Add domainHint parameter to Microsoft Connector (#2586)

Signed-off-by: Joe Knight <josephtknight@users.noreply.github.com>

connector/microsoft/microsoft.go

@@ -57,6 +57,7 @@ type Config struct {
 	// PromptType is used for the prompt query parameter.
 	// For valid values, see https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-auth-code-flow#request-an-authorization-code.
 	PromptType string `json:"promptType"`
+	DomainHint string `json:"domainHint"`
 }
 
 // Open returns a strategy for logging in through Microsoft.
@@ -75,6 +76,7 @@ func (c *Config) Open(id string, logger log.Logger) (connector.Connector, error)
 		logger:               logger,
 		emailToLowercase:     c.EmailToLowercase,
 		promptType:           c.PromptType,
+		domainHint:           c.DomainHint,
 	}
 	// By default allow logins from both personal and business/school
 	// accounts.
@@ -119,6 +121,7 @@ type microsoftConnector struct {
 	logger               log.Logger
 	emailToLowercase     bool
 	promptType           string
+	domainHint           string
 }
 
 func (c *microsoftConnector) isOrgTenant() bool {
@@ -160,6 +163,9 @@ func (c *microsoftConnector) LoginURL(scopes connector.Scopes, callbackURL, stat
 	if c.promptType != "" {
 		options = append(options, oauth2.SetAuthURLParam("prompt", c.promptType))
 	}
+	if c.domainHint != "" {
+		options = append(options, oauth2.SetAuthURLParam("domain_hint", c.domainHint))
+	}
 
 	return c.oauth2Config(scopes).AuthCodeURL(state, options...), nil
 }

connector/microsoft/microsoft_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"os"
 	"reflect"
 	"testing"
@@ -16,13 +17,68 @@ type testResponse struct {
 	data interface{}
 }
 
-const tenant = "9b1c3439-a67e-4e92-bb0d-0571d44ca965"
+const (
+	tenant   = "9b1c3439-a67e-4e92-bb0d-0571d44ca965"
+	clientID = "a115ebf3-6020-4384-8eb1-c0c42e667b6f"
+)
 
 var dummyToken = testResponse{data: map[string]interface{}{
 	"access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9",
 	"expires_in":   "30",
 }}
 
+func TestLoginURL(t *testing.T) {
+	testURL := "https://test.com"
+	testState := "some-state"
+
+	conn := microsoftConnector{
+		apiURL:      testURL,
+		graphURL:    testURL,
+		redirectURI: testURL,
+		clientID:    clientID,
+		tenant:      tenant,
+	}
+
+	loginURL, _ := conn.LoginURL(connector.Scopes{}, conn.redirectURI, testState)
+
+	parsedLoginURL, _ := url.Parse(loginURL)
+	queryParams := parsedLoginURL.Query()
+
+	expectEquals(t, parsedLoginURL.Path, "/"+tenant+"/oauth2/v2.0/authorize")
+	expectEquals(t, queryParams.Get("client_id"), clientID)
+	expectEquals(t, queryParams.Get("redirect_uri"), testURL)
+	expectEquals(t, queryParams.Get("response_type"), "code")
+	expectEquals(t, queryParams.Get("scope"), "user.read")
+	expectEquals(t, queryParams.Get("state"), testState)
+	expectEquals(t, queryParams.Get("prompt"), "")
+	expectEquals(t, queryParams.Get("domain_hint"), "")
+}
+
+func TestLoginURLWithOptions(t *testing.T) {
+	testURL := "https://test.com"
+	promptType := "consent"
+	domainHint := "domain.hint"
+
+	conn := microsoftConnector{
+		apiURL:      testURL,
+		graphURL:    testURL,
+		redirectURI: testURL,
+		clientID:    clientID,
+		tenant:      tenant,
+
+		promptType: promptType,
+		domainHint: domainHint,
+	}
+
+	loginURL, _ := conn.LoginURL(connector.Scopes{}, conn.redirectURI, "some-state")
+
+	parsedLoginURL, _ := url.Parse(loginURL)
+	queryParams := parsedLoginURL.Query()
+
+	expectEquals(t, queryParams.Get("prompt"), promptType)
+	expectEquals(t, queryParams.Get("domain_hint"), domainHint)
+}
+
 func TestUserIdentityFromGraphAPI(t *testing.T) {
 	s := newTestServer(map[string]testResponse{
 		"/v1.0/me?$select=id,displayName,userPrincipalName": {