Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/config/env_reachability_test.go

@@ -0,0 +1,104 @@
+//go:build unit
+
+package config
+
+import (
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/spf13/viper"
+)
+
+// collectMapstructureKeys walks a config struct and returns every dotted key
+// viper would need in order to populate it.
+func collectMapstructureKeys(t reflect.Type, prefix string, out map[string]string) {
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		if field.PkgPath != "" {
+			continue // unexported
+		}
+		tag := field.Tag.Get("mapstructure")
+		name, _, _ := strings.Cut(tag, ",")
+		if name == "-" {
+			continue
+		}
+		if name == "" {
+			name = strings.ToLower(field.Name)
+		}
+		key := name
+		if prefix != "" {
+			key = prefix + "." + name
+		}
+
+		ft := field.Type
+		for ft.Kind() == reflect.Ptr {
+			ft = ft.Elem()
+		}
+		if ft.Kind() == reflect.Struct {
+			collectMapstructureKeys(ft, key, out)
+			continue
+		}
+		if ft.Kind() == reflect.Map {
+			// A map cannot be expressed in a single environment variable, so it
+			// is out of scope here — such settings need a config file either way.
+			continue
+		}
+		if ft.Kind() == reflect.Slice {
+			elem := ft.Elem()
+			for elem.Kind() == reflect.Ptr {
+				elem = elem.Elem()
+			}
+			if elem.Kind() == reflect.Struct {
+				// AutomaticEnv exposes one string value. Viper's string-to-slice
+				// hook can populate scalar slices, but it cannot decode a string
+				// into []struct. Registering a default would turn silent ignore
+				// into a startup unmarshal error, so structured slices remain
+				// config-file-only just like maps.
+				continue
+			}
+		}
+		out[strings.ToLower(key)] = ft.String()
+	}
+}
+
+// TestConfigKeysAreEnvReachable is the systemic guard behind the image_storage
+// bug: viper.Unmarshal only decodes keys returned by AllKeys(), which unions
+// SetDefault keys, config-file keys and explicit BindEnv keys. AutomaticEnv can
+// override a key already in that union but never introduces one, and the
+// viper_bind_struct escape hatch is compiled out (we build with -tags embed).
+//
+// So a Config field with no registered default is unreachable by environment
+// variable whenever the deployment has no config.yaml containing it — the
+// operator sets the variable, the loader discards it, and the feature behaves
+// as if it were never configured. That is exactly how image_storage credentials
+// were lost, silently disabling async image tasks for env-driven deployments.
+//
+// When this fails, register a zero-valued default in setEnvReachableDefaults
+// for each reported scalar key. Maps and slices of structs are config-file-only.
+func TestConfigKeysAreEnvReachable(t *testing.T) {
+	bound := map[string]string{}
+	collectMapstructureKeys(reflect.TypeOf(Config{}), "", bound)
+
+	viper.Reset()
+	t.Cleanup(viper.Reset)
+	setDefaults()
+	registered := map[string]struct{}{}
+	for _, key := range viper.AllKeys() {
+		registered[key] = struct{}{}
+	}
+
+	var unreachable []string
+	for key, kind := range bound {
+		if _, ok := registered[key]; !ok {
+			unreachable = append(unreachable, key+" ("+kind+")")
+		}
+	}
+	sort.Strings(unreachable)
+
+	if len(unreachable) > 0 {
+		t.Fatalf("%d config keys have no default registered, so their environment variables are silently ignored:\n  %s",
+			len(unreachable), strings.Join(unreachable, "\n  "))
+	}
+}