Revise lcovreport.lcov_arcs using the new arc_description API.

Doesn’t quite work yet, see discussion in #1850.
nedbat · Sep 24, 2024 · d767721 · d767721
1 parent 228854a
commit d767721
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Showing 2 changed files with 35 additions and 39 deletions.
diff --git a/coverage/lcovreport.py b/coverage/lcovreport.py
@@ -96,6 +96,7 @@ def lcov_functions(
 
 
 def lcov_arcs(
+    fr: FileReporter,
     analysis: Analysis,
     lines: list[int],
     outfile: IO[str],
@@ -116,39 +117,34 @@ def lcov_arcs(
 
         if taken == 0:
             # When _none_ of the out arcs from 'line' were executed,
-            # this probably means means 'line' was never executed at all.
+            # this probably means 'line' was never executed at all.
             # Cross-check with the line stats.
             assert len(executed_arcs[line]) == 0
-            if line in analysis.missing:
-                hit = "-" # indeed, never reached
-            else:
-                hit = "0" # I am not prepared to swear this is impossible
+            assert line in analysis.missing
             destinations = [
-                (int(dst < 0), abs(dst), hit) for dst in missing_arcs[line]
+                (dst, "-") for dst in missing_arcs[line]
             ]
         else:
             # Q: can we get counts of the number of times each arc was executed?
             # branch_stats has "total" and "taken" counts for each branch,
             # but it doesn't have "taken" broken down by destination.
             destinations = [
-                (int(dst < 0), abs(dst), "1") for dst in executed_arcs[line]
+                (dst, "1") for dst in executed_arcs[line]
             ]
             destinations.extend(
-                (int(dst < 0), abs(dst), "0") for dst in missing_arcs[line]
+                (dst, "0") for dst in missing_arcs[line]
             )
 
-        destinations.sort()
-        n_exits = sum(
-            1 for is_exit, _, _ in destinations if is_exit
-        )
-        for is_exit, dst, hit in destinations:
-            if is_exit:
-                if n_exits == 1:
-                    branch = "to exit"
-                else:
-                    branch = f"to exit {dst}"
-            else:
-                branch = f"to line {dst}"
+        # Sort exit arcs after normal arcs.  Exit arcs typically come from
+        # an if statement, at the end of a function, with no else clause.
+        # This structure reads like you're jumping to the end of the function
+        # when the conditional expression is false, so it should be presented
+        # as the second alternative for the branch, after the alternative that
+        # enters the if clause.
+        destinations.sort(key=lambda d: (d[0] < 0, d))
+
+        for dst, hit in destinations:
+            branch = fr.arc_description(line, dst)
             outfile.write(f"BRDA:{line},0,{branch},{hit}\n")
 
     # Summary of the branch coverage.
@@ -221,6 +217,6 @@ def lcov_file(
         lcov_lines(analysis, lines, source_lines, outfile)
         lcov_functions(fr, analysis, outfile)
         if analysis.has_arcs:
-            lcov_arcs(analysis, lines, outfile)
+            lcov_arcs(fr, analysis, lines, outfile)
 
         outfile.write("end_of_record\n")
diff --git a/tests/test_lcov.py b/tests/test_lcov.py
@@ -209,8 +209,8 @@ def is_it_x(x):
                 FNH:0
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,-
-                BRDA:2,0,to line 5,-
+                BRDA:2,0,jump to line 3,-
+                BRDA:2,0,jump to line 5,-
                 BRF:2
                 BRH:0
                 end_of_record
@@ -264,8 +264,8 @@ def test_is_it_x(self):
                 FNH:0
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,-
-                BRDA:2,0,to line 5,-
+                BRDA:2,0,jump to line 3,-
+                BRDA:2,0,jump to line 5,-
                 BRF:2
                 BRH:0
                 end_of_record
@@ -315,8 +315,8 @@ def test_half_covered_branch(self) -> None:
             DA:6,0
             LF:4
             LH:3
-            BRDA:3,0,to line 4,1
-            BRDA:3,0,to line 6,0
+            BRDA:3,0,jump to line 4,1
+            BRDA:3,0,jump to line 6,0
             BRF:2
             BRH:1
             end_of_record
@@ -383,8 +383,8 @@ def test_excluded_lines(self) -> None:
             DA:6,1
             LF:4
             LH:3
-            BRDA:3,0,to line 4,0
-            BRDA:3,0,to line 6,1
+            BRDA:3,0,jump to line 4,0
+            BRDA:3,0,jump to line 6,1
             BRF:2
             BRH:1
             end_of_record
@@ -425,8 +425,8 @@ def foo(a):
                 FNH:1
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,1
-                BRDA:2,0,to exit,1
+                BRDA:2,0,jump to line 3,1
+                BRDA:2,0,return from function 'foo',1
                 BRF:2
                 BRH:2
                 end_of_record
@@ -468,8 +468,8 @@ def foo(a):
                 FNH:1
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,1
-                BRDA:2,0,to exit,1
+                BRDA:2,0,jump to line 3,1
+                BRDA:2,0,return from function 'foo',1
                 BRF:2
                 BRH:2
                 end_of_record
@@ -507,8 +507,8 @@ def foo(a):
                 FNH:1
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,0
-                BRDA:2,0,to exit,1
+                BRDA:2,0,jump to line 3,0
+                BRDA:2,0,return from function 'foo',1
                 BRF:2
                 BRH:1
                 end_of_record
@@ -546,8 +546,8 @@ def foo(a):
                 FNH:1
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,1
-                BRDA:2,0,to exit,0
+                BRDA:2,0,jump to line 3,1
+                BRDA:2,0,return from function 'foo',0
                 BRF:2
                 BRH:1
                 end_of_record
@@ -581,8 +581,8 @@ def foo(a):
                 FNH:0
                 """),
             textwrap.dedent("""\
-                BRDA:2,0,to line 3,-
-                BRDA:2,0,to exit,-
+                BRDA:2,0,jump to line 3,-
+                BRDA:2,0,return from function 'foo',-
                 BRF:2
                 BRH:0
                 end_of_record