feat: complete remaining Go backend modules

backend/internal/httpapi/openapi_contract_test.go

@@ -0,0 +1,67 @@
+package httpapi
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+)
+
+func TestOpenAPIDocumentFreezesPublicSurface(t *testing.T) {
+	document := openAPIDocument("https://app.example.test")
+	if document["openapi"] != "3.1.0" {
+		t.Fatalf("openapi=%v", document["openapi"])
+	}
+
+	servers := document["servers"].([]any)
+	if got := servers[0].(map[string]any)["url"]; got != "https://app.example.test" {
+		t.Fatalf("server url=%v", got)
+	}
+
+	components := document["components"].(map[string]any)
+	schemas := components["schemas"].(map[string]any)
+	gotSchemas := make([]string, 0, len(schemas))
+	for name := range schemas {
+		gotSchemas = append(gotSchemas, name)
+	}
+	sort.Strings(gotSchemas)
+	wantSchemas := []string{
+		"Asset", "CreateJobRequest", "ErrorResponse", "GenerationCapability",
+		"GenerationJob", "GenerationStatus", "PromptMaterial", "RegisterAssetRequest",
+		"WebhookPayload",
+	}
+	sort.Strings(wantSchemas)
+	if !reflect.DeepEqual(gotSchemas, wantSchemas) {
+		t.Fatalf("schemas=%v", gotSchemas)
+	}
+
+	paths := document["paths"].(map[string]any)
+	gotPaths := make([]string, 0, len(paths))
+	for path := range paths {
+		gotPaths = append(gotPaths, path)
+	}
+	sort.Strings(gotPaths)
+	wantPaths := []string{
+		"/api/v1/assets", "/api/v1/assets/{id}", "/api/v1/assets/{id}/download",
+		"/api/v1/capabilities", "/api/v1/jobs", "/api/v1/jobs/{id}",
+		"/api/v1/jobs/{id}/cancel",
+	}
+	if !reflect.DeepEqual(gotPaths, wantPaths) {
+		t.Fatalf("paths=%v", gotPaths)
+	}
+
+	jobs := paths["/api/v1/jobs"].(map[string]any)
+	if jobs["get"] == nil || jobs["post"] == nil {
+		t.Fatalf("jobs verbs=%v", jobs)
+	}
+	assets := paths["/api/v1/assets"].(map[string]any)
+	requestBody := assets["post"].(map[string]any)["requestBody"].(map[string]any)
+	content := requestBody["content"].(map[string]any)
+	if content["application/json"] == nil || content["multipart/form-data"] == nil {
+		t.Fatalf("asset content=%v", content)
+	}
+	createJob := schemas["CreateJobRequest"].(map[string]any)
+	properties := createJob["properties"].(map[string]any)
+	if properties["materials"] == nil || properties["settings"] == nil || properties["webhookUrl"] == nil {
+		t.Fatalf("create job properties=%v", properties)
+	}
+}