Use strategy pattern-like switch to select vendor-specific handler

handlers/adfs/adfs.go

@@ -14,6 +14,8 @@ import (
 	"strings"
 )
 
+type Handler struct{}
+
 type adfsTokenRes struct {
 	AccessToken string `json:"access_token"`
 	TokenType   string `json:"token_type"`
@@ -26,7 +28,7 @@ var (
 )
 
 // More info: https://docs.microsoft.com/en-us/windows-server/identity/ad-fs/overview/ad-fs-scenarios-for-developers#supported-scenarios
-func GetUserInfoFromADFS(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
 	code := r.URL.Query().Get("code")
 	log.Debugf("code: %s", code)
 

handlers/github/github.go

@@ -11,14 +11,18 @@ import (
 	"strings"
 )
 
+type Handler struct {
+	PrepareTokensAndClient func(*http.Request, *structs.PTokens, bool) (error, *http.Client, *oauth2.Token)
+}
+
 var (
 	log = cfg.Cfg.Logger
 )
 
 // github
 // https://developer.github.com/apps/building-integrations/setting-up-and-registering-oauth-apps/about-authorization-options-for-oauth-apps/
-func GetUserInfoFromGitHub(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
-	err, client, ptoken := common.PrepareTokensAndClient(r, ptokens, true)
+func (me Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+	err, client, ptoken := me.PrepareTokensAndClient(r, ptokens, true)
 	if err != nil {
 		// http.Error(w, err.Error(), http.StatusBadRequest)
 		return err

handlers/github/github_test.go

@@ -2,15 +2,14 @@ package github
 
 import (
 	"encoding/json"
+	mockhttp "github.com/karupanerura/go-mock-http-response"
+	"github.com/stretchr/testify/assert"
 	"github.com/vouch/vouch-proxy/pkg/cfg"
 	"github.com/vouch/vouch-proxy/pkg/domains"
 	"github.com/vouch/vouch-proxy/pkg/structs"
 	"golang.org/x/oauth2"
 	"net/http"
 	"regexp"
-
-	mockhttp "github.com/karupanerura/go-mock-http-response"
-	"github.com/stretchr/testify/assert"
 	"testing"
 )
 
@@ -156,7 +155,7 @@ func TestGetOrgMembershipStateFromGitHubNoOrgAccess(t *testing.T) {
 	assertUrlCalled(t, expectedOrgPublicMembershipUrl)
 }
 
-func TestGetUserInfoFromGitHub(t *testing.T) {
+func TestGetUserInfo(t *testing.T) {
 	setUp()
 
 	userInfoContent, _ := json.Marshal(structs.GitHubUser{
@@ -178,7 +177,10 @@ func TestGetUserInfoFromGitHub(t *testing.T) {
 	mockResponse(regexMatcher(".*teams.*"), http.StatusOK, map[string]string{}, []byte("{\"state\": \"active\"}"))
 	mockResponse(regexMatcher(".*members.*"), http.StatusNoContent, map[string]string{}, []byte(""))
 
-	err := GetUserInfoFromGitHub(client, user, &structs.CustomClaims{}, token)
+	handler := Handler{PrepareTokensAndClient: func(_ *http.Request, _ *structs.PTokens, _ bool) (error, *http.Client, *oauth2.Token) {
+		return nil, client, token
+	}}
+	err := handler.GetUserInfo(nil, user, &structs.CustomClaims{}, &structs.PTokens{})
 
 	assert.Nil(t, err)
 	assert.Equal(t, "myusername", user.Username)

handlers/google/google.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 )
 
+type Handler struct{}
+
 var (
 	log = cfg.Cfg.Logger
 )
 
-func GetUserInfoFromGoogle(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
 	err, client, _ := common.PrepareTokensAndClient(r, ptokens, true)
 	if err != nil {
 		return err

handlers/handlers.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"fmt"
 	"github.com/vouch/vouch-proxy/handlers/adfs"
+	"github.com/vouch/vouch-proxy/handlers/common"
 	"github.com/vouch/vouch-proxy/handlers/github"
 	"github.com/vouch/vouch-proxy/handlers/google"
 	"github.com/vouch/vouch-proxy/handlers/homeassistant"
@@ -43,6 +44,10 @@ type AuthError struct {
 	JWT   string
 }
 
+type Handler interface {
+	GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) error
+}
+
 const (
 	base64Bytes = 32
 )
@@ -527,32 +532,30 @@ func CallbackHandler(w http.ResponseWriter, r *http.Request) {
 	renderIndex(w, "/auth "+tokenstring)
 }
 
-// TODO: put all getUserInfo logic into its own pkg
-
 func getUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) error {
+	return getHandler().GetUserInfo(r, user, customClaims, ptokens)
+}
 
-	// indieauth sends the "me" setting in json back to the callback, so just pluck it from the callback
-	if cfg.GenOAuth.Provider == cfg.Providers.IndieAuth {
-		return indieauth.GetUserInfoFromIndieAuth(r, user, customClaims, ptokens)
-	} else if cfg.GenOAuth.Provider == cfg.Providers.ADFS {
-		return adfs.GetUserInfoFromADFS(r, user, customClaims, ptokens)
-	}
-	if cfg.GenOAuth.Provider == cfg.Providers.HomeAssistant {
-		return homeassistant.GetUserInfoFromHomeAssistant(r, user, customClaims, ptokens)
-	}
-	if cfg.GenOAuth.Provider == cfg.Providers.OpenStax {
-		return openstax.GetUserInfoFromOpenStax(r, user, customClaims, ptokens)
-	}
-
-	if cfg.GenOAuth.Provider == cfg.Providers.Google {
-		return google.GetUserInfoFromGoogle(r, user, customClaims, ptokens)
-	} else if cfg.GenOAuth.Provider == cfg.Providers.GitHub {
-		return github.GetUserInfoFromGitHub(r, user, customClaims, ptokens)
-	} else if cfg.GenOAuth.Provider == cfg.Providers.OIDC {
-		return openid.GetUserInfoFromOpenID(r, user, customClaims, ptokens)
+func getHandler() Handler {
+	switch cfg.GenOAuth.Provider {
+	case cfg.Providers.IndieAuth:
+		return indieauth.Handler{}
+	case cfg.Providers.ADFS:
+		return adfs.Handler{}
+	case cfg.Providers.HomeAssistant:
+		return homeassistant.Handler{}
+	case cfg.Providers.OpenStax:
+		return openstax.Handler{}
+	case cfg.Providers.Google:
+		return google.Handler{}
+	case cfg.Providers.GitHub:
+		return github.Handler{common.PrepareTokensAndClient}
+	case cfg.Providers.OIDC:
+		return openid.Handler{}
+	default:
+		log.Error("we don't know how to look up the user info")
+		return nil
 	}
-	log.Error("we don't know how to look up the user info")
-	return nil
 }
 
 // the standard error

handlers/homeassistant/homeassistant.go

@@ -6,8 +6,10 @@ import (
 	"net/http"
 )
 
+type Handler struct{}
+
 // More info: https://developers.home-assistant.io/docs/en/auth_api.html
-func GetUserInfoFromHomeAssistant(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
 	err, _, providerToken := common.PrepareTokensAndClient(r, ptokens, false)
 	if err != nil {
 		return err

handlers/indieauth/indieauth.go

@@ -11,12 +11,14 @@ import (
 	"net/http"
 )
 
+type Handler struct{}
+
 var (
 	log = cfg.Cfg.Logger
 )
 
-func GetUserInfoFromIndieAuth(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
-
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+	// indieauth sends the "me" setting in json back to the callback, so just pluck it from the callback
 	code := r.URL.Query().Get("code")
 	log.Errorf("ptoken.AccessToken: %s", code)
 	var b bytes.Buffer

handlers/openid/openid.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 )
 
+type Handler struct{}
+
 var (
 	log = cfg.Cfg.Logger
 )
 
-func GetUserInfoFromOpenID(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
 	err, client, _ := common.PrepareTokensAndClient(r, ptokens, true)
 	if err != nil {
 		return err

handlers/openstax/openstax.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 )
 
+type Handler struct{}
+
 var (
 	log = cfg.Cfg.Logger
 )
 
-func GetUserInfoFromOpenStax(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
+func (Handler) GetUserInfo(r *http.Request, user *structs.User, customClaims *structs.CustomClaims, ptokens *structs.PTokens) (rerr error) {
 	err, client, _ := common.PrepareTokensAndClient(r, ptokens, false)
 	if err != nil {
 		return err