gh-112192: Increase the trace module coverage precision to one decimal (#126972)

Author: rruuaanng

Lib/test/test_regrtest.py

@@ -1138,7 +1138,7 @@ def test_coverage(self):
         output = self.run_tests("--coverage", test)
         self.check_executed_tests(output, [test], stats=1)
         regex = (r'lines +cov% +module +\(path\)\n'
-                 r'(?: *[0-9]+ *[0-9]{1,2}% *[^ ]+ +\([^)]+\)+)+')
+                 r'(?: *[0-9]+ *[0-9]{1,2}\.[0-9]% *[^ ]+ +\([^)]+\)+)+')
         self.check_line(output, regex)
 
     def test_wait(self):

Lib/test/test_trace.py

@@ -412,7 +412,7 @@ def test_issue9936(self):
         coverage = {}
         for line in stdout:
             lines, cov, module = line.split()[:3]
-            coverage[module] = (int(lines), int(cov[:-1]))
+            coverage[module] = (float(lines), float(cov[:-1]))
         # XXX This is needed to run regrtest.py as a script
         modname = trace._fullmodname(sys.modules[modname].__file__)
         self.assertIn(modname, coverage)
@@ -553,7 +553,7 @@ def f():
         stdout = stdout.decode()
         self.assertEqual(status, 0)
         self.assertIn('lines   cov%   module   (path)', stdout)
-        self.assertIn(f'6   100%   {modulename}   ({filename})', stdout)
+        self.assertIn(f'6   100.0%   {modulename}   ({filename})', stdout)
 
     def test_run_as_module(self):
         assert_python_ok('-m', 'trace', '-l', '--module', 'timeit', '-n', '1')

Lib/trace.py

@@ -279,14 +279,13 @@ def write_results(self, show_missing=True, summary=False, coverdir=None, *,
             n_hits, n_lines = self.write_results_file(coverpath, source,
                                                       lnotab, count, encoding)
             if summary and n_lines:
-                percent = int(100 * n_hits / n_lines)
-                sums[modulename] = n_lines, percent, modulename, filename
+                sums[modulename] = n_lines, n_hits, modulename, filename
 
         if summary and sums:
             print("lines   cov%   module   (path)")
             for m in sorted(sums):
-                n_lines, percent, modulename, filename = sums[m]
-                print("%5d   %3d%%   %s   (%s)" % sums[m])
+                n_lines, n_hits, modulename, filename = sums[m]
+                print(f"{n_lines:5d}   {n_hits/n_lines:.1%}   {modulename}   ({filename})")
 
         if self.outfile:
             # try and store counts and module info into self.outfile

Misc/NEWS.d/next/Library/2024-11-18-23-18-27.gh-issue-112192.DRdRgP.rst

@@ -0,0 +1 @@
+In the :mod:`trace` module, increase the coverage precision (``cov%``) to one decimal.