test: TestJournalMCP compiles the MCP declaration through pier and pins its input keys (phase 19.7 plan 05)

- the seven tools compile in pier's catalog against the plugin's routes
- every input field is a path segment, a list query key or a create/update
  body key the routes read
- the draft prompt renders with and without its optional tone

mcp_test.go

@@ -0,0 +1,149 @@
+package journal_test
+
+import (
+	"context"
+	"net/http"
+	"os"
+	"path/filepath"
+	"reflect"
+	"slices"
+	"strings"
+	"testing"
+
+	journal "git.golem15.com/golem15/sm-journal-plugin"
+	"git.golem15.com/golem15/summercms/modules/backpack"
+	"git.golem15.com/golem15/summercms/modules/compass"
+	"git.golem15.com/golem15/summercms/modules/party"
+	"git.golem15.com/golem15/summercms/modules/pier"
+	"git.golem15.com/golem15/summercms/modules/surf"
+)
+
+// The JSON keys the post routes read (controllers/api/posts_helpers.go:
+// body["..."] in the create and update validation, and the list query).
+// A tool input field outside these would be sent and silently ignored.
+var (
+	postBodyKeys  = []string{"categories", "content", "excerpt", "is_pinned", "metadata", "published", "published_at", "slug", "sources", "tags", "title", "translations"}
+	postQueryKeys = []string{"author", "category", "include_empty", "page", "per_page", "pinned_first", "published", "search", "sort", "tag"}
+)
+
+// mountHost adapts a built surf router to pier.Host for a compile-only mount.
+type mountHost struct{ r *surf.Router }
+
+func (h mountHost) Routes() []pier.RouteInfo {
+	var out []pier.RouteInfo
+	for _, ri := range h.r.Routes() {
+		out = append(out, pier.RouteInfo{Method: ri.Method, Pattern: ri.Pattern, PluginID: ri.PluginID, Middleware: ri.Middleware})
+	}
+	return out
+}
+func (h mountHost) Handler(method, pattern string) (http.Handler, bool) {
+	return h.r.Handler(method, pattern)
+}
+func (mountHost) MountStream(string, string, http.Handler, ...string) error { return nil }
+func (mountHost) MountJSON(string, string, http.Handler) error              { return nil }
+func (h mountHost) Owner(method, path string) (string, bool) {
+	for _, ri := range h.r.Routes() {
+		if ri.Method == method && ri.Pattern == path {
+			return ri.PluginID, true
+		}
+	}
+	return "", false
+}
+
+// journalApp boots the translate and journal plugins on a config without a
+// database.
+func journalApp(t *testing.T) (*backpack.App, []party.Plugin) {
+	t.Helper()
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "app.yaml"), []byte("name: journal-mcp\nlocale: en\nfallback_locale: en\nurl: https://app.example.test\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := compass.Open(compass.Options{Dir: dir, Environ: []string{"SUMMER_ENV=development", "SUMMER_ADMIN__JWT__SECRET=" + adminJWTSecret}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for key, value := range map[string]any{"http.body_limits.default_bytes": 1048576, "http.body_limits.upload_bytes": 8388608} {
+		if err := cfg.Set(key, value); err != nil {
+			t.Fatal(err)
+		}
+	}
+	app := backpack.New(cfg)
+	plugins, err := party.Activate(app, []string{"golem15.translate", "golem15.journal"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return app, plugins
+}
+
+// TestJournalMCP (D-15, D-16, SC-2) extends TestJournalMCPSmoke: the
+// declaration compiles through pier's own catalog against the routes the
+// plugin registers (prefix journal_, the backend guard, path and query
+// tags matching the patterns); every input field is a key the route reads
+// (path segment, list query key or create/update body key); the draft
+// prompt renders with and without its optional tone. The dispatch marker
+// on the optional-principal list and show routes is pinned by
+// controllers/api TestOptionalBackendPrincipalDispatch. Runs under -short.
+func TestJournalMCP(t *testing.T) {
+	decl := (&journal.Plugin{}).MCP()
+
+	t.Run("compiles through pier against the plugin's routes", func(t *testing.T) {
+		app, plugins := journalApp(t)
+		router, err := surf.BuildRouter(app, plugins)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := app.Config.Set(pier.EnabledKey, true); err != nil {
+			t.Fatal(err)
+		}
+		if err := pier.Mount(mountHost{r: router}, app, plugins); err != nil {
+			t.Fatalf("pier.Mount: %v", err)
+		}
+		p, ok := app.Lookup[*pier.Pier]()
+		if !ok {
+			t.Fatal("pier was not mounted")
+		}
+		want := []string{"journal_create_post", "journal_delete_post", "journal_list_categories", "journal_list_posts", "journal_list_tags", "journal_show_post", "journal_update_post"}
+		if got := p.ToolNames(); !slices.Equal(got, want) {
+			t.Fatalf("compiled tools %v, want %v", got, want)
+		}
+	})
+
+	t.Run("input fields are keys the routes read", func(t *testing.T) {
+		for _, tool := range decl.Tools {
+			rt := reflect.TypeOf(tool.Input)
+			for rt.Kind() == reflect.Pointer {
+				rt = rt.Elem()
+			}
+			for i := 0; i < rt.NumField(); i++ {
+				f := rt.Field(i)
+				key, _, _ := strings.Cut(f.Tag.Get("json"), ",")
+				switch {
+				case f.Tag.Get("path") != "":
+					if !strings.Contains(tool.Path, "{"+f.Tag.Get("path")+"}") {
+						t.Errorf("%s.%s: path tag %q not in %s", tool.Name, f.Name, f.Tag.Get("path"), tool.Path)
+					}
+				case f.Tag.Get("query") != "":
+					if tool.Method != http.MethodGet || !slices.Contains(postQueryKeys, f.Tag.Get("query")) {
+						t.Errorf("%s.%s: query key %q is not one the list reads", tool.Name, f.Name, f.Tag.Get("query"))
+					}
+				default:
+					if tool.Method == http.MethodGet || tool.Method == http.MethodDelete || !slices.Contains(postBodyKeys, key) {
+						t.Errorf("%s.%s: body key %q is not one %s %s reads", tool.Name, f.Name, key, tool.Method, tool.Path)
+					}
+				}
+			}
+		}
+	})
+
+	t.Run("draft prompt with and without tone", func(t *testing.T) {
+		prompt := decl.Prompts[0]
+		with, err := prompt.Render(context.Background(), map[string]string{"topic": "Spring release", "tone": "playful"})
+		if err != nil || len(with) != 1 || !strings.Contains(with[0].Text, "Spring release") || !strings.Contains(with[0].Text, "playful") {
+			t.Fatalf("with tone = %+v, %v", with, err)
+		}
+		without, err := prompt.Render(context.Background(), map[string]string{"topic": "Spring release"})
+		if err != nil || len(without) != 1 || !strings.Contains(without[0].Text, "Spring release") || strings.Contains(without[0].Text, "playful") {
+			t.Fatalf("without tone = %+v, %v", without, err)
+		}
+	})
+}