Option parsed options

option/internaloption/parsed_client_options.go

@@ -0,0 +1,38 @@
+// Copyright 2025 Google LLC.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+// Package internaloption contains options used internally by Google client code.
+package internaloption
+
+import (
+	"google.golang.org/api/internal"
+	"google.golang.org/api/option"
+)
+
+type ParsedOptions struct {
+	internal.DialSettings
+}
+
+// ParseClientOptions validates the given option.ClientOption slice and returns
+// ParsedOptions with the resolved settings. It returns an error if the
+// provided options are invalid.
+//
+// This function allows other Google Cloud client libraries to read configuration
+// values set by users via ClientOptions, which are otherwise unreadable outside of
+// google.golang.org/api.
+func ParseClientOptions(opts []option.ClientOption) (*ParsedOptions, error) {
+	var ds internal.DialSettings
+	// Apply all options to the internal DialSettings struct.
+	for _, opt := range opts {
+		opt.Apply(&ds)
+	}
+
+	// Validate the combined settings.
+	if err := ds.Validate(); err != nil {
+		return nil, err
+	}
+
+	return &ParsedOptions{
+		DialSettings: ds,
+	}, nil
+}

option/internaloption/parsed_client_options_test.go

@@ -0,0 +1,41 @@
+// Copyright 2025 Google LLC.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package internaloption
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/api/option"
+)
+
+func TestParseClientOptions(t *testing.T) {
+	testEndpoint := "test.example.com"
+	testAPIKey := "testAPIKey"
+	testScopes := []string{"scope1", "scope2"}
+
+	opts := []option.ClientOption{
+		option.WithEndpoint(testEndpoint),
+		option.WithAPIKey(testAPIKey),
+		option.WithScopes(testScopes...),
+	}
+	po, err := ParseClientOptions(opts)
+	if err != nil {
+		t.Fatalf("ParseClientOptions(%v) err = %v, want nil", opts, err)
+	}
+
+	if po.Endpoint != testEndpoint {
+		t.Errorf("po.Endpoint = %q, want %q", po.Endpoint, testEndpoint)
+	}
+	if po.APIKey != testAPIKey {
+		t.Errorf("po.APIKey = %q, want %q", po.APIKey, testAPIKey)
+	}
+	if !cmp.Equal(po.Scopes, testScopes) {
+		t.Errorf("po.Scopes diff (-got +want):\n%s", cmp.Diff(po.Scopes, testScopes))
+	}
+	if po.UserAgent != "" {
+		t.Errorf("po.UserAgent != nil, got %q", po.UserAgent)
+	}
+}