fix: skip unusable provider names, name the split ceiling

A provider name containing a colon builds ids that split back to a
different provider, and an empty name builds ':model'; both routed to the
local router under a nonsense name with no error, so parse() now skips
them. split() stays non-injective by design, since bare local ids are the
premise here, so the residual risk is recorded as a ponytail comment with
its upgrade path rather than hidden. Also pin the trailing-colon form Task
9 relies on, and the empty-needle filter, which were correct but untested.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/test_llamachat.py b/test_llamachat.py
index 5f6bad6..8b722ae 100755
--- a/test_llamachat.py
+++ b/test_llamachat.py
@@ -987,7 +987,18 @@ def test_provider_parsing():
                              "filter": {"a": 1}}}}
     )
     assert odd["n"].filter == ["5"]
-    assert odd["d"].filter == ["{'a': 1}"]
+    # The invariant is that the dict was wrapped whole, not iterated into its
+    # keys. Asserting that rather than its repr, which is not ours to pin.
+    assert odd["d"].filter != ["a"] and len(odd["d"].filter) == 1
+
+    # A colon in a provider name would make every id built from it ambiguous,
+    # so such a provider is skipped rather than silently routed to local.
+    colonic = providers.parse(
+        {"providers": {"local": {"base_url": "http://x.example.org"},
+                       "a:b": {"base_url": "http://y.example.org"},
+                       "": {"base_url": "http://z.example.org"}}}
+    )
+    assert set(colonic) == {"local"}
     print("ok  provider config parsing")
 
 
@@ -1023,6 +1034,8 @@ def test_model_ids_and_filtering():
     assert providers.split("weird:name", table) == ("local", "weird:name")
     # Only the first colon splits.
     assert providers.split("together:a:b", table) == ("together", "a:b")
+    # Task 9 addresses a provider itself with an empty model name.
+    assert providers.split("together:", table) == ("together", "")
 
     # Filtering is case-insensitive substring, any match wins.
     listed = [
@@ -1044,6 +1057,10 @@ def test_model_ids_and_filtering():
     # A filter matching nothing yields nothing, it does not fall back to all.
     table["together"].filter = ["zzz"]
     assert providers.apply_filter(table["together"], listed) == []
+    # An empty needle is a typo rather than a request to hide everything, so
+    # it means no filter. The opposite of the "zzz" case above, deliberately.
+    table["together"].filter = [""]
+    assert providers.apply_filter(table["together"], listed) == listed
     print("ok  model ids and filtering")