stuarthalloway

(defn pull-many
  "Pull pattern from each entity in eids in a single eager query.
Returns a seqable of values sorted by:

sort-k            if sort-k non nil
eids order        if no sort-k specified
unsorted          if sort-k is nil"
  ([db pattern eids]
     (let [e->idx (into {} (map-indexed (fn [idx e] [e idx]) eids))]
       (pull-many db pattern #(-> % :db/id e->idx) eids)))

stuarthalloway

;; good repro #0: problem statement

;; in n takes (tricks: translate domain words into Datomic words, be precise.)
;; 0. "Two datoms in transaction conflict" move an entity id to a reference entity take 
;; 1. "Retracting an entity and adding an entity"
;; ...
;; 5. "Retracting a unique identity datom and asserting the same identity on another datom causes
;;    "2 datoms in transaction conflict"

;; good repro #1: depend only on Datomic API

stuarthalloway

(defn squuid-created-at
  "Pull the date back out of a squuid. This will be nonsense if the UUID
passed in was not a squuid!"
  [^java.util.UUID uuid]
  (let [secs (bit-shift-right (.getMostSignificantBits uuid) 32)]
    (java.util.Date. (* secs 1000))))

stuarthalloway

;; see also https://twitter.com/thing_umbrella/status/1111427898487898113
(require '[clojure.spec.alpha :as s])

;; spec that ensures the keys in renames match the keys in map
(s/def ::rename-keys-args
  (s/and (s/cat :map map? :renames map?)
         (fn [{:keys [map renames]}]
           (every? map (keys renames)))))

;; ok

stuarthalloway

(let [a 1 b])

Syntax error macroexpanding clojure.core/let at (REPL:5:1).
[a 1 b] - failed: even-number-of-forms? at: [:bindings] spec: :clojure.core.specs.alpha/bindings

stuarthalloway

;; compare to https://gist.github.com/lensgolda/13e549476fb65d3b8c2d71ca59b15937#file-test-clj

(require '[clojure.spec.alpha :as s])

;; general domain knowledge, not buried in a test
(s/def ::info (s/keys :req-un [::name]))
(s/def ::items (s/coll-of pos-int?))
(s/def ::active boolean?)

;; knowledge specific to this test data

stuarthalloway

(ns foo)
(defn hello [x] (str "Hi " x))
(ns bar)
(println (foo/hello "there"))
(remove-ns 'foo)
(println (resolve 'foo/hello))

stuarthalloway

(require
 '[clojure.main :as main]
 '[clojure.pprint :as pp])

(def strings
  "Some strings that should fail somewhere in read/compile"
  [":::5"
   "(let [x])"
   "(cond 1)"
   "defmulti 5 class)"

stuarthalloway

(->> [(cycle [:fizz :_ :_])
      (cycle [:buzz :_ :_ :_ :_])]
     (apply map vector)
     (take 25))

stuarthalloway

(comment "interop runtime exception repl-caught")
(/ 1 0)
ArithmeticException Divide by zero clojure.lang.Numbers.divide (Numbers.java:163)

(comment "interop runtime exception pst")
(pst)
ArithmeticException Divide by zero
	clojure.lang.Numbers.divide (Numbers.java:163)
	clojure.lang.Numbers.divide (Numbers.java:3833)
        ;; elided