Feature 08 task 1: Provider interface, typed errors and Fake provider (#33)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com> Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>
2026-10-03 16:14:12 -04:00
parent 7cc96121e4
commit 72042516e2
6 changed files with 665 additions and 0 deletions
@@ -0,0 +1,138 @@
+package llm
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestFakeGenerateReturnsScriptInOrder(t *testing.T) {
+	ctx := context.Background()
+	var f Fake
+	f.QueueGenerate(
+		GenerateResult{Response: Response{Text: "first", Model: "m1"}},
+		GenerateResult{Err: &RateLimitedError{RetryAfter: time.Second}},
+	)
+	f.QueueGenerate(GenerateResult{Response: Response{JSON: json.RawMessage(`{"ok":true}`), FinishReason: "stop"}})
+
+	req := Request{Messages: []Message{{Role: RoleUser, Content: "one"}}}
+	resp, err := f.Generate(ctx, req)
+	if err != nil || resp.Text != "first" || resp.Model != "m1" {
+		t.Fatalf("call 1 = %+v, %v", resp, err)
+	}
+	if _, err := f.Generate(ctx, req); !errors.Is(err, ErrRateLimited) {
+		t.Fatalf("call 2 err = %v, want ErrRateLimited", err)
+	}
+	resp, err = f.Generate(ctx, req)
+	if err != nil || string(resp.JSON) != `{"ok":true}` || resp.FinishReason != "stop" {
+		t.Fatalf("call 3 = %+v, %v", resp, err)
+	}
+	if _, err := f.Generate(ctx, req); err == nil {
+		t.Fatal("unscripted call 4 succeeded")
+	}
+	if g, l, v := f.Remaining(); g != 0 || l != 0 || v != 0 {
+		t.Fatalf("Remaining() = %d, %d, %d", g, l, v)
+	}
+	if n := len(f.Requests()); n != 4 {
+		t.Fatalf("recorded %d requests, want 4 (unscripted calls are recorded too)", n)
+	}
+}
+
+func TestFakeRecordsRequests(t *testing.T) {
+	var f Fake
+	f.QueueGenerate(GenerateResult{}, GenerateResult{})
+	temp := 0.2
+	first := Request{
+		System:      "be brief",
+		Messages:    []Message{{Role: RoleUser, Content: "plan dinners"}},
+		Temperature: &temp,
+		MaxTokens:   100,
+		Schema:      &JSONSchema{Name: "plan", Schema: json.RawMessage(`{"type":"object"}`)},
+		Timeout:     5 * time.Second,
+	}
+	if _, err := f.Generate(context.Background(), first); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := f.Generate(context.Background(), Request{System: "second"}); err != nil {
+		t.Fatal(err)
+	}
+
+	// Later changes by the caller must not alter what was recorded.
+	first.Messages[0].Content = "changed"
+	temp = 1
+	first.Schema.Schema[2] = 'X'
+
+	got := f.Requests()
+	if len(got) != 2 || got[1].System != "second" {
+		t.Fatalf("Requests() = %+v", got)
+	}
+	r := got[0]
+	if r.System != "be brief" || r.Messages[0].Content != "plan dinners" || *r.Temperature != 0.2 ||
+		r.MaxTokens != 100 || r.Schema.Name != "plan" || string(r.Schema.Schema) != `{"type":"object"}` ||
+		r.Timeout != 5*time.Second {
+		t.Fatalf("recorded request = %+v", r)
+	}
+
+	// Changing a returned copy must not alter the record either.
+	got[0].Messages[0].Content = "mutated"
+	if f.Requests()[0].Messages[0].Content != "plan dinners" {
+		t.Fatal("Requests() returned shared state")
+	}
+}
+
+func TestFakeListModelsAndVerify(t *testing.T) {
+	ctx := context.Background()
+	var f Fake
+	f.QueueListModels(
+		ListModelsResult{Models: []Model{{ID: "a", DisplayName: "A"}, {ID: "b", DisplayName: "b"}}},
+		ListModelsResult{Err: ErrAuth},
+	)
+	f.QueueVerify(nil, fmt.Errorf("wrapped: %w", ErrAuth))
+
+	models, err := f.ListModels(ctx)
+	if err != nil || len(models) != 2 || models[0].ID != "a" {
+		t.Fatalf("ListModels 1 = %+v, %v", models, err)
+	}
+	if _, err := f.ListModels(ctx); !errors.Is(err, ErrAuth) {
+		t.Fatalf("ListModels 2 err = %v, want ErrAuth", err)
+	}
+	if _, err := f.ListModels(ctx); err == nil {
+		t.Fatal("unscripted ListModels succeeded")
+	}
+	if err := f.Verify(ctx); err != nil {
+		t.Fatalf("Verify 1 = %v", err)
+	}
+	if err := f.Verify(ctx); !errors.Is(err, ErrAuth) {
+		t.Fatalf("Verify 2 = %v, want ErrAuth", err)
+	}
+	if err := f.Verify(ctx); err == nil {
+		t.Fatal("unscripted Verify succeeded")
+	}
+}
+
+func TestFakeConcurrentUse(t *testing.T) {
+	const n = 50
+	var f Fake
+	for i := range n {
+		f.QueueGenerate(GenerateResult{Response: Response{Text: fmt.Sprint(i)}})
+	}
+	var wg sync.WaitGroup
+	for range n {
+		wg.Go(func() {
+			if _, err := f.Generate(context.Background(), Request{}); err != nil {
+				t.Error(err)
+			}
+		})
+	}
+	wg.Wait()
+	if len(f.Requests()) != n {
+		t.Fatalf("recorded %d requests, want %d", len(f.Requests()), n)
+	}
+	if g, _, _ := f.Remaining(); g != 0 {
+		t.Fatalf("%d Generate results unused", g)
+	}
+}