tests/testthat/test-cache.R

In nealrichardson/httpcache: Query Cache for HTTP Clients

test_that("Cache is on by default", {
  expect_true(is.null(getOption("httpcache.on")))
  expect_true(caching())
})
test_that("httpcache.on option affects caching", {
  on.exit(options(httpcache.on = NULL))
  options(httpcache.on = FALSE)
  expect_false(caching())
  options(httpcache.on = TRUE)
  expect_true(caching())
})

public({
  clearCache()

  test_that("Cache gets set on GET", {
    expect_length(cacheKeys(), 0)
    with_fake_http({
      expect_GET(
        a <- GET("https://app.crunch.io/api/datasets"),
        "https://app.crunch.io/api/datasets"
      )
      expect_GET(
        b <- GET("https://app.crunch.io/api/", query = list(user = "me")),
        "https://app.crunch.io/api/?user=me"
      )
    })
    expect_length(cacheKeys(), 2)
    expect_true(hitCache("https://app.crunch.io/api/datasets"))
    expect_identical(a, getCache("https://app.crunch.io/api/datasets"))
  })

  without_internet({
    test_that("When the cache is set, can read from it even with no connection", {
      # Now read from cache
      expect_identical(
        GET("https://app.crunch.io/api/datasets")$url,
        "https://app.crunch.io/api/datasets"
      )
    })
    test_that("But uncached() prevents reading from the cache", {
      expect_error(
        uncached(GET("https://app.crunch.io/api/datasets")),
        "GET https://app.crunch.io/api/datasets"
      )
    })
  })

  test_that("PUT busts cache", {
    # Now bust cache
    with_fake_http({
      expect_PUT(
        PUT("https://app.crunch.io/api/datasets"),
        "https://app.crunch.io/api/datasets"
      )
    })
    # See that it's no longer in the cache
    expect_length(cacheKeys(), 1)
    without_internet({
      expect_error(
        GET("https://app.crunch.io/api/datasets"),
        "GET https://app.crunch.io/api/datasets"
      )
    })
  })

  test_that("PATCH busts cache", {
    without_internet({
      # It's in the cache
      expect_no_request(q <- GET("https://app.crunch.io/api/",
        query = list(user = "me")
      ))
      expect_identical(q$url, "https://app.crunch.io/api/?user=me")
      # Hey, let's try with the cache API
      expect_identical(getCache(buildCacheKey("https://app.crunch.io/api/",
        query = list(user = "me")
      )), q)
    })
    # Now bust cache
    with_fake_http({
      expect_PATCH(
        PATCH("https://app.crunch.io/api/"),
        "https://app.crunch.io/api/"
      )
    })
    # See that it's no longer in the cache
    expect_length(cacheKeys(), 0)
    without_internet({
      expect_GET(
        GET("https://app.crunch.io/api/", query = list(user = "me")),
        "https://app.crunch.io/api/?user=me"
      )
    })
  })

  test_that("POST busts cache more narrowly by default: setup", {
    with_fake_http({
      expect_GET(
        a <<- GET("https://app.crunch.io/api/datasets"),
        "https://app.crunch.io/api/datasets"
      )
      expect_GET(
        b <<- GET("https://app.crunch.io/api/", query = list(user = "me")),
        "https://app.crunch.io/api/?user=me"
      )
    })
  })
  without_internet({
    test_that("See that cache is set", {
      # Now read from cache
      expect_no_request(
        expect_identical(
          GET("https://app.crunch.io/api/datasets"),
          a
        )
      )
      expect_no_request(
        expect_identical(GET("https://app.crunch.io/api/",
          query = list(user = "me")
        ), b)
      )
    })
  })
  with_fake_http({
    test_that("POSTing to a different resource doesn't bust cache", {
      expect_POST(
        p1 <- POST("https://app.crunch.io/api/"),
        "https://app.crunch.io/api/"
      )
    })
  })
  without_internet({
    test_that("Cache was unaffected by that", {
      # Now read from cache
      expect_no_request(
        expect_identical(
          GET("https://app.crunch.io/api/datasets"),
          a
        )
      )
      expect_no_request(
        expect_identical(GET("https://app.crunch.io/api/",
          query = list(user = "me")
        ), b)
      )
    })
  })
  with_fake_http({
    test_that("POSTing busts cache narrowly", {
      expect_POST(
        p2 <- POST("https://app.crunch.io/api/datasets"),
        "https://app.crunch.io/api/datasets"
      )
    })
  })
  without_internet({
    test_that("Only that resource had its cache busted", {
      expect_GET(
        GET("https://app.crunch.io/api/datasets"),
        "https://app.crunch.io/api/datasets"
      )
      expect_no_request(
        expect_identical(GET("https://app.crunch.io/api/",
          query = list(user = "me")
        ), b)
      )
    })
  })

  test_that("cacheOff stops caching and clears existing cache", {
    clearCache() # So we're clean
    with_fake_http({
      expect_GET(GET("https://app.crunch.io/api/datasets"))
    })
    expect_length(cacheKeys(), 1)
    cacheOff()
    on.exit(cacheOn()) # Turn it back on
    expect_length(cacheKeys(), 0)
    with_fake_http({
      expect_GET(a <- GET("https://app.crunch.io/api/datasets"))
    })
    expect_length(cacheKeys(), 0)
    expect_identical(a$url, "https://app.crunch.io/api/datasets")
  })

  test_that("Requests with an invalid URL return a useful error", {
    expect_error(GET(NULL), "Invalid URL: NULL")
    expect_error(cachedPOST(table(1:5)),
      "Invalid URL: c(1, 1, 1, 1, 1)",
      fixed = TRUE
    )
    setClass("TestS4Obj", contains = "environment")
    expect_error(
      GET(new("TestS4Obj")),
      "Invalid URL.*TestS4Obj"
    )
  })
})