Add a function for cleanly merging URLs.

NAMESPACE

@@ -8,6 +8,7 @@ export(req_perform)
 export(req_prepare)
 export(security_api_key)
 export(stabilize_string)
+export(url_path_append)
 importFrom(fs,path)
 importFrom(httr2,req_perform)
 importFrom(rlang,":=")

R/utils.R

@@ -34,3 +34,31 @@ compact_nested_list <- function(lst) {
   }
   return(purrr::compact(lst))
 }
+
+#' Add path elements to a URL
+#'
+#' Append zero or more path elements to a URL without duplicating "/"
+#' characters. Based on [httr2::req_url_path_append()].
+#'
+#' @param url A URL to modify.
+#' @param ... Path elements to append, as strings.
+#'
+#' @return A modified URL.
+#' @export
+#'
+#' @examples
+#' url_path_append("https://example.com", "api", "v1", "users")
+#' url_path_append("https://example.com/", "/api", "/v1", "/users")
+#' url_path_append("https://example.com/", "/api/v1/users")
+url_path_append <- function(url, ...) {
+  url <- httr2::url_parse(url)
+  url$path <- .path_merge(url$path, ...)
+  return(httr2::url_build(url))
+}
+
+.path_merge <- function(...) {
+  path <- paste(c(...), collapse = "/")
+  path <- sub("^([^/])", "/\\1", path)
+  path <- gsub("/+", "/", path)
+  return(sub("/$", "", path))
+}

tests/testthat/test-req_query.R

@@ -13,7 +13,7 @@ test_that("req_prepare() uses query parameters", {
   )
 })
 
-test_that("req_prepare() smushes and concatenates multi-value query parameters", {
+test_that("req_prepare() smushes & concatenates multi-value query parameters", {
   test_result <- req_prepare(
     base_url = "https://example.com",
     query = list(

tests/testthat/test-utils.R

@@ -0,0 +1,15 @@
+test_that("Can build clean urls", {
+  expected_result <- "https://example.com/api/v1/users"
+  expect_identical(
+    url_path_append("https://example.com", "api", "v1", "users"),
+    expected_result
+  )
+  expect_identical(
+    url_path_append("https://example.com/", "/api", "/v1", "/users"),
+    expected_result
+  )
+  expect_identical(
+    url_path_append("https://example.com/", "/api/v1/users"),
+    expected_result
+  )
+})