fix: Editeur Excalidraw - diagramme vide (CSS + appState) et auto-save pendant l'edition (BUG-064, BUG-065)

tests/test_security_hardening.py

@@ -317,3 +317,25 @@ class TestTokenInvalidation:
             "/api/auth/me", headers={"Authorization": f"Bearer {token}"}
         )
         assert me.status_code == 401
+
+
+# ═══════════════════════════════════════════════════════════════════
+# BUG-064 — Excalidraw editor stylesheet (esm.sh) must pass CSP
+# ═══════════════════════════════════════════════════════════════════
+
+class TestCspExcalidrawStylesheet:
+    def test_style_src_allows_esm_sh(self, client):
+        """The Excalidraw editor loads its stylesheet from esm.sh.
+
+        Without this directive the CSS is blocked, the editor is unstyled and
+        its container enters a resize feedback loop up to the 2^25 canvas cap,
+        leaving the scene blank (BUG-064).
+        """
+        resp = client.get("/api/health")
+        csp = resp.headers.get("content-security-policy", "")
+        style_src = next(
+            (d.strip() for d in csp.split(";") if d.strip().startswith("style-src")),
+            "",
+        )
+        assert style_src, "CSP style-src directive not found"
+        assert "https://esm.sh" in style_src