Append zero or more path elements to a URL without duplicating "/"
characters. Based on httr2::req_url_path_append()
.
Examples
url_path_append("https://example.com", "api", "v1", "users")
#> [1] "https://example.com/api/v1/users"
url_path_append("https://example.com/", "/api", "/v1", "/users")
#> [1] "https://example.com/api/v1/users"
url_path_append("https://example.com/", "/api/v1/users")
#> [1] "https://example.com/api/v1/users"