api/auth: add ListTeams for auth.teams.list

auth.go

@@ -38,3 +38,27 @@ func (api *Client) SendAuthRevokeContext(ctx context.Context, token string) (*Au
 
 	return api.authRequest(ctx, "auth.revoke", values)
 }
+
+type listTeamsResponse struct {
+	Teams []Team `json:"teams"`
+	SlackResponse
+}
+
+// ListTeams returns all workspaces a token can access.
+func (api *Client) ListTeams() ([]Team, error) {
+	return api.ListTeamsContext(context.Background())
+}
+
+// ListTeams returns all workspaces a token can access with a custom context.
+func (api *Client) ListTeamsContext(ctx context.Context) ([]Team, error) {
+	values := url.Values{
+		"token": {api.token},
+	}
+
+	response := &listTeamsResponse{}
+	err := api.postMethod(ctx, "auth.teams.list", values, response)
+	if err != nil {
+		return nil, err
+	}
+	return response.Teams, response.Err()
+}

auth_test.go

@@ -0,0 +1,49 @@
+package slack
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func getTeamList(rw http.ResponseWriter, r *http.Request) {
+	rw.Header().Set("Content-Type", "application/json")
+	response := []byte(`{
+    "ok": true,
+    "teams": [
+        {
+            "name": "Shinichi's workspace",
+            "id": "T12345678"
+        },
+        {
+            "name": "Migi's workspace",
+            "id": "T12345679"
+        }
+    ],
+    "response_metadata": {
+        "next_cursor": "dXNlcl9pZDo5MTQyOTI5Mzkz"
+    }
+}`)
+	rw.Write(response)
+}
+
+func TestListTeams(t *testing.T) {
+	http.HandleFunc("/auth.teams.list", getTeamList)
+
+	once.Do(startServer)
+	api := New("testing-token", OptionAPIURL("http://"+serverAddr+"/"))
+
+	teams, err := api.ListTeams()
+	if err != nil {
+		t.Errorf("Unexpected error: %s", err)
+		return
+	}
+
+	assert.Len(t, teams, 2)
+	assert.Equal(t, "T12345678", teams[0].ID)
+	assert.Equal(t, "Shinichi's workspace", teams[0].Name)
+
+	assert.Equal(t, "T12345679", teams[1].ID)
+	assert.Equal(t, "Migi's workspace", teams[1].Name)
+}