Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/api4/cors_test.go

@@ -0,0 +1,154 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package api4
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/channels/store/storetest/mocks"
+)
+
+const (
+	acAllowOrigin      = "Access-Control-Allow-Origin"
+	acExposeHeaders    = "Access-Control-Expose-Headers"
+	acMaxAge           = "Access-Control-Max-Age"
+	acAllowCredentials = "Access-Control-Allow-Credentials"
+	acAllowMethods     = "Access-Control-Allow-Methods"
+	acAllowHeaders     = "Access-Control-Allow-Headers"
+)
+
+func TestCORSRequestHandling(t *testing.T) {
+	for name, testcase := range map[string]struct {
+		AllowCorsFrom            string
+		CorsExposedHeaders       string
+		CorsAllowCredentials     bool
+		ModifyRequest            func(req *http.Request)
+		ExpectedAllowOrigin      string
+		ExpectedExposeHeaders    string
+		ExpectedAllowCredentials string
+	}{
+		"NoCORS": {
+			"",
+			"",
+			false,
+			func(req *http.Request) {
+			},
+			"",
+			"",
+			"",
+		},
+		"CORSEnabled": {
+			"http://somewhere.com",
+			"",
+			false,
+			func(req *http.Request) {
+			},
+			"",
+			"",
+			"",
+		},
+		"CORSEnabledStarOrigin": {
+			"*",
+			"",
+			false,
+			func(req *http.Request) {
+				req.Header.Set("Origin", "http://pre-release.mattermost.com")
+			},
+			"*",
+			"",
+			"",
+		},
+		"CORSEnabledStarNoOrigin": { // CORS spec requires this, not a bug.
+			"*",
+			"",
+			false,
+			func(req *http.Request) {
+			},
+			"",
+			"",
+			"",
+		},
+		"CORSEnabledMatching": {
+			"http://mattermost.com",
+			"",
+			false,
+			func(req *http.Request) {
+				req.Header.Set("Origin", "http://mattermost.com")
+			},
+			"http://mattermost.com",
+			"",
+			"",
+		},
+		"CORSEnabledMultiple": {
+			"http://spinmint.com http://mattermost.com",
+			"",
+			false,
+			func(req *http.Request) {
+				req.Header.Set("Origin", "http://mattermost.com")
+			},
+			"http://mattermost.com",
+			"",
+			"",
+		},
+		"CORSEnabledWithCredentials": {
+			"http://mattermost.com",
+			"",
+			true,
+			func(req *http.Request) {
+				req.Header.Set("Origin", "http://mattermost.com")
+			},
+			"http://mattermost.com",
+			"",
+			"true",
+		},
+		"CORSEnabledWithHeaders": {
+			"http://mattermost.com",
+			"x-my-special-header x-blueberry",
+			true,
+			func(req *http.Request) {
+				req.Header.Set("Origin", "http://mattermost.com")
+			},
+			"http://mattermost.com",
+			"X-My-Special-Header, X-Blueberry",
+			"true",
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			th := SetupConfigWithStoreMock(t, func(cfg *model.Config) {
+				*cfg.ServiceSettings.AllowCorsFrom = testcase.AllowCorsFrom
+				*cfg.ServiceSettings.CorsExposedHeaders = testcase.CorsExposedHeaders
+				*cfg.ServiceSettings.CorsAllowCredentials = testcase.CorsAllowCredentials
+			})
+			defer th.TearDown()
+			licenseStore := mocks.LicenseStore{}
+			licenseStore.On("Get", "").Return(&model.LicenseRecord{}, nil)
+			th.App.Srv().Store().(*mocks.Store).On("License").Return(&licenseStore)
+
+			port := th.App.Srv().ListenAddr.Port
+			host := fmt.Sprintf("http://localhost:%v", port)
+			url := fmt.Sprintf("%v/api/v4/system/ping", host)
+
+			req, err := http.NewRequest("GET", url, nil)
+			require.NoError(t, err)
+			testcase.ModifyRequest(req)
+
+			client := &http.Client{}
+			resp, err := client.Do(req)
+			require.NoError(t, err)
+			assert.Equal(t, http.StatusOK, resp.StatusCode)
+			assert.Equal(t, testcase.ExpectedAllowOrigin, resp.Header.Get(acAllowOrigin))
+			assert.Equal(t, testcase.ExpectedExposeHeaders, resp.Header.Get(acExposeHeaders))
+			assert.Equal(t, "", resp.Header.Get(acMaxAge))
+			assert.Equal(t, testcase.ExpectedAllowCredentials, resp.Header.Get(acAllowCredentials))
+			assert.Equal(t, "", resp.Header.Get(acAllowMethods))
+			assert.Equal(t, "", resp.Header.Get(acAllowHeaders))
+		})
+	}
+}