1 files changed, 416 insertions, 0 deletions
diff --git a/internal/provider/anthropic/anthropic_test.go b/internal/provider/anthropic/anthropic_test.go
new file mode 100644
index 0000000..ca7e778
--- /dev/null
+++ b/internal/provider/anthropic/anthropic_test.go
@@ -0,0 +1,416 @@
+package anthropic
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/thepeterstone/claudomator/internal/provider"
+	"github.com/thepeterstone/claudomator/internal/retry"
+)
+
+// fakeAnthropicServer replies to POST /v1/messages with the given status and
+// raw JSON body, capturing the last decoded request for assertions. Modeled
+// on the fake OpenAI-compatible server pattern used in
+// internal/llm/client_test.go and internal/executor/nativerunner_test.go
+// (fakeChatServer), adapted to the Anthropic Messages API wire shape.
+func fakeAnthropicServer(t *testing.T, status int, body string, capture *wireRequest) *httptest.Server {
+	t.Helper()
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/v1/messages" {
+			t.Errorf("unexpected path %q", r.URL.Path)
+		}
+		if r.Header.Get("x-api-key") != "test-key" {
+			t.Errorf("missing/wrong x-api-key header: %q", r.Header.Get("x-api-key"))
+		}
+		if r.Header.Get("anthropic-version") != APIVersion {
+			t.Errorf("missing/wrong anthropic-version header: %q", r.Header.Get("anthropic-version"))
+		}
+		if r.Header.Get("content-type") != "application/json" {
+			t.Errorf("missing/wrong content-type header: %q", r.Header.Get("content-type"))
+		}
+		if capture != nil {
+			if err := json.NewDecoder(r.Body).Decode(capture); err != nil {
+				t.Fatalf("decode request body: %v", err)
+			}
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(status)
+		w.Write([]byte(body))
+	}))
+}
+
+func newTestProvider(url string) *Provider {
+	return New("test-key", url, 5*time.Second)
+}
+
+// TestChat_PlainTextResponse covers a plain assistant text reply: no tool
+// calls, stop_reason "end_turn", usage translated to provider.Usage with a
+// non-zero CostUSD computed from the pricing table.
+func TestChat_PlainTextResponse(t *testing.T) {
+	var got wireRequest
+	srv := fakeAnthropicServer(t, http.StatusOK, `{
+		"id": "msg_1",
+		"type": "message",
+		"role": "assistant",
+		"model": "claude-sonnet-5",
+		"content": [{"type": "text", "text": "Hello there!"}],
+		"stop_reason": "end_turn",
+		"usage": {"input_tokens": 10, "output_tokens": 5}
+	}`, &got)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	resp, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model:  "claude-sonnet-5",
+		System: "You are helpful.",
+		Messages: []provider.Message{
+			{Role: "user", Text: "hi"},
+		},
+	})
+	if err != nil {
+		t.Fatalf("Chat: %v", err)
+	}
+	if resp.Text != "Hello there!" {
+		t.Errorf("Text: want %q got %q", "Hello there!", resp.Text)
+	}
+	if len(resp.ToolCalls) != 0 {
+		t.Errorf("expected no tool calls, got %+v", resp.ToolCalls)
+	}
+	if resp.StopReason != "end_turn" {
+		t.Errorf("StopReason: want end_turn got %q", resp.StopReason)
+	}
+	if resp.Usage.InputTokens != 10 || resp.Usage.OutputTokens != 5 {
+		t.Errorf("usage tokens: got %+v", resp.Usage)
+	}
+	wantCost := float64(10)/1_000_000*3.00 + float64(5)/1_000_000*15.00
+	if resp.Usage.CostUSD != wantCost {
+		t.Errorf("CostUSD: want %v got %v", wantCost, resp.Usage.CostUSD)
+	}
+
+	// Verify the outgoing request shape: system is top-level, not a message.
+	if got.System != "You are helpful." {
+		t.Errorf("system: want %q got %q", "You are helpful.", got.System)
+	}
+	if len(got.Messages) != 1 || got.Messages[0].Role != "user" {
+		t.Fatalf("messages: %+v", got.Messages)
+	}
+	if len(got.Messages[0].Content) != 1 || got.Messages[0].Content[0].Type != "text" || got.Messages[0].Content[0].Text != "hi" {
+		t.Errorf("user content block: %+v", got.Messages[0].Content)
+	}
+	if got.MaxTokens != defaultMaxTokens {
+		t.Errorf("max_tokens should default to %d, got %d", defaultMaxTokens, got.MaxTokens)
+	}
+}
+
+// TestChat_ToolUseResponse verifies that a response whose content mixes a
+// text block and a tool_use block round-trips into ChatResponse.ToolCalls
+// correctly (id/name/args), and that tools declared on the request are
+// translated to Anthropic's {name, description, input_schema} shape.
+func TestChat_ToolUseResponse(t *testing.T) {
+	var got wireRequest
+	srv := fakeAnthropicServer(t, http.StatusOK, `{
+		"id": "msg_2",
+		"type": "message",
+		"role": "assistant",
+		"model": "claude-opus-4-8",
+		"content": [
+			{"type": "text", "text": "Let me check that."},
+			{"type": "tool_use", "id": "toolu_01", "name": "read_file", "input": {"path": "a.txt"}}
+		],
+		"stop_reason": "tool_use",
+		"usage": {"input_tokens": 20, "output_tokens": 8}
+	}`, &got)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	resp, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model:    "claude-opus-4-8",
+		Messages: []provider.Message{{Role: "user", Text: "read a.txt"}},
+		Tools: []provider.ToolSpec{
+			{
+				Name:        "read_file",
+				Description: "Read a file.",
+				ParametersJSONSchema: map[string]any{
+					"type":       "object",
+					"properties": map[string]any{"path": map[string]any{"type": "string"}},
+					"required":   []string{"path"},
+				},
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("Chat: %v", err)
+	}
+	if resp.Text != "Let me check that." {
+		t.Errorf("Text: got %q", resp.Text)
+	}
+	if resp.StopReason != "tool_use" {
+		t.Errorf("StopReason: want tool_use got %q", resp.StopReason)
+	}
+	if len(resp.ToolCalls) != 1 {
+		t.Fatalf("expected 1 tool call, got %d: %+v", len(resp.ToolCalls), resp.ToolCalls)
+	}
+	tc := resp.ToolCalls[0]
+	if tc.ID != "toolu_01" || tc.Name != "read_file" {
+		t.Errorf("tool call id/name: got %+v", tc)
+	}
+	var args struct {
+		Path string `json:"path"`
+	}
+	if err := json.Unmarshal([]byte(tc.ArgsJSON), &args); err != nil {
+		t.Fatalf("tool call args not valid JSON: %v (%q)", err, tc.ArgsJSON)
+	}
+	if args.Path != "a.txt" {
+		t.Errorf("tool call args.path: got %q", args.Path)
+	}
+
+	// Verify tools were declared with input_schema (not "parameters").
+	if len(got.Tools) != 1 {
+		t.Fatalf("expected 1 tool declared, got %d", len(got.Tools))
+	}
+	if got.Tools[0].Name != "read_file" || got.Tools[0].Description != "Read a file." {
+		t.Errorf("tool declaration: %+v", got.Tools[0])
+	}
+	if got.Tools[0].InputSchema == nil || got.Tools[0].InputSchema["type"] != "object" {
+		t.Errorf("tool input_schema not forwarded: %+v", got.Tools[0].InputSchema)
+	}
+}
+
+// TestChat_MultiTurnWithPriorToolResult exercises the tool_result-as-a-
+// user-message translation: a provider.Message carrying ToolResults (as
+// agentloop.Loop emits with Role "tool" after dispatching a tool call) must
+// serialize as a user-role message with tool_result content blocks —
+// Anthropic has no "tool" role. Also verifies a prior assistant turn with a
+// tool call round-trips into a single assistant message with a tool_use
+// block matching the id used in the subsequent tool_result.
+func TestChat_MultiTurnWithPriorToolResult(t *testing.T) {
+	var got wireRequest
+	srv := fakeAnthropicServer(t, http.StatusOK, `{
+		"id": "msg_3",
+		"type": "message",
+		"role": "assistant",
+		"model": "claude-sonnet-5",
+		"content": [{"type": "text", "text": "The file says hello."}],
+		"stop_reason": "end_turn",
+		"usage": {"input_tokens": 30, "output_tokens": 6}
+	}`, &got)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model: "claude-sonnet-5",
+		Messages: []provider.Message{
+			{Role: "user", Text: "read a.txt"},
+			{
+				Role: "assistant",
+				Text: "",
+				ToolCalls: []provider.ToolCall{
+					{ID: "toolu_01", Name: "read_file", ArgsJSON: `{"path":"a.txt"}`},
+				},
+			},
+			{
+				Role: "tool",
+				ToolResults: []provider.ToolResult{
+					{ToolCallID: "toolu_01", Name: "read_file", Content: "hello", IsError: false},
+				},
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("Chat: %v", err)
+	}
+
+	if len(got.Messages) != 3 {
+		t.Fatalf("expected 3 wire messages, got %d: %+v", len(got.Messages), got.Messages)
+	}
+
+	// Turn 2: assistant tool_use, no text block since Text was empty.
+	asst := got.Messages[1]
+	if asst.Role != "assistant" {
+		t.Errorf("turn 2 role: want assistant got %q", asst.Role)
+	}
+	if len(asst.Content) != 1 || asst.Content[0].Type != "tool_use" {
+		t.Fatalf("turn 2 content: %+v", asst.Content)
+	}
+	if asst.Content[0].ID != "toolu_01" || asst.Content[0].Name != "read_file" {
+		t.Errorf("turn 2 tool_use block: %+v", asst.Content[0])
+	}
+
+	// Turn 3: the tool result must be a USER-role message with a
+	// tool_result block (Anthropic has no "tool" role).
+	toolTurn := got.Messages[2]
+	if toolTurn.Role != "user" {
+		t.Errorf("tool result turn role: want user (Anthropic has no tool role) got %q", toolTurn.Role)
+	}
+	if len(toolTurn.Content) != 1 || toolTurn.Content[0].Type != "tool_result" {
+		t.Fatalf("tool result content: %+v", toolTurn.Content)
+	}
+	block := toolTurn.Content[0]
+	if block.ToolUseID != "toolu_01" {
+		t.Errorf("tool_use_id: want toolu_01 got %q", block.ToolUseID)
+	}
+	if block.Content != "hello" {
+		t.Errorf("tool_result content: want hello got %q", block.Content)
+	}
+	if block.IsError {
+		t.Errorf("is_error should be false")
+	}
+}
+
+// TestChat_ToolResultIsError verifies IsError round-trips onto the
+// tool_result block's is_error field.
+func TestChat_ToolResultIsError(t *testing.T) {
+	var got wireRequest
+	srv := fakeAnthropicServer(t, http.StatusOK, `{
+		"content": [{"type": "text", "text": "ok"}],
+		"stop_reason": "end_turn",
+		"usage": {"input_tokens": 1, "output_tokens": 1}
+	}`, &got)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model: "claude-sonnet-5",
+		Messages: []provider.Message{
+			{Role: "tool", ToolResults: []provider.ToolResult{
+				{ToolCallID: "toolu_x", Name: "run_bash", Content: "boom", IsError: true},
+			}},
+		},
+	})
+	if err != nil {
+		t.Fatalf("Chat: %v", err)
+	}
+	if len(got.Messages) != 1 || len(got.Messages[0].Content) != 1 {
+		t.Fatalf("unexpected messages: %+v", got.Messages)
+	}
+	if !got.Messages[0].Content[0].IsError {
+		t.Errorf("expected is_error true")
+	}
+}
+
+// TestChat_RateLimitError429 verifies a 429 rate_limit_error response
+// produces a Go error whose text retry.IsRateLimitError recognizes.
+func TestChat_RateLimitError429(t *testing.T) {
+	srv := fakeAnthropicServer(t, http.StatusTooManyRequests, `{
+		"type": "error",
+		"error": {"type": "rate_limit_error", "message": "Number of requests has exceeded your rate limit."}
+	}`, nil)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model:    "claude-sonnet-5",
+		Messages: []provider.Message{{Role: "user", Text: "hi"}},
+	})
+	if err == nil {
+		t.Fatal("expected an error for HTTP 429")
+	}
+	if !strings.Contains(err.Error(), "429") || !strings.Contains(err.Error(), "rate_limit_error") {
+		t.Errorf("error should mention 429 and rate_limit_error, got: %v", err)
+	}
+	if !retry.IsRateLimitError(err) {
+		t.Errorf("retry.IsRateLimitError should recognize: %v", err)
+	}
+}
+
+// TestChat_OverloadedError529 verifies a 529 overloaded_error response is
+// also recognized as retryable.
+func TestChat_OverloadedError529(t *testing.T) {
+	srv := fakeAnthropicServer(t, 529, `{
+		"type": "error",
+		"error": {"type": "overloaded_error", "message": "Overloaded"}
+	}`, nil)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model:    "claude-sonnet-5",
+		Messages: []provider.Message{{Role: "user", Text: "hi"}},
+	})
+	if err == nil {
+		t.Fatal("expected an error for HTTP 529")
+	}
+	if !retry.IsRateLimitError(err) {
+		t.Errorf("retry.IsRateLimitError should recognize overloaded_error: %v", err)
+	}
+}
+
+// TestChat_InvalidRequestError400 is a non-retryable error case: confirms
+// the error text carries the invalid_request_error type and is NOT
+// misclassified as a rate-limit error.
+func TestChat_InvalidRequestError400(t *testing.T) {
+	srv := fakeAnthropicServer(t, http.StatusBadRequest, `{
+		"type": "error",
+		"error": {"type": "invalid_request_error", "message": "max_tokens: field required"}
+	}`, nil)
+	defer srv.Close()
+
+	p := newTestProvider(srv.URL)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{
+		Model:    "claude-sonnet-5",
+		Messages: []provider.Message{{Role: "user", Text: "hi"}},
+	})
+	if err == nil {
+		t.Fatal("expected an error for HTTP 400")
+	}
+	if !strings.Contains(err.Error(), "invalid_request_error") {
+		t.Errorf("error should mention invalid_request_error, got: %v", err)
+	}
+	if retry.IsRateLimitError(err) {
+		t.Errorf("400 invalid_request_error should NOT be classified as a rate-limit error: %v", err)
+	}
+}
+
+// TestChat_NoAPIKey_Errors confirms Chat fails fast without ever making an
+// HTTP request when no API key is configured.
+func TestChat_NoAPIKey_Errors(t *testing.T) {
+	p := New("", "http://127.0.0.1:1", time.Second)
+	_, err := p.Chat(context.Background(), provider.ChatRequest{Model: "claude-sonnet-5"})
+	if err == nil || !strings.Contains(err.Error(), "no API key") {
+		t.Errorf("expected 'no API key' error, got %v", err)
+	}
+}
+
+// TestNew_DefaultsEndpointAndTimeout verifies New falls back to
+// DefaultEndpoint/DefaultTimeout for zero-value arguments.
+func TestNew_DefaultsEndpointAndTimeout(t *testing.T) {
+	p := New("key", "", 0)
+	if p.Endpoint != DefaultEndpoint {
+		t.Errorf("Endpoint: want %q got %q", DefaultEndpoint, p.Endpoint)
+	}
+	if p.HTTPClient.Timeout != DefaultTimeout {
+		t.Errorf("Timeout: want %v got %v", DefaultTimeout, p.HTTPClient.Timeout)
+	}
+}
+
+// TestName returns the provider's identifier, used as the agent-type/budget
+// key ("anthropic") once wired into a NativeRunner.
+func TestName(t *testing.T) {
+	p := New("key", "", 0)
+	if p.Name() != "anthropic" {
+		t.Errorf("Name: got %q", p.Name())
+	}
+}
+
+// TestPricingFor_KnownAndUnknownModels sanity-checks the pricing table
+// lookup: exact/prefix match for known models, and a non-erroring fallback
+// for an unrecognized model string.
+func TestPricingFor_KnownAndUnknownModels(t *testing.T) {
+	in, out := pricingFor("claude-opus-4-8")
+	if in != 5.00 || out != 25.00 {
+		t.Errorf("opus 4.8 pricing: got %v/%v", in, out)
+	}
+	in, out = pricingFor("claude-haiku-4-5-20251001")
+	if in != 1.00 || out != 5.00 {
+		t.Errorf("haiku 4.5 dated snapshot pricing: got %v/%v", in, out)
+	}
+	in, out = pricingFor("some-future-unknown-model")
+	if in != defaultPricing.InputPerMTok || out != defaultPricing.OutputPerMTok {
+		t.Errorf("unknown model should fall back to default pricing, got %v/%v", in, out)
+	}
+}