fix(scrape): keep C++, C# and C job titles distinct in dedup and keys (#830)

norm() dropped "+" and "#", so "C++ Developer", "C# Developer" and
"C Developer" at one company normalized alike: /scrape counted a new
posting as already seen and /rank excluded it once the user had applied
to the other. slugify() did the same for canonical keys, so keep both
characters (spelled out as plus/sharp in keys). Keys stored under the old
rule are re-keyed by job_key.py --audit --migrate; the store collision
error now says so.

tests/test_scrape_state.py

@@ -70,6 +70,18 @@ class ScrapeStateTests(unittest.TestCase):
         self.assertEqual(stored["legacy_key"], old["legacy_key"])
         self.assertEqual(stored["fresh_builder"], fresh)
 
+    def test_c_sharp_and_c_plus_plus_titles_are_different_postings(self):
+        base = {
+            "company": "Acme", "first_seen": "2026-10-21", "posted_date": None, "deadline": None,
+            "fit": "high", "status": "new", "portal": "example-search", "source": "cli",
+        }
+        cpp = {**base, "title": "C++ Developer", "url": "https://jobs.test/1111111"}
+        self.assertEqual(len(self.run_tool("store", [cpp])["added"]), 1)
+        csharp = {**base, "title": "C# Developer", "url": "https://jobs.test/2222222"}
+        out = self.run_tool("candidates", [csharp])
+        self.assertEqual(out["selected"], [csharp])
+        self.assertEqual(len(self.run_tool("store", [csharp])["added"]), 1)
+
     def test_store_creates_missing_history_and_rejects_partial_entries_without_writing(self):
         good = {
             "title": "Builder", "company": "Fresh", "url": "https://jobs.test/fresh",

tools/job_key.py

@@ -105,6 +105,8 @@ def slugify(text: str) -> str:
     decomposed = unicodedata.normalize("NFKD", str(text))
     folded = decomposed.translate(_LATIN_FOLD_TABLE)
     ascii_only = folded.encode("ascii", "ignore").decode("ascii")
+    # Spell out "+" and "#" so "C++", "C#" and "C" titles keep distinct keys.
+    ascii_only = ascii_only.replace("+", "plus").replace("#", "sharp")
     return _NON_SLUG.sub("-", ascii_only.lower()).strip("-")
 
 

tools/rank_state.py

@@ -146,7 +146,8 @@ def norm(text) -> str:
     # Combining marks can distinguish names even after NFC (e.g. Indic vowels).
     return "".join(
         char for char in text
-        if char.isalnum() or unicodedata.category(char).startswith("M")
+        # "+" and "#" carry identity: "C++", "C#" and "C" are different jobs.
+        if char.isalnum() or char in "+#" or unicodedata.category(char).startswith("M")
     )
 
 

tools/scrape_state.py

@@ -117,7 +117,10 @@ def run(args) -> int:
             raise ValueError("job has an invalid portal or source")
         key = make_key(job["company"], job["title"], job["url"])
         if key in seen:
-            raise ValueError(f"canonical key already exists for another posting: {key}")
+            raise ValueError(
+                f"canonical key already exists for another posting: {key} "
+                "(keys stored before a key-rule change: run python3 tools/job_key.py --audit --migrate)"
+            )
         seen[key] = job
     if selected:
         args.state.parent.mkdir(parents=True, exist_ok=True)