)"
                             raise ValueError(msg % (pkg, pkg_name, constraints_file))
                         for a in arch_res:
                             if a == arch:
                                 deps.append(pkg)
-                            elif ',' in a or '!' in a:
+                            elif ',' in a or '!' in a:  # pragma: no cover
                                 msg = "Invalid arch-restriction for %s: Uses comma or negation (for %s file %s)"
                                 raise ValueError(msg % (pkg, pkg_name, constraints_file))
                 pkg_id = BinaryPackageId(pkg_name, faux_version, arch)
@@ -877,13 +877,13 @@ class Britney(object):
         parts = apt_pkg.parse_depends(provides_raw, False)
         nprov = []
         for or_clause in parts:
-            if len(or_clause) != 1:
+            if len(or_clause) != 1:  # pragma: no cover
                 msg = "Ignoring invalid provides in %s: Alternatives [%s]" % (str(pkg_id), str(or_clause))
                 self.log(msg, type='W')
                 continue
             for part in or_clause:
                 provided, provided_version, op = part
-                if op != '' and op != '=':
+                if op != '' and op != '=':  # pragma: no cover
                     msg = "Ignoring invalid provides in %s: %s (%s %s)" % (str(pkg_id), provided, op, provided_version)
                     self.log(msg, type='W')
                     continue
@@ -2645,7 +2645,7 @@ class Britney(object):
         cached_nuninst = self.nuninst_orig
         self._inst_tester.compute_testing_installability()
         computed_nuninst = self.get_nuninst(build=True)
-        if cached_nuninst != computed_nuninst:
+        if cached_nuninst != computed_nuninst:  # pragma: no cover
             only_on_break_archs = True
             self.log("==================== NUNINST OUT OF SYNC =========================", type="E")
             for arch in self.options.architectures:

britney2/installability/builder.py

@@ -156,7 +156,7 @@ class InstallabilityTesterBuilder(object):
         Note, this method is optimised to be called at most once per
         binary.
         """
-        if binary not in self._package_table:
+        if binary not in self._package_table:  # pragma: no cover
             raise ValueError("Binary %s/%s/%s does not exist" % binary)
         rel = _RelationBuilder(self, binary)
         yield rel
@@ -231,7 +231,7 @@ class InstallabilityTesterBuilder(object):
         #
         # At the same time, intern the rdep sets
         for pkg in reverse_package_table:
-            if pkg not in package_table:
+            if pkg not in package_table:  # pragma: no cover
                 raise RuntimeError("%s/%s/%s referenced but not added!" % pkg)
             deps, con = package_table[pkg]
             rdeps, rcon, rdep_relations = reverse_package_table[pkg]

britney2/installability/solver.py

@@ -63,7 +63,7 @@ class InstallabilitySolver(InstallabilityTester):
         going_in = set()
         debug_solver = 0
 
-        try:
+        try:  # pragma: no cover
             debug_solver = int(os.environ.get('BRITNEY_DEBUG', '0'))
         except:
             pass
@@ -80,7 +80,7 @@ class InstallabilitySolver(InstallabilityTester):
             for r in rms:
                 ptable[r] = key
 
-        if debug_solver > 1:
+        if debug_solver > 1:  # pragma: no cover
             self._dump_groups(groups)
 
         # This large loop will add ordering constrains on each "item"
@@ -107,7 +107,7 @@ class InstallabilitySolver(InstallabilityTester):
                     if other == key:
                         # "Self-conflicts" => ignore
                         continue
-                    if debug_solver and other not in order[key]['before']:
+                    if debug_solver and other not in order[key]['before']:  # pragma: no cover
                         print("N: Conflict induced order: %s before %s" % (key, other))
                     order[key]['before'].add(other)
                     order[other]['after'].add(key)
@@ -126,7 +126,7 @@ class InstallabilitySolver(InstallabilityTester):
                             if other == key:
                                 # "Self-dependency" => ignore
                                 continue
-                            if debug_solver and other not in order[key]['after']:
+                            if debug_solver and other not in order[key]['after']:  # pragma: no cover
                                 print("N: Removal induced order: %s before %s" % (key, other))
                             order[key]['after'].add(other)
                             order[other]['before'].add(key)
@@ -163,13 +163,13 @@ class InstallabilitySolver(InstallabilityTester):
                             other_rms.add(other)
 
                     for other in (other_adds - other_rms):
-                        if debug_solver and other != key and other not in order[key]['after']:
+                        if debug_solver and other != key and other not in order[key]['after']:  # pragma: no cover
                             print("N: Dependency induced order (add): %s before %s" % (key, other))
                         order[key]['after'].add(other)
                         order[other]['before'].add(key)
 
                     for other in (other_rms - other_adds):
-                        if debug_solver and other != key and other not in order[key]['before']:
+                        if debug_solver and other != key and other not in order[key]['before']:  # pragma: no cover
                             print("N: Dependency induced order (remove): %s before %s" % (key, other))
                         order[key]['before'].add(other)
                         order[other]['after'].add(key)
@@ -209,7 +209,7 @@ class InstallabilitySolver(InstallabilityTester):
                     so_after.update(order[n]['after'])
                     merged[n] = scc_id
                     del order[n]
-                if debug_solver:
+                if debug_solver:  # pragma: no cover
                     print("N: SCC: %s -- %s" % (scc_id, str(sorted(com))))
 
         for com in comps:
@@ -223,32 +223,31 @@ class InstallabilitySolver(InstallabilityTester):
             order[node]['before'] = nbefore
             order[node]['after'] = nafter
 
-
+        if debug_solver:  # pragma: no cover
-        if debug_solver:
             print("N: -- PARTIAL ORDER --")
 
         initial_round = []
         for com in sorted(order):
-            if debug_solver and order[com]['before']:
+            if debug_solver and order[com]['before']:  # pragma: no cover
                 print("N: %s <= %s" % (com, str(sorted(order[com]['before']))))
             if not order[com]['after']:
                 # This component can be scheduled immediately, add it
                 # to the queue
                 initial_round.append(com)
-            elif debug_solver:
+            elif debug_solver:  # pragma: no cover
                 print("N: %s >= %s" % (com, str(sorted(order[com]['after']))))
 
         queue.extend(sorted(initial_round, key=len))
         del initial_round
 
-        if debug_solver:
+        if debug_solver:  # pragma: no cover
             print("N: -- END PARTIAL ORDER --")
             print("N: -- LINEARIZED ORDER --")
 
         for cur in iter_except(queue.popleft, IndexError):
             if order[cur]['after'] <= emitted and cur not in emitted:
                 # This item is ready to be emitted right now
-                if debug_solver:
+                if debug_solver:  # pragma: no cover
                     print("N: %s -- %s" % (cur, sorted(scc[cur])))
                 emitted.add(cur)
                 result.append([key2item[x] for x in scc[cur]])
@@ -259,12 +258,11 @@ class InstallabilitySolver(InstallabilityTester):
                     # - else, it will be dropped and re-added later.
                     queue.extend(sorted(order[cur]['before'] - emitted, key=len))
 
-        if debug_solver:
+        if debug_solver:  # pragma: no cover
             print("N: -- END LINEARIZED ORDER --")
 
         return result
 
-
     def _compute_scc(self, order, ptable):
         """
         Tarjan's algorithm and topological sorting implementation in Python
@@ -306,7 +304,7 @@ class InstallabilitySolver(InstallabilityTester):
 
         return result
 
-    def _dump_groups(self, groups):
+    def _dump_groups(self, groups):  # pragma: no cover
         print("N: === Groups ===")
         for (item, adds, rms) in groups:
             print("N: %s =>  A: %s, R: %s" % (str(item), str(adds), str(rms)))

britney2/installability/tester.py

@@ -168,7 +168,7 @@ class InstallabilityTester(object):
         :param pkg_id The id of the package
         """
 
-        if pkg_id not in self._universe:
+        if pkg_id not in self._universe:  # pragma: no cover
             raise KeyError(str(pkg_id))
 
         if pkg_id in self._broken:
@@ -197,7 +197,7 @@ class InstallabilityTester(object):
         KeyError.
         """
 
-        if pkg_id not in self._universe:
+        if pkg_id not in self._universe:  # pragma: no cover
             raise KeyError(str(pkg_id))
 
         self._cache_broken.discard(pkg_id)
@@ -231,7 +231,7 @@ class InstallabilityTester(object):
 
         self._stats.is_installable_calls += 1
 
-        if pkg_id not in self._universe:
+        if pkg_id not in self._universe:  # pragma: no cover
             raise KeyError(str(pkg_id))
 
         if pkg_id not in self._testing or pkg_id in self._broken:

britney2/policies/policy.py

@@ -69,14 +69,14 @@ class BasePolicy(object):
         if self.options.verbose or type in ("E", "W"):
             print("%s: [%s] - %s" % (type, time.asctime(), msg))
 
-    def register_hints(self, hint_parser):
+    def register_hints(self, hint_parser):  # pragma: no cover
         """Register new hints that this policy accepts
 
         :param hint_parser: An instance of HintParser (see HintParser.register_hint_type)
         """
         pass
 
-    def initialise(self, britney):
+    def initialise(self, britney):  # pragma: no cover
         """Called once to make the policy initialise any data structures
 
         This is useful for e.g. parsing files or other "heavy do-once" work.
@@ -85,7 +85,7 @@ class BasePolicy(object):
         """
         pass
 
-    def save_state(self, britney):
+    def save_state(self, britney):  # pragma: no cover
         """Called once at the end of the run to make the policy save any persistent data
 
         Note this will *not* be called for "dry-runs" as such runs should not change
@@ -103,7 +103,7 @@ class BasePolicy(object):
         return self.apply_policy_impl(pinfo, suite, source_name, source_data_tdist, source_data_srcdist, excuse)
 
     @abstractmethod
-    def apply_policy_impl(self, policy_info, suite, source_name, source_data_tdist, source_data_srcdist, excuse):
+    def apply_policy_impl(self, policy_info, suite, source_name, source_data_tdist, source_data_srcdist, excuse):  # pragma: no cover
         """Apply a policy on a given source migration
 
         Britney will call this method on a given source package, when
@@ -208,7 +208,7 @@ class AgePolicy(BasePolicy):
     def __init__(self, options, suite_info, mindays):
         super().__init__('age', options, suite_info, {'unstable'})
         self._min_days = mindays
-        if options.default_urgency not in mindays:
+        if options.default_urgency not in mindays:  # pragma: no cover
             raise ValueError("Missing age-requirement for default urgency (MINDAYS_%s)" % options.default_urgency)
         self._min_days_default = mindays[options.default_urgency]
         # britney's "day" begins at 3pm

britney2/utils.py

@@ -675,6 +675,6 @@ def read_release_file(suite_dir):
     with open(release_file) as fd:
         tag_file = iter(apt_pkg.TagFile(fd))
         result = next(tag_file)
-        if next(tag_file, None) is not None:
+        if next(tag_file, None) is not None:  # pragma: no cover
             raise TypeError("%s has more than one paragraph" % release_file)
     return result