func()

in google/google.go [149:210]

• 61 lines of code
• 11 McCabe index (conditional complexity)

func (f *credentialsFile) tokenSource(ctx context.Context, params CredentialsParams) (oauth2.TokenSource, error) {
	switch f.Type {
	case serviceAccountKey:
		cfg := f.jwtConfig(params.Scopes, params.Subject)
		return cfg.TokenSource(ctx), nil
	case userCredentialsKey:
		cfg := &oauth2.Config{
			ClientID:     f.ClientID,
			ClientSecret: f.ClientSecret,
			Scopes:       params.Scopes,
			Endpoint: oauth2.Endpoint{
				AuthURL:   f.AuthURL,
				TokenURL:  f.TokenURL,
				AuthStyle: oauth2.AuthStyleInParams,
			},
		}
		if cfg.Endpoint.AuthURL == "" {
			cfg.Endpoint.AuthURL = Endpoint.AuthURL
		}
		if cfg.Endpoint.TokenURL == "" {
			cfg.Endpoint.TokenURL = Endpoint.TokenURL
		}
		tok := &oauth2.Token{RefreshToken: f.RefreshToken}
		return cfg.TokenSource(ctx, tok), nil
	case externalAccountKey:
		cfg := &externalaccount.Config{
			Audience:                       f.Audience,
			SubjectTokenType:               f.SubjectTokenType,
			TokenURL:                       f.TokenURLExternal,
			TokenInfoURL:                   f.TokenInfoURL,
			ServiceAccountImpersonationURL: f.ServiceAccountImpersonationURL,
			ClientSecret:                   f.ClientSecret,
			ClientID:                       f.ClientID,
			CredentialSource:               f.CredentialSource,
			QuotaProjectID:                 f.QuotaProjectID,
			Scopes:                         params.Scopes,
			WorkforcePoolUserProject:       f.WorkforcePoolUserProject,
		}
		return cfg.TokenSource(ctx)
	case impersonatedServiceAccount:
		if f.ServiceAccountImpersonationURL == "" || f.SourceCredentials == nil {
			return nil, errors.New("missing 'source_credentials' field or 'service_account_impersonation_url' in credentials")
		}

		ts, err := f.SourceCredentials.tokenSource(ctx, params)
		if err != nil {
			return nil, err
		}
		imp := externalaccount.ImpersonateTokenSource{
			Ctx:       ctx,
			URL:       f.ServiceAccountImpersonationURL,
			Scopes:    params.Scopes,
			Ts:        ts,
			Delegates: f.Delegates,
		}
		return oauth2.ReuseTokenSource(nil, imp), nil
	case "":
		return nil, errors.New("missing 'type' field in credentials")
	default:
		return nil, fmt.Errorf("unknown credential type: %q", f.Type)
	}
}