feat: complete contract-driven business development and MySQL integration

errors/export.go

@@ -0,0 +1,23 @@
+package apierrors
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+)
+
+// ExportCatalog writes normalized, public-only error metadata. Invoke this
+// explicitly from project tooling, using the same Catalog function registered
+// at runtime. The API CLI reads the artifact; it never executes project code.
+func ExportCatalog(w io.Writer, c Catalog) error {
+	if w == nil {
+		return errors.New("errors: catalog export writer required")
+	}
+	registry, err := NewRegistry(c)
+	if err != nil {
+		return err
+	}
+	encoder := json.NewEncoder(w)
+	encoder.SetIndent("", "  ")
+	return encoder.Encode(registry.Catalog())
+}

errors/export_test.go

@@ -0,0 +1,40 @@
+package apierrors
+
+import (
+	"bytes"
+	"errors"
+	"strings"
+	"testing"
+)
+
+type failedExport struct{ err error }
+
+func (w failedExport) Write([]byte) (int, error) { return 0, w.err }
+func TestCatalogExport(t *testing.T) {
+	catalog := Catalog{DefaultStatus: 200, Definitions: map[string]Definition{"INVALID": {Code: int64(9007199254740993), Message: "invalid"}}}
+	var out bytes.Buffer
+	if err := ExportCatalog(&out, catalog); err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(out.String(), "9007199254740993") {
+		t.Fatal(out.String())
+	}
+	var decoded Catalog
+	if err := DecodeCatalogJSON(out.Bytes(), &decoded); err != nil {
+		t.Fatal(err)
+	}
+	registry, err := NewRegistry(decoded)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if registry.Resolve(ByCode("INVALID")).Status != 200 {
+		t.Fatal("status lost")
+	}
+	cause := errors.New("write failed")
+	if err = ExportCatalog(failedExport{cause}, catalog); !errors.Is(err, cause) {
+		t.Fatal("writer failure lost", err)
+	}
+	if err = ExportCatalog(nil, catalog); err == nil {
+		t.Fatal("nil writer accepted")
+	}
+}