Client Credentials

apps.go

@@ -94,3 +94,20 @@ func RegisterApp(ctx context.Context, appConfig *AppConfig) (*Application, error
 
 	return &app, nil
 }
+
+// ApplicationVerification is mastodon application.
+type ApplicationVerification struct {
+	Name     string `json:"name"`
+	Website  string `json:"website"`
+	VapidKey string `json:"vapid_key"`
+}
+
+// VerifyAppCredentials returns the mastodon application.
+func (c *Client) VerifyAppCredentials(ctx context.Context) (*ApplicationVerification, error) {
+	var application ApplicationVerification
+	err := c.doAPI(ctx, http.MethodGet, "/api/v1/apps/verify_credentials", nil, &application, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &application, nil
+}

apps_test.go

@@ -96,3 +96,49 @@ func TestRegisterAppWithCancel(t *testing.T) {
 		t.Fatalf("want %q but %q", want, err.Error())
 	}
 }
+
+func TestVerifyAppCredentials(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("Authorization") != "Bearer zoo" {
+			http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
+			return
+		}
+		if r.URL.Path != "/api/v1/apps/verify_credentials" {
+			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+			return
+		}
+		fmt.Fprintln(w, `{"name":"zzz","website":"yyy","vapid_key":"xxx"}`)
+	}))
+	defer ts.Close()
+
+	client := NewClient(&Config{
+		Server:       ts.URL,
+		ClientID:     "foo",
+		ClientSecret: "bar",
+		AccessToken:  "zip",
+	})
+	_, err := client.VerifyAppCredentials(context.Background())
+	if err == nil {
+		t.Fatalf("should be fail: %v", err)
+	}
+
+	client = NewClient(&Config{
+		Server:       ts.URL,
+		ClientID:     "foo",
+		ClientSecret: "bar",
+		AccessToken:  "zoo",
+	})
+	a, err := client.VerifyAppCredentials(context.Background())
+	if err != nil {
+		t.Fatalf("should not be fail: %v", err)
+	}
+	if a.Name != "zzz" {
+		t.Fatalf("want %q but %q", "zzz", a.Name)
+	}
+	if a.Website != "yyy" {
+		t.Fatalf("want %q but %q", "yyy", a.Name)
+	}
+	if a.VapidKey != "xxx" {
+		t.Fatalf("want %q but %q", "xxx", a.Name)
+	}
+}

mastodon.go

@@ -150,6 +150,18 @@ func (c *Client) Authenticate(ctx context.Context, username, password string) er
 	return c.authenticate(ctx, params)
 }
 
+// AuthenticateApp logs in using client credentials.
+func (c *Client) AuthenticateApp(ctx context.Context) error {
+	params := url.Values{
+		"client_id":     {c.Config.ClientID},
+		"client_secret": {c.Config.ClientSecret},
+		"grant_type":    {"client_credentials"},
+		"redirect_uri":  {"urn:ietf:wg:oauth:2.0:oob"},
+	}
+
+	return c.authenticate(ctx, params)
+}
+
 // AuthenticateToken logs in using a grant token returned by Application.AuthURI.
 //
 // redirectURI should be the same as Application.RedirectURI.

mastodon_test.go

@@ -144,6 +144,38 @@ func TestAuthenticateWithCancel(t *testing.T) {
 	}
 }
 
+func TestAuthenticateApp(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.FormValue("client_id") != "foo" || r.FormValue("client_secret") != "bar" {
+			http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
+			return
+		}
+		fmt.Fprintln(w, `{"name":"zzz","website":"yyy","vapid_key":"xxx"}`)
+		return
+	}))
+	defer ts.Close()
+
+	client := NewClient(&Config{
+		Server:       ts.URL,
+		ClientID:     "foo",
+		ClientSecret: "bat",
+	})
+	err := client.AuthenticateApp(context.Background())
+	if err == nil {
+		t.Fatalf("should be fail: %v", err)
+	}
+
+	client = NewClient(&Config{
+		Server:       ts.URL,
+		ClientID:     "foo",
+		ClientSecret: "bar",
+	})
+	err = client.AuthenticateApp(context.Background())
+	if err != nil {
+		t.Fatalf("should not be fail: %v", err)
+	}
+}
+
 func TestPostStatus(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Header.Get("Authorization") != "Bearer zoo" {