Add clientapi tests (#2916)

This PR
- adds several tests for the clientapi, mostly around `/register` and
auth fallback.
- removes the now deprecated `homeserver` field from responses to
`/register` and `/login`
- slightly refactors auth fallback handling

2 files changed, 11 insertions, 8 deletions

diff --git a/setup/config/config.go b/setup/config/config.go
index 7e7ed1aa..6523a245 100644
--- a/setup/config/config.go
+++ b/setup/config/config.go
@@ -29,7 +29,7 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/crypto/ed25519"
-	yaml "gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v2"
 
 	jaegerconfig "github.com/uber/jaeger-client-go/config"
 	jaegermetrics "github.com/uber/jaeger-lib/metrics"
@@ -314,11 +314,13 @@ func (config *Dendrite) Derive() error {
 
 	if config.ClientAPI.RecaptchaEnabled {
 		config.Derived.Registration.Params[authtypes.LoginTypeRecaptcha] = map[string]string{"public_key": config.ClientAPI.RecaptchaPublicKey}
-		config.Derived.Registration.Flows = append(config.Derived.Registration.Flows,
-			authtypes.Flow{Stages: []authtypes.LoginType{authtypes.LoginTypeRecaptcha}})
+		config.Derived.Registration.Flows = []authtypes.Flow{
+			{Stages: []authtypes.LoginType{authtypes.LoginTypeRecaptcha}},
+		}
 	} else {
-		config.Derived.Registration.Flows = append(config.Derived.Registration.Flows,
-			authtypes.Flow{Stages: []authtypes.LoginType{authtypes.LoginTypeDummy}})
+		config.Derived.Registration.Flows = []authtypes.Flow{
+			{Stages: []authtypes.LoginType{authtypes.LoginTypeDummy}},
+		}
 	}
 
 	// Load application service configuration files
diff --git a/setup/config/config_clientapi.go b/setup/config/config_clientapi.go
index 0a871da1..11628b1b 100644
--- a/setup/config/config_clientapi.go
+++ b/setup/config/config_clientapi.go
@@ -78,9 +78,6 @@ func (c *ClientAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
 	c.TURN.Verify(configErrs)
 	c.RateLimiting.Verify(configErrs)
 	if c.RecaptchaEnabled {
-		checkNotEmpty(configErrs, "client_api.recaptcha_public_key", c.RecaptchaPublicKey)
-		checkNotEmpty(configErrs, "client_api.recaptcha_private_key", c.RecaptchaPrivateKey)
-		checkNotEmpty(configErrs, "client_api.recaptcha_siteverify_api", c.RecaptchaSiteVerifyAPI)
 		if c.RecaptchaSiteVerifyAPI == "" {
 			c.RecaptchaSiteVerifyAPI = "https://www.google.com/recaptcha/api/siteverify"
 		}
@@ -93,6 +90,10 @@ func (c *ClientAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
 		if c.RecaptchaSitekeyClass == "" {
 			c.RecaptchaSitekeyClass = "g-recaptcha-response"
 		}
+		checkNotEmpty(configErrs, "client_api.recaptcha_public_key", c.RecaptchaPublicKey)
+		checkNotEmpty(configErrs, "client_api.recaptcha_private_key", c.RecaptchaPrivateKey)
+		checkNotEmpty(configErrs, "client_api.recaptcha_siteverify_api", c.RecaptchaSiteVerifyAPI)
+		checkNotEmpty(configErrs, "client_api.recaptcha_sitekey_class", c.RecaptchaSitekeyClass)
 	}
 	// Ensure there is any spam counter measure when enabling registration
 	if !c.RegistrationDisabled && !c.OpenRegistrationWithoutVerificationEnabled {