2 files changed, 30 insertions, 0 deletions
diff --git a/internal/llm/provider_test.go b/internal/llm/provider_test.go
new file mode 100644
index 0000000..1412b3c
--- /dev/null
+++ b/internal/llm/provider_test.go
@@ -0,0 +1,21 @@
+package llm
+
+import (
+    "context"
+    "testing"
+)
+
+func TestNewFromConfig_DefaultsAndErrors(t *testing.T) {
+    // Unknown provider
+    if _, err := NewFromConfig(Config{Provider:"bogus"}, "", ""); err == nil { t.Fatalf("expected error for unknown provider") }
+    // OpenAI missing key
+    if _, err := NewFromConfig(Config{Provider:"openai", OpenAIModel:"g"}, "", ""); err == nil { t.Fatalf("expected key error") }
+    // Copilot missing key
+    if _, err := NewFromConfig(Config{Provider:"copilot", CopilotModel:"m"}, "", ""); err == nil { t.Fatalf("expected key error") }
+}
+
+type fakeClientMin struct{}
+func (fakeClientMin) Chat(context.Context, []Message, ...RequestOption) (string, error) { return "", nil }
+func (fakeClientMin) Name() string { return "x" }
+func (fakeClientMin) DefaultModel() string { return "m" }
+
diff --git a/internal/llm/util_test.go b/internal/llm/util_test.go
new file mode 100644
index 0000000..acffe5a
--- /dev/null
+++ b/internal/llm/util_test.go
@@ -0,0 +1,9 @@
+package llm
+
+import "testing"
+
+func TestNilStringErr(t *testing.T) {
+    s, err := nilStringErr("boom")
+    if s != "" || err == nil { t.Fatalf("expected empty string and error") }
+}
+