feat(exec): add LiteLLM HTTP executor for local model dispatch

internal/exec/litellm_test.go

@@ -0,0 +1,112 @@
+package exec_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	iexec "github.com/mathiasbq/supervisor/internal/exec"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func validLiteLLMResult() iexec.Result {
+	return iexec.Result{
+		Status:    "pass",
+		Phase:     "review",
+		Skill:     "review",
+		ModelUsed: "ollama/devstral",
+		Message:   "looks good",
+	}
+}
+
+func chatResponseFor(t *testing.T, result iexec.Result) []byte {
+	t.Helper()
+	content, err := json.Marshal(result)
+	require.NoError(t, err)
+	resp := map[string]any{
+		"choices": []map[string]any{
+			{"message": map[string]any{"role": "assistant", "content": string(content)}},
+		},
+	}
+	data, err := json.Marshal(resp)
+	require.NoError(t, err)
+	return data
+}
+
+func TestLiteLLMParsesValidResult(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "/v1/chat/completions", r.URL.Path)
+		assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(chatResponseFor(t, validLiteLLMResult()))
+	}))
+	defer srv.Close()
+
+	ex := iexec.NewLiteLLM(srv.URL, "", 5*time.Second)
+	result, err := ex.Run(context.Background(), iexec.Request{
+		SkillPrompt: "review rules",
+		TaskPrompt:  "review the code",
+		Model:       "ollama/devstral",
+	})
+	require.NoError(t, err)
+	assert.Equal(t, "pass", result.Status)
+	assert.Equal(t, "review", result.Skill)
+}
+
+func TestLiteLLMSendsAuthHeader(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "Bearer secret", r.Header.Get("Authorization"))
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(chatResponseFor(t, validLiteLLMResult()))
+	}))
+	defer srv.Close()
+
+	ex := iexec.NewLiteLLM(srv.URL, "secret", 5*time.Second)
+	_, err := ex.Run(context.Background(), iexec.Request{Model: "x", TaskPrompt: "t", SkillPrompt: "s"})
+	require.NoError(t, err)
+}
+
+func TestLiteLLMErrorOnNonOKStatus(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}))
+	defer srv.Close()
+
+	ex := iexec.NewLiteLLM(srv.URL, "", 5*time.Second)
+	_, err := ex.Run(context.Background(), iexec.Request{Model: "x", TaskPrompt: "t"})
+	assert.ErrorContains(t, err, "503")
+}
+
+func TestLiteLLMErrorOnUnparsableJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{"message": map[string]any{"role": "assistant", "content": "not json at all"}},
+			},
+		}
+		data, _ := json.Marshal(resp)
+		_, _ = w.Write(data)
+	}))
+	defer srv.Close()
+
+	ex := iexec.NewLiteLLM(srv.URL, "", 5*time.Second)
+	_, err := ex.Run(context.Background(), iexec.Request{Model: "x", TaskPrompt: "t"})
+	assert.Error(t, err)
+}
+
+func TestLiteLLMRespectsContextCancellation(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // Cancel immediately
+
+	ex := iexec.NewLiteLLM("http://invalid.example.com", "", 1*time.Second)
+	_, err := ex.Run(ctx, iexec.Request{Model: "x", TaskPrompt: "t"})
+	assert.Error(t, err)
+}