Tests for debug tracing features.

1 files changed, 88 insertions, 0 deletions

diff --git a/tests/test_debug.py b/tests/test_debug.py
index f3ae31fb..0132c1c8 100644
--- a/tests/test_debug.py
+++ b/tests/test_debug.py
@@ -1,5 +1,10 @@
 """Tests of coverage/debug.py"""
 
+import os
+import re
+
+import coverage
+from coverage.backward import StringIO
 from coverage.debug import info_formatter
 from tests.coveragetest import CoverageTest
 
@@ -23,3 +28,86 @@ class InfoFormatterTest(CoverageTest):
             '                 jkl',
             '        nothing: -none-',
         ])
+
+
+class DebugTraceTest(CoverageTest):
+    """Tests of debug output."""
+
+    def f1_debug_output(self, debug):
+        """Runs some code with `debug` option, returns the debug output."""
+        # Make code to run.
+        self.make_file("f1.py", """\
+            def f1(x):
+                return x+1
+
+            for i in range(5):
+                f1(i)
+            """)
+
+        debug_out = StringIO()
+        cov = coverage.coverage(debug=debug, debug_file=debug_out)
+        self.start_import_stop(cov, "f1")
+
+        out_lines = debug_out.getvalue().splitlines()
+        return out_lines
+
+    def test_debug_no_trace(self):
+        out_lines = self.f1_debug_output([])
+
+        # We should have no output at all.
+        self.assertFalse(out_lines)
+
+    def test_debug_trace(self):
+        out_lines = self.f1_debug_output(["trace"])
+
+        # We should have a line like "Tracing 'f1.py'"
+        self.assertIn("Tracing 'f1.py'", out_lines)
+
+        # We should lines like "Not tracing 'collector.py'..."
+        coverage_lines = lines_matching(
+            out_lines,
+            r"^Not tracing .*: is part of coverage.py$"
+            )
+        self.assertTrue(coverage_lines)
+
+    def test_debug_trace_pid(self):
+        out_lines = self.f1_debug_output(["trace", "pid"])
+
+        # Now our lines are always prefixed with the process id.
+        pid_prefix = "^pid %5d: " % os.getpid()
+        pid_lines = lines_matching(out_lines, pid_prefix)
+        self.assertEqual(pid_lines, out_lines)
+
+        # We still have some tracing, and some not tracing.
+        self.assertTrue(lines_matching(out_lines, pid_prefix + "Tracing "))
+        self.assertTrue(lines_matching(out_lines, pid_prefix + "Not tracing "))
+
+    def test_debug_config(self):
+        out_lines = self.f1_debug_output(["config"])
+
+        labels = """
+            attempted_config_files branch config_files cover_pylib data_file
+            debug exclude_list extra_css html_dir html_title ignore_errors
+            include omit parallel partial_always_list partial_list paths
+            precision show_missing source timid xml_output
+            """.split()
+        for label in labels:
+            label_pat = r"^\s*%s: " % label
+            self.assertEqual(len(lines_matching(out_lines, label_pat)), 1)
+
+    def test_debug_sys(self):
+        out_lines = self.f1_debug_output(["sys"])
+
+        labels = """
+            version coverage cover_dir pylib_dirs tracer config_files
+            configs_read data_path python platform implementation executable
+            cwd path environment command_line cover_match pylib_match
+            """.split()
+        for label in labels:
+            label_pat = r"^\s*%s: " % label
+            self.assertEqual(len(lines_matching(out_lines, label_pat)), 1)
+
+
+def lines_matching(lines, pat):
+    """Gives the list of lines from `lines` that match `pat`."""
+    return [l for l in lines if re.search(pat, l)]