LinkedIn Username Validation

user_scanner/social/linkedin.py

@@ -0,0 +1,69 @@
+from user_scanner.core.orchestrator import generic_validate
+from user_scanner.core.result import Result
+
+
+def validate_linkedin(user: str) -> Result:
+    """
+    LinkedIn username validator.
+
+    Notes:
+    - LinkedIn aggressively blocks automated traffic.
+    - This validator is intentionally conservative.
+    - Blocked responses are treated as 'unknown'.
+    """
+
+    url = f"https://www.linkedin.com/in/{user}/"
+
+    headers = {
+        "User-Agent": (
+            "Mozilla/5.0 (X11; Linux x86_64) "
+            "AppleWebKit/537.36 (KHTML, like Gecko) "
+            "Chrome/120.0.0.0 Safari/537.36"
+        ),
+        "Accept-Language": "en-US,en;q=0.9",
+        'Accept': "text/html,application/xhtml+xml,application/xml;q=0.9",
+        'Accept-Encoding': "gzip, deflate, br, zstd",
+        'Upgrade-Insecure-Requests': "1",
+    }
+
+    NOT_FOUND_PHRASES = (
+        "This page doesn’t exist",
+        "This profile is not available",
+        "Page not found",
+    )
+
+    LOGIN_HINTS = (
+        "Sign in to LinkedIn",
+        "/login",
+        "/checkpoint",
+    )
+
+    def process(response):
+        status = response.status_code
+        text = response.text or ""
+
+        if status in (403, 429, 999):
+            return Result.error("blocked (linkedin)")
+
+        if status in (301, 302, 303):
+            return Result.taken()
+
+        if status == 200:
+            if any(hint in text for hint in LOGIN_HINTS):
+                return Result.taken()
+
+            if any(p in text for p in NOT_FOUND_PHRASES):
+                return Result.available()
+
+            return Result.taken()
+
+        if status == 404:
+            return Result.available()
+        return Result.error(f"unexpected status {status}")
+
+    return generic_validate(
+        url,
+        process,
+        headers=headers,
+        follow_redirects=False,
+    )