debug: dataop2 logs the actual data being added to CoverageData objects

CHANGES.rst

@@ -20,8 +20,11 @@ development at the same time, such as 4.5.x and 5.0.
 Unreleased
 ----------
 
-- Added a new :ref:`debug option <cmd_run_debug>` ``pytest`` to write the 
-  pytest test name into the debug output.
+- Added new :ref:`debug options <cmd_run_debug>`:
+
+  - ``pytest`` writes the pytest test name into the debug output.
+
+  - ``dataop2`` writes the full data being added to CoverageData objects.
 
 
 .. scriv-start-here

coverage/sqldata.py

@@ -489,6 +489,9 @@ def add_lines(self, line_data: Mapping[str, Collection[TLineNo]]) -> None:
             self._debug.write("Adding lines: %d files, %d lines total" % (
                 len(line_data), sum(len(lines) for lines in line_data.values())
             ))
+            if self._debug.should("dataop2"):
+                for filename, linenos in sorted(line_data.items()):
+                    self._debug.write(f"  {filename}: {linenos}")
         self._start_using()
         self._choose_lines_or_arcs(lines=True)
         if not line_data:
@@ -524,6 +527,9 @@ def add_arcs(self, arc_data: Mapping[str, Collection[TArc]]) -> None:
             self._debug.write("Adding arcs: %d files, %d arcs total" % (
                 len(arc_data), sum(len(arcs) for arcs in arc_data.values())
             ))
+            if self._debug.should("dataop2"):
+                for filename, arcs in sorted(arc_data.items()):
+                    self._debug.write(f"  {filename}: {arcs}")
         self._start_using()
         self._choose_lines_or_arcs(arcs=True)
         if not arc_data:

doc/cmd.rst

@@ -1022,7 +1022,10 @@ of operation to log:
 
 * ``dataio``: log when reading or writing any data file.
 
-* ``dataop``: log when data is added to the CoverageData object.
+* ``dataop``: log a summary of data being added to CoverageData objects.
+
+* ``dataop2``: when used with ``debug=dataop``, log the actual data being added
+  to CoverageData objects.
 
 * ``lock``: log operations acquiring locks in the data layer.
 

tests/test_data.py

@@ -82,7 +82,7 @@ def DebugCoverageData(*args: Any, **kwargs: Any) -> CoverageData:
     if kwargs:
         # There's no logical reason kwargs should imply sqldata debugging.
         # This is just a way to get a mix of debug options across the tests.
-        options.append("sqldata")
+        options.extend(["dataop2", "sqldata"])
     debug = DebugControlString(options=options)
     return CoverageData(*args, debug=debug, **kwargs)   # type: ignore[misc]