Make resp_link_url() case-insensitive (#655)

Fixes #654

Author: DavidRLovell

NEWS.md

@@ -1,5 +1,6 @@
 # httr2 (development version)
 
+* `resp_link_url()` once again ignores the case of headers (@DavidRLovell, #655)
 * `oauth_client()` and `oauth_token()` gain refreshed print methods that use bulleted lists, like other httr2 objects. Additionally, print a `oauth_client()` with a custom `auth` function no longer errors (#648).
 * `req_headers()` always redacts `Authorization` (#649).
 * `req_headers_redacted()` supports dynamic dots (#647)

R/resp-headers.R

@@ -174,7 +174,7 @@ resp_link_url <- function(resp, rel) {
   }
 
   headers <- resp_headers(resp)
-  link_headers <- headers[names(headers) == "Link"]
+  link_headers <- headers[tolower(names(headers)) == "link"]
   links <- unlist(lapply(link_headers, parse_link), recursive = FALSE)
   sel <- map_lgl(links, ~ .$rel == rel)
   if (sum(sel) != 1L) {

tests/testthat/test-resp-headers.R

@@ -46,6 +46,8 @@ test_that("can parse both forms of retry-after header", {
   expect_equal(resp_retry_after(resp_rel), NA)
 })
 
+# resp_link_url() --------------------------------------------------------------
+
 test_that("can extract specified link url", {
   resp <- response(headers = paste0(
     'Link: <https://example.com/1>; rel="next",',
@@ -67,3 +69,8 @@ test_that("can extract from multiple link headers", {
   expect_equal(resp_link_url(resp, "next"), "https://example.com/1")
   expect_equal(resp_link_url(resp, "last"), "https://example.com/2")
 })
+
+test_that("is case insensitive", {
+  resp <- response(headers = 'LINK: <https://example.com/1>; rel="next"')
+  expect_equal(resp_link_url(resp, "next"), "https://example.com/1")
+})