feat: unify generated configuration loading and extensible decoders

cmd/go-omni/apigen/testdata/configuration/consumer_test.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"example.com/configuration/internal/config"
+	omniConfig "git.yuntuo.hk/k2safe/go-omni/config"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestGeneratedConfiguration(t *testing.T) {
+	for ext, source := range map[string]string{
+		"json": `{"limit":7}`, "yaml": "limit: 7\n", "xml": "<config><limit>7</limit></config>", "custom": `{"limit":7}`,
+	} {
+		t.Run(ext, func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), "app."+ext)
+			if err := os.WriteFile(path, []byte(source), 0600); err != nil {
+				t.Fatal(err)
+			}
+			cfg, err := config.Load(path)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if cfg.Limit != 7 {
+				t.Fatal(cfg.Limit)
+			}
+			t.Setenv("GO_OMNI_LIMIT", "0")
+			cfg, err = config.Load(path)
+			if err != nil || cfg.Limit != 0 {
+				t.Fatal(cfg.Limit, err)
+			}
+		})
+	}
+	t.Setenv("GO_OMNI_LOG_OUTPUT", "stderr")
+	cfg, err := config.Load("")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Limit != 10 || cfg.Server.Log.File != "" || cfg.Server.Log.Rotation.Enabled {
+		t.Fatal("defaults/log normalization", cfg, err)
+	}
+	path := filepath.Join(t.TempDir(), "bad.yaml")
+	os.WriteFile(path, []byte("limit: -1\n"), 0600)
+	// Validation must run before svc.Initialize; the project initializer panics
+	// below if reached, so this also detects accidentally starting dependencies.
+	err = run(context.Background(), path)
+	var diagnostic *omniConfig.Error
+	if !errors.As(err, &diagnostic) || diagnostic.Field != "limit" || diagnostic.File != path || diagnostic.Line != 1 {
+		t.Fatal(err)
+	}
+	t.Setenv("GO_OMNI_LIMIT", "private-not-a-number")
+	_, err = config.Load(path)
+	if !errors.As(err, &diagnostic) || diagnostic.Env != "GO_OMNI_LIMIT" || strings.Contains(err.Error(), "private-not-a-number") {
+		t.Fatal(err)
+	}
+}