pages.clj

(defn iteration-op-map
  "Iterates an op-map based step. Useful in aws-api and gcp-api. Returns a list
  of results from each page after applying :itemsf. If an anomaly is returned
  from invoke-fn, it will be included in the list."
  [invoke-fn op-map {:keys [request-key response-key itemsf]}]
  (iteration
    (fn [next-token]
      (invoke-fn
        (cond-> op-map
          next-token (assoc-in [:request request-key] next-token))))
    :kf (fn [ret]
          (let [k (response-key ret)]
            (when (and k (if (string? k) (not (str/blank? k)) true))
              k)))
    :vf (fn [ret]
          (if (:cognitect.anomalies/category ret)
            ret
            (itemsf ret)))))

(comment
  (iteration-op-map
    #(aws/invoke client %)
    {:op      :ListObjectsV2
     :request {:Bucket "my-bucket"}}
    {:request-key  :ContinuationToken
     :response-key :ContinuationToken
     :itemsf       :Contents}))