public({
  with_fake_http({
    test_that("expect_header with fake HTTP", {
      expect_GET(expect_success(expect_header(
        GET("http://httpbin.org/", config = add_headers(Accept = "image/jpeg")),
        "Accept: image/jpeg"
      )))
      # Because expect_header() raises warnings for headers and then catches
      # them, if the test expectation isn't met, the warning gets through.
      # Suppress that here so we aren't confused by it.
      suppressWarnings(
        expect_GET(expect_failure(
          expect_header(
            GET(
              "http://httpbin.org/",
              config = add_headers(Accept = "image/png")
            ),
            "Accept: image/jpeg"
          )
        ))
      )
      expect_POST(expect_success(expect_header(
        POST(
          "http://httpbin.org/",
          config = add_headers(Accept = "image/jpeg")
        ),
        "Accept: image/jpeg"
      )))
      suppressWarnings(
        expect_POST(expect_failure(
          expect_header(
            POST(
              "http://httpbin.org/",
              config = add_headers(Accept = "image/png")
            ),
            "Accept: image/jpeg"
          )
        ))
      )
    })
  })

  with_mock_api({
    test_that("expect_header with mock API", {
      expect_success(expect_header(
        GET("api/object1/", config = add_headers(Accept = "image/jpeg")),
        "Accept: image/jpeg"
      ))
      suppressWarnings(
        expect_failure(expect_header(
          GET("api/object1/", config = add_headers(Accept = "image/png")),
          "Accept: image/jpeg"
        ))
      )
      suppressWarnings(
        expect_POST(expect_success(expect_header(
          POST(
            "http://httpbin.org/",
            config = add_headers(Accept = "image/jpeg")
          ),
          "Accept: image/jpeg"
        )))
      )
      skip_if(third_edition)
      expect_failure(expect_header(
        expect_POST(
          POST(
            "http://httpbin.org/",
            config = add_headers(Accept = "image/png")
          ),
          silent = TRUE
        ),
        "Accept: image/jpeg"
      ))
    })
    test_that("expect_header ignore.case", {
      expect_success(expect_header(
        GET("api/object1/", config = add_headers(Accept = "image/jpeg")),
        "accept: image/jpeg"
      ))
      suppressWarnings(
        expect_failure(expect_header(
          GET("api/object1/", config = add_headers(Accept = "image/jpeg")),
          "accept: image/jpeg",
          ignore.case = FALSE
        ))
      )
    })
  })

  without_internet({
    test_that("expect_header without_internet", {
      expect_GET(expect_success(expect_header(
        GET("http://httpbin.org/", config = add_headers(Accept = "image/jpeg")),
        "Accept: image/jpeg"
      )))
      expect_GET(expect_warning(
        expect_failure(expect_header(
          GET(
            "http://httpbin.org/",
            config = add_headers(Accept = "image/png")
          ),
          "Accept: image/jpeg"
        )),
        "Accept: image/png"
      ))
    })
  })

  test_that("expect_header works with actual network too", {
    skip_if_disconnected()
    skip_on_ci()
    expect_success(expect_header(
      GET(
        "http://httpbin.org/get",
        config = add_headers(Accept = "image/jpeg")
      ),
      "Accept: image/jpeg"
    ))
    expect_failure(expect_warning(
      expect_header(
        GET(
          "http://httpbin.org/get",
          config = add_headers(Accept = "image/png")
        ),
        "Accept: image/jpeg"
      ),
      "Accept: image/png"
    ))
  })
})