Given 2 parts of a url, join them with a slash if needed.
Source
static String joinWithSlash(String start, String end) {
if (start.length == 0) {
return end;
}
if (end.length == 0) {
return start;
}
var slashes = 0;
if (start.endsWith("/")) {
slashes++;
}
if (end.startsWith("/")) {
slashes++;
}
if (slashes == 2) {
return start + end.substring(1);
}
if (slashes == 1) {
return start + end;
}
return start + "/" + end;
}