Merge pull request #9699 from github/redsun82/swift-stop-stub-reverts

Swift: yet another fix to stub revert prevention

Author: redsun82

swift/codegen/generators/qlgen.py

@@ -2,8 +2,10 @@
 
 import logging
 import pathlib
+import re
 import subprocess
 import typing
+import itertools
 
 import inflection
 
@@ -93,7 +95,10 @@ def get_classes_used_by(cls: ql.Class):
     return sorted(set(t for t in get_types_used_by(cls) if t[0].isupper()))
 
 
-def _is_generated_stub(file, check_modification=False):
+_generated_stub_re = re.compile(r"private import .*\n\nclass \w+ extends \w+ \{[ \n]\}", re.MULTILINE)
+
+
+def _is_generated_stub(file):
     with open(file) as contents:
         for line in contents:
             if not line.startswith("// generated"):
@@ -102,12 +107,12 @@ def _is_generated_stub(file, check_modification=False):
         else:
             # no lines
             return False
-        if check_modification:
-            # one line already read, if we can read 5 other we are past the normal stub generation
-            line_threshold = 5
-            if sum(1 for _ in zip(range(line_threshold), contents)) == line_threshold:
-                raise ModifiedStubMarkedAsGeneratedError(
-                    f"{file.name} stub was modified but is still marked as generated")
+        # one line already read, if we can read 5 other we are past the normal stub generation
+        line_threshold = 5
+        first_lines = list(itertools.islice(contents, line_threshold))
+        if len(first_lines) == line_threshold or not _generated_stub_re.match("".join(first_lines)):
+            raise ModifiedStubMarkedAsGeneratedError(
+                f"{file.name} stub was modified but is still marked as generated")
         return True
 
 
@@ -157,8 +162,9 @@ def generate(opts, renderer):
     stub_out = opts.ql_stub_output
     test_out = opts.ql_test_output
     missing_test_source_filename = "MISSING_SOURCE.txt"
+
     existing = {q for q in out.rglob("*.qll")}
-    existing |= {q for q in stub_out.rglob("*.qll") if _is_generated_stub(q, check_modification=True)}
+    existing |= {q for q in stub_out.rglob("*.qll") if _is_generated_stub(q)}
     existing |= {q for q in test_out.rglob("*.ql")}
     existing |= {q for q in test_out.rglob(missing_test_source_filename)}
 

swift/codegen/test/test_qlgen.py

@@ -366,7 +366,7 @@ def test_non_empty_cleanup(opts, generate, renderer):
     test_c = opts.ql_test_output / "B.txt"
     write(ql_a)
     write(ql_b)
-    write(stub_a, "// generated\nfoo\n")
+    write(stub_a, "// generated\nprivate import bla\n\nclass foo extends bar {\n}\n")
     write(stub_b, "bar\n")
     write(test_a)
     write(test_b)
@@ -378,7 +378,15 @@ def test_non_empty_cleanup(opts, generate, renderer):
 
 def test_modified_stub_still_generated(qlgen_opts, renderer):
     stub = qlgen_opts.ql_stub_output / "A.qll"
-    write(stub, "// generated\nprivate import foo\n\nclass Bar extends BarBase {\n  int x() { none() }\n}\n")
+    write(stub, "// generated\nprivate import bla\n\nclass foo extends bar, baz {\n}\n")
+    with pytest.raises(qlgen.ModifiedStubMarkedAsGeneratedError):
+        run_generation(qlgen.generate, qlgen_opts, renderer)
+
+
+def test_extended_stub_still_generated(qlgen_opts, renderer):
+    stub = qlgen_opts.ql_stub_output / "A.qll"
+    write(stub,
+          "// generated\nprivate import bla\n\nclass foo extends bar {\n}\n\nclass other {\n  other() { none() }\n}")
     with pytest.raises(qlgen.ModifiedStubMarkedAsGeneratedError):
         run_generation(qlgen.generate, qlgen_opts, renderer)