test: add behavioural regression tests for #1188 fuzzy-match fix

nesquena · claude · nesquena · commit 612655201d45 · 2026-04-27T17:52:36.000-07:00
9 tests run the live _findModelInDropdown function via Node so the real
regex/normalization rules are exercised (no Python mirror to drift).

Two locked-bad cases (gpt-5.5 → gpt-5.4-mini, claude-opus-4.7 →
claude-opus-4.6) reproduce on master and pass on the PR. Seven
preserved-good cases (bare-root prefix match, exact match, unrelated)
ensure the tighter check doesn't regress legit fuzzy lookups.

Co-Authored-By: Claude Opus 4.7 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/tests/test_issue1188_fuzzy_match.py b/tests/test_issue1188_fuzzy_match.py
@@ -0,0 +1,153 @@
+"""
+Regression tests for #1188 — _findModelInDropdown step-3 fuzzy match
+returning a sibling-version model when the user's session model is unique.
+
+The pre-fix logic stripped the trailing version segment from the target
+(e.g. ``gpt-5.5`` → base ``gpt.5``) and matched against any option that
+``startsWith(base)`` or ``includes(base)``. That over-matched: ``gpt.5.5``
+returned ``@nous:openai/gpt-5.4-mini`` because ``gpt.5.4.mini`` starts
+with ``gpt.5``.
+
+The fix: use the FULL normalized target as the prefix when the stripped
+base has meaningful content (length > 4 and base !== target). Only fall
+back to the shorter base when it is a bare root word (``gpt``, ``claude``,
+length ≤ 4) where stripping was effectively a no-op.
+
+Tests below run the live ``_findModelInDropdown`` function via Node so
+the real regex/normalization rules are exercised — drift between this
+test and the JS would be caught by behavioural mismatch.
+"""
+import shutil
+import subprocess
+
+import pytest
+
+REPO_ROOT = __import__("pathlib").Path(__file__).parent.parent.resolve()
+UI_JS_PATH = REPO_ROOT / "static" / "ui.js"
+NODE = shutil.which("node")
+
+pytestmark = pytest.mark.skipif(NODE is None, reason="node not on PATH")
+
+
+_DRIVER_SRC = r"""
+const fs = require('fs');
+const ui = fs.readFileSync(process.argv[2], 'utf8');
+function extractFunc(name) {
+  const re = new RegExp('function\\s+' + name + '\\s*\\(');
+  const start = ui.search(re);
+  if (start < 0) throw new Error(name + ' not found');
+  let i = ui.indexOf('{', start);
+  let depth = 1; i++;
+  while (depth > 0 && i < ui.length) {
+    if (ui[i] === '{') depth++;
+    else if (ui[i] === '}') depth--;
+    i++;
+  }
+  return ui.slice(start, i);
+}
+eval(extractFunc('_findModelInDropdown'));
+const args = JSON.parse(process.argv[3]);
+const sel = { options: args.options.map(v => ({value: v})) };
+const got = _findModelInDropdown(args.modelId, sel);
+process.stdout.write(JSON.stringify(got));
+"""
+
+
+@pytest.fixture(scope="module")
+def driver_path(tmp_path_factory):
+    p = tmp_path_factory.mktemp("findmodel_driver") / "driver.js"
+    p.write_text(_DRIVER_SRC, encoding="utf-8")
+    return str(p)
+
+
+def _find(driver_path, model_id: str, options: list[str]):
+    import json
+    result = subprocess.run(
+        [NODE, driver_path, str(UI_JS_PATH),
+         json.dumps({"modelId": model_id, "options": options})],
+        capture_output=True, text=True, timeout=10,
+    )
+    if result.returncode != 0:
+        raise RuntimeError(f"node driver failed: {result.stderr}")
+    return json.loads(result.stdout)
+
+
+# ── Regression: original #1188 false-match cases ───────────────────────────
+
+
+class TestNoFalseSiblingVersionMatch:
+    def test_gpt_5_5_does_not_match_gpt_5_4_mini(self, driver_path):
+        """The exact bug from #1188: session model gpt-5.5 should NOT
+        resolve to @nous:openai/gpt-5.4-mini just because both share
+        the gpt.5 prefix once the trailing version is stripped."""
+        got = _find(
+            driver_path,
+            "gpt-5.5",
+            ["@nous:openai/gpt-5.4-mini", "@nous:anthropic/claude-opus-4.6"],
+        )
+        assert got is None, (
+            "gpt-5.5 must not fuzzy-match gpt-5.4-mini (#1188)"
+        )
+
+    def test_claude_opus_4_7_does_not_match_claude_opus_4_6(self, driver_path):
+        """Same shape: a different minor version must not be a fuzzy hit."""
+        got = _find(
+            driver_path,
+            "claude-opus-4.7",
+            ["@nous:anthropic/claude-opus-4.6"],
+        )
+        assert got is None, (
+            "claude-opus-4.7 must not fuzzy-match claude-opus-4.6"
+        )
+
+
+# ── Things that should still match (no regression for legit fuzzy use) ─────
+
+
+class TestPreservedFuzzyMatches:
+    def test_gpt_5_5_finds_exact_provider_prefixed(self, driver_path):
+        got = _find(
+            driver_path,
+            "gpt-5.5",
+            ["@nous:openai/gpt-5.5", "@nous:openai/gpt-5.4-mini"],
+        )
+        assert got == "@nous:openai/gpt-5.5"
+
+    def test_bare_root_gpt_matches_versioned_option(self, driver_path):
+        """Short root targets still fall back to the looser prefix match."""
+        got = _find(driver_path, "gpt", ["@nous:openai/gpt-5.4-mini"])
+        assert got == "@nous:openai/gpt-5.4-mini"
+
+    def test_short_target_gpt_5_falls_back_to_bare_root(self, driver_path):
+        """When base after stripping is a bare root (length ≤ 4),
+        fall back so user-typed shorthand still resolves."""
+        got = _find(driver_path, "gpt-5", ["@nous:openai/gpt-5.4-mini"])
+        assert got == "@nous:openai/gpt-5.4-mini"
+
+    def test_bare_root_claude_matches(self, driver_path):
+        got = _find(
+            driver_path, "claude", ["@nous:anthropic/claude-opus-4.6"]
+        )
+        assert got == "@nous:anthropic/claude-opus-4.6"
+
+    def test_target_without_version_suffix_still_matches(self, driver_path):
+        """claude-opus has no trailing version → base === target → useBase
+        path → still finds claude-opus-4.6 via prefix."""
+        got = _find(
+            driver_path, "claude-opus", ["@nous:anthropic/claude-opus-4.6"]
+        )
+        assert got == "@nous:anthropic/claude-opus-4.6"
+
+    def test_exact_match_short_circuits(self, driver_path):
+        got = _find(
+            driver_path,
+            "gpt-5.4-mini",
+            ["@nous:openai/gpt-5.4-mini", "@nous:openai/gpt-5.5"],
+        )
+        assert got == "@nous:openai/gpt-5.4-mini"
+
+    def test_unrelated_target_returns_null(self, driver_path):
+        got = _find(
+            driver_path, "mistral-large", ["@nous:openai/gpt-5.4-mini"]
+        )
+        assert got is None
