Add conflict resolution diff UI and app branding

apps/server/internal/docs/service_test.go

@@ -1,8 +1,18 @@
 package docs
 
 import (
+	"context"
+	"database/sql"
+	"errors"
+	"log/slog"
+	"os"
+	"path/filepath"
 	"reflect"
 	"testing"
+
+	"github.com/tim/cairnquire/apps/server/internal/database"
+	"github.com/tim/cairnquire/apps/server/internal/markdown"
+	"github.com/tim/cairnquire/apps/server/internal/store"
 )
 
 func TestNormalizeRequestPathCandidatesSupportsIndexFiles(t *testing.T) {
@@ -37,3 +47,95 @@ func TestNormalizeRequestPathCandidatesSupportsIndexFiles(t *testing.T) {
 		})
 	}
 }
+
+func TestSaveSourcePageWithBaseHashRejectsStaleEditor(t *testing.T) {
+	service, sourceDir := setupDocsTestService(t)
+	ctx := context.Background()
+
+	page, err := service.LoadSourcePage(ctx, "hello")
+	if err != nil {
+		t.Fatalf("LoadSourcePage() error = %v", err)
+	}
+
+	serverContent := "# Hello\n\nServer edit"
+	if err := os.WriteFile(filepath.Join(sourceDir, "hello.md"), []byte(serverContent), 0o644); err != nil {
+		t.Fatalf("write server edit: %v", err)
+	}
+
+	_, err = service.SaveSourcePageWithBaseHash(ctx, "hello", "# Hello\n\nClient edit", page.Hash)
+	var conflict *DocumentConflictError
+	if !errors.As(err, &conflict) {
+		t.Fatalf("SaveSourcePageWithBaseHash() error = %v, want DocumentConflictError", err)
+	}
+	if conflict.BaseHash != page.Hash {
+		t.Fatalf("conflict base hash = %q, want %q", conflict.BaseHash, page.Hash)
+	}
+	if conflict.CurrentContent != serverContent {
+		t.Fatalf("conflict current content = %q, want %q", conflict.CurrentContent, serverContent)
+	}
+
+	content, err := os.ReadFile(filepath.Join(sourceDir, "hello.md"))
+	if err != nil {
+		t.Fatalf("read hello.md: %v", err)
+	}
+	if string(content) != serverContent {
+		t.Fatalf("stale save overwrote content: %q", string(content))
+	}
+}
+
+func TestSaveSourcePageWithBaseHashAcceptsMatchingHash(t *testing.T) {
+	service, sourceDir := setupDocsTestService(t)
+	ctx := context.Background()
+
+	page, err := service.LoadSourcePage(ctx, "hello")
+	if err != nil {
+		t.Fatalf("LoadSourcePage() error = %v", err)
+	}
+
+	nextContent := "# Hello\n\nClient edit"
+	updated, err := service.SaveSourcePageWithBaseHash(ctx, "hello", nextContent, page.Hash)
+	if err != nil {
+		t.Fatalf("SaveSourcePageWithBaseHash() error = %v", err)
+	}
+	if updated.Hash == page.Hash {
+		t.Fatal("expected hash to change after save")
+	}
+
+	content, err := os.ReadFile(filepath.Join(sourceDir, "hello.md"))
+	if err != nil {
+		t.Fatalf("read hello.md: %v", err)
+	}
+	if string(content) != nextContent {
+		t.Fatalf("saved content = %q, want %q", string(content), nextContent)
+	}
+}
+
+func setupDocsTestService(t *testing.T) (*Service, string) {
+	t.Helper()
+
+	sourceDir := t.TempDir()
+	storeDir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(sourceDir, "hello.md"), []byte("# Hello\n\nOriginal"), 0o644); err != nil {
+		t.Fatalf("create hello.md: %v", err)
+	}
+
+	dbPath := filepath.Join(t.TempDir(), "test.db")
+	db, err := sql.Open("libsql", "file:"+dbPath)
+	if err != nil {
+		t.Fatalf("open database: %v", err)
+	}
+	t.Cleanup(func() { db.Close() })
+
+	ctx := context.Background()
+	if err := database.ApplyMigrations(ctx, db); err != nil {
+		t.Fatalf("apply migrations: %v", err)
+	}
+
+	contentStore, err := store.New(storeDir)
+	if err != nil {
+		t.Fatalf("create content store: %v", err)
+	}
+
+	repo := NewRepository(db)
+	return NewService(sourceDir, contentStore, markdown.NewRenderer(), repo, slog.Default()), sourceDir
+}