Add python coverage module to third_party

third_party/pycoverage/coverage/results.py

Index: third_party/pycoverage/coverage/results.py
diff --git a/third_party/pycoverage/coverage/results.py b/third_party/pycoverage/coverage/results.py
new file mode 100644
index 0000000000000000000000000000000000000000..db6df0d30b7e389319de83ebaaf11fa4c7806e22
--- /dev/null
+++ b/third_party/pycoverage/coverage/results.py
@@ -0,0 +1,286 @@
+"""Results of coverage measurement."""
+
+import os
+
+from coverage.backward import iitems, set, sorted       # pylint: disable=W0622
+from coverage.misc import format_lines, join_regex, NoSource
+from coverage.parser import CodeParser
+
+
+class Analysis(object):
+    """The results of analyzing a code unit."""
+
+    def __init__(self, cov, code_unit):
+        self.coverage = cov
+        self.code_unit = code_unit
+
+        self.filename = self.code_unit.filename
+        actual_filename, source = self.find_source(self.filename)
+
+        self.parser = CodeParser(
+            text=source, filename=actual_filename,
+            exclude=self.coverage._exclude_regex('exclude')
+            )
+        self.statements, self.excluded = self.parser.parse_source()
+
+        # Identify missing statements.
+        executed = self.coverage.data.executed_lines(self.filename)
+        exec1 = self.parser.first_lines(executed)
+        self.missing = self.statements - exec1
+
+        if self.coverage.data.has_arcs():
+            self.no_branch = self.parser.lines_matching(
+                join_regex(self.coverage.config.partial_list),
+                join_regex(self.coverage.config.partial_always_list)
+                )
+            n_branches = self.total_branches()
+            mba = self.missing_branch_arcs()
+            n_partial_branches = sum(
+                [len(v) for k,v in iitems(mba) if k not in self.missing]
+                )
+            n_missing_branches = sum([len(v) for k,v in iitems(mba)])
+        else:
+            n_branches = n_partial_branches = n_missing_branches = 0
+            self.no_branch = set()
+
+        self.numbers = Numbers(
+            n_files=1,
+            n_statements=len(self.statements),
+            n_excluded=len(self.excluded),
+            n_missing=len(self.missing),
+            n_branches=n_branches,
+            n_partial_branches=n_partial_branches,
+            n_missing_branches=n_missing_branches,
+            )
+
+    def find_source(self, filename):
+        """Find the source for `filename`.
+
+        Returns two values: the actual filename, and the source.
+
+        The source returned depends on which of these cases holds:
+
+            * The filename seems to be a non-source file: returns None
+
+            * The filename is a source file, and actually exists: returns None.
+
+            * The filename is a source file, and is in a zip file or egg:
+              returns the source.
+
+            * The filename is a source file, but couldn't be found: raises
+              `NoSource`.
+
+        """
+        source = None
+
+        base, ext = os.path.splitext(filename)
+        TRY_EXTS = {
+            '.py':  ['.py', '.pyw'],
+            '.pyw': ['.pyw'],
+        }
+        try_exts = TRY_EXTS.get(ext)
+        if not try_exts:
+            return filename, None
+
+        for try_ext in try_exts:
+            try_filename = base + try_ext
+            if os.path.exists(try_filename):
+                return try_filename, None
+            source = self.coverage.file_locator.get_zip_data(try_filename)
+            if source:
+                return try_filename, source
+        raise NoSource("No source for code: '%s'" % filename)
+
+    def missing_formatted(self):
+        """The missing line numbers, formatted nicely.
+
+        Returns a string like "1-2, 5-11, 13-14".
+
+        """
+        return format_lines(self.statements, self.missing)
+
+    def has_arcs(self):
+        """Were arcs measured in this result?"""
+        return self.coverage.data.has_arcs()
+
+    def arc_possibilities(self):
+        """Returns a sorted list of the arcs in the code."""
+        arcs = self.parser.arcs()
+        return arcs
+
+    def arcs_executed(self):
+        """Returns a sorted list of the arcs actually executed in the code."""
+        executed = self.coverage.data.executed_arcs(self.filename)
+        m2fl = self.parser.first_line
+        executed = [(m2fl(l1), m2fl(l2)) for (l1,l2) in executed]
+        return sorted(executed)
+
+    def arcs_missing(self):
+        """Returns a sorted list of the arcs in the code not executed."""
+        possible = self.arc_possibilities()
+        executed = self.arcs_executed()
+        missing = [
+            p for p in possible
+                if p not in executed
+                    and p[0] not in self.no_branch
+            ]
+        return sorted(missing)
+
+    def arcs_unpredicted(self):
+        """Returns a sorted list of the executed arcs missing from the code."""
+        possible = self.arc_possibilities()
+        executed = self.arcs_executed()
+        # Exclude arcs here which connect a line to itself.  They can occur
+        # in executed data in some cases.  This is where they can cause
+        # trouble, and here is where it's the least burden to remove them.
+        unpredicted = [
+            e for e in executed
+                if e not in possible
+                    and e[0] != e[1]
+            ]
+        return sorted(unpredicted)
+
+    def branch_lines(self):
+        """Returns a list of line numbers that have more than one exit."""
+        exit_counts = self.parser.exit_counts()
+        return [l1 for l1,count in iitems(exit_counts) if count > 1]
+
+    def total_branches(self):
+        """How many total branches are there?"""
+        exit_counts = self.parser.exit_counts()
+        return sum([count for count in exit_counts.values() if count > 1])
+
+    def missing_branch_arcs(self):
+        """Return arcs that weren't executed from branch lines.
+
+        Returns {l1:[l2a,l2b,...], ...}
+
+        """
+        missing = self.arcs_missing()
+        branch_lines = set(self.branch_lines())
+        mba = {}
+        for l1, l2 in missing:
+            if l1 in branch_lines:
+                if l1 not in mba:
+                    mba[l1] = []
+                mba[l1].append(l2)
+        return mba
+
+    def branch_stats(self):
+        """Get stats about branches.
+
+        Returns a dict mapping line numbers to a tuple:
+        (total_exits, taken_exits).
+        """
+
+        exit_counts = self.parser.exit_counts()
+        missing_arcs = self.missing_branch_arcs()
+        stats = {}
+        for lnum in self.branch_lines():
+            exits = exit_counts[lnum]
+            try:
+                missing = len(missing_arcs[lnum])
+            except KeyError:
+                missing = 0
+            stats[lnum] = (exits, exits - missing)
+        return stats
+
+
+class Numbers(object):
+    """The numerical results of measuring coverage.
+
+    This holds the basic statistics from `Analysis`, and is used to roll
+    up statistics across files.
+
+    """
+    # A global to determine the precision on coverage percentages, the number
+    # of decimal places.
+    _precision = 0
+    _near0 = 1.0              # These will change when _precision is changed.
+    _near100 = 99.0
+
+    def __init__(self, n_files=0, n_statements=0, n_excluded=0, n_missing=0,
+                    n_branches=0, n_partial_branches=0, n_missing_branches=0
+                    ):
+        self.n_files = n_files
+        self.n_statements = n_statements
+        self.n_excluded = n_excluded
+        self.n_missing = n_missing
+        self.n_branches = n_branches
+        self.n_partial_branches = n_partial_branches
+        self.n_missing_branches = n_missing_branches
+
+    def set_precision(cls, precision):
+        """Set the number of decimal places used to report percentages."""
+        assert 0 <= precision < 10
+        cls._precision = precision
+        cls._near0 = 1.0 / 10**precision
+        cls._near100 = 100.0 - cls._near0
+    set_precision = classmethod(set_precision)
+
+    def _get_n_executed(self):
+        """Returns the number of executed statements."""
+        return self.n_statements - self.n_missing
+    n_executed = property(_get_n_executed)
+
+    def _get_n_executed_branches(self):
+        """Returns the number of executed branches."""
+        return self.n_branches - self.n_missing_branches
+    n_executed_branches = property(_get_n_executed_branches)
+
+    def _get_pc_covered(self):
+        """Returns a single percentage value for coverage."""
+        if self.n_statements > 0:
+            pc_cov = (100.0 * (self.n_executed + self.n_executed_branches) /
+                        (self.n_statements + self.n_branches))
+        else:
+            pc_cov = 100.0
+        return pc_cov
+    pc_covered = property(_get_pc_covered)
+
+    def _get_pc_covered_str(self):
+        """Returns the percent covered, as a string, without a percent sign.
+
+        Note that "0" is only returned when the value is truly zero, and "100"
+        is only returned when the value is truly 100.  Rounding can never
+        result in either "0" or "100".
+
+        """
+        pc = self.pc_covered
+        if 0 < pc < self._near0:
+            pc = self._near0
+        elif self._near100 < pc < 100:
+            pc = self._near100
+        else:
+            pc = round(pc, self._precision)
+        return "%.*f" % (self._precision, pc)
+    pc_covered_str = property(_get_pc_covered_str)
+
+    def pc_str_width(cls):
+        """How many characters wide can pc_covered_str be?"""
+        width = 3   # "100"
+        if cls._precision > 0:
+            width += 1 + cls._precision
+        return width
+    pc_str_width = classmethod(pc_str_width)
+
+    def __add__(self, other):
+        nums = Numbers()
+        nums.n_files = self.n_files + other.n_files
+        nums.n_statements = self.n_statements + other.n_statements
+        nums.n_excluded = self.n_excluded + other.n_excluded
+        nums.n_missing = self.n_missing + other.n_missing
+        nums.n_branches = self.n_branches + other.n_branches
+        nums.n_partial_branches = (
+            self.n_partial_branches + other.n_partial_branches
+            )
+        nums.n_missing_branches = (
+            self.n_missing_branches + other.n_missing_branches
+            )
+        return nums
+
+    def __radd__(self, other):
+        # Implementing 0+Numbers allows us to sum() a list of Numbers.
+        if other == 0:
+            return self
+        return NotImplemented