feat: add basic structure of idp templates (#5053)

add basic structure and implement first providers for IDP templates to be able to manage and use them in the future

internal/idp/providers/github/github_test.go

@@ -0,0 +1,53 @@
+package github
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/zitadel/zitadel/internal/idp"
+	"github.com/zitadel/zitadel/internal/idp/providers/oauth"
+)
+
+func TestProvider_BeginAuth(t *testing.T) {
+	type fields struct {
+		clientID     string
+		clientSecret string
+		redirectURI  string
+		scopes       []string
+		options      []oauth.ProviderOpts
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		want   idp.Session
+	}{
+		{
+			name: "successful auth",
+			fields: fields{
+				clientID:     "clientID",
+				clientSecret: "clientSecret",
+				redirectURI:  "redirectURI",
+			},
+			want: &oauth.Session{
+				AuthURL: "https://github.com/login/oauth/authorize?client_id=clientID&redirect_uri=redirectURI&response_type=code&state=testState",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := assert.New(t)
+			r := require.New(t)
+
+			provider, err := New(tt.fields.clientID, tt.fields.clientSecret, tt.fields.redirectURI, tt.fields.scopes, tt.fields.options...)
+			r.NoError(err)
+
+			session, err := provider.BeginAuth(context.Background(), "testState")
+			r.NoError(err)
+
+			a.Equal(tt.want.GetAuthURL(), session.GetAuthURL())
+		})
+	}
+}