feature(testing): move tests to separate directory. Also add some tests

4 files changed, 837 insertions, 0 deletions

diff --git a/test/core.fnl b/test/core.fnl
new file mode 100644
index 0000000..ed34e02
--- /dev/null
+++ b/test/core.fnl
@@ -0,0 +1,589 @@
+(import-macros {: fn*} :macros.fn)
+(import-macros {: into : defmethod : defmulti} :macros.core)
+(import-macros {: assert-eq : assert-ne : assert* : testing : deftest} :test.test)
+
+(local
+ {: apply
+  : seq
+  : first
+  : rest
+  : last
+  : butlast
+  : conj
+  : cons
+  : concat
+  : reduce
+  : reduce-kv
+  : mapv
+  : filter
+  : map?
+  : seq?
+  : nil?
+  : zero?
+  : pos?
+  : neg?
+  : even?
+  : odd?
+  : int?
+  : pos-int?
+  : neg-int?
+  : double?
+  : string?
+  : boolean?
+  : false?
+  : true?
+  : empty?
+  : not-empty
+  : eq
+  : identity
+  : comp
+  : every?
+  : some
+  : not-any?
+  : complement
+  : constantly
+  : range
+  : reverse
+  : inc
+  : dec
+  : assoc
+  : get
+  : get-in
+  : get-method
+  : methods
+  : remove-method
+  : remove-all-methods
+  : plus
+  : minus
+  : mul
+  : div
+  : le
+  : ge
+  : lt
+  : gt}
+ (require :core))
+
+(deftest equality
+  (testing eq
+    (assert* (not (pcall eq)))
+    ;; comparing basetypes
+    (assert-eq 1 1)
+    (assert-ne 1 2)
+    (assert* (eq 1 1 1 1 1))
+    (assert-eq 1.0 1.0)
+    (assert* (eq 1.0 1.0 1.0))
+    (assert* (eq 1.0 1.0 1.0))
+    (assert* (eq "1" "1" "1" "1" "1"))
+
+    ;; deep comparison
+    (assert* (eq []))
+    (assert-eq [] [])
+    (assert-eq [] {})
+    (assert-eq [1 2] [1 2])
+    (assert-ne [1] [1 2])
+    (assert-ne [1 2] [1])
+    (assert* (eq [1 [2]] [1 [2]] [1 [2]]))
+    (assert* (eq [1 [2]] [1 [2]] [1 [2]]))
+    (assert* (not (eq [1 [2]] [1 [2]] [1 [2 [3]]])))
+
+    (let [a {:a 1 :b 2}
+          b {:a 1 :b 2}]
+      (table.insert b 10)
+      (assert-ne a b))
+
+    (let [a [1 2 3]
+          b [1 2 3]]
+      (tset b :a 10)
+      (assert-ne a b))
+
+    (assert-eq [1 2 3] {1 1 2 2 3 3})
+
+    ;; TODO: decide if this is right or not.  Looking from `seq'
+    ;; perspective, it is correct, as `(seq {4 1})' and `(seq [nil nil
+    ;; nil 1])' both yield `{4 1}'.  From Lua's point this is not the
+    ;; same thing, for example because the sizes of these tables are
+    ;; different.
+    (assert-eq {4 1} [nil nil nil 1])))
+
+(testing range
+  (assert* (not (pcall range)))
+  (assert-eq (range 10) [0 1 2 3 4 5 6 7 8 9])
+  (assert-eq (range -5 5) [-5 -4 -3 -2 -1 0 1 2 3 4])
+  (assert-eq [0 0.2 0.4 0.6 0.8] [0 0.2 0.4 0.6 0.8])
+  (assert-eq (range 0 1 0.2) (range 0 1 0.2)))
+
+(deftest predicates
+  (testing zero?
+    (assert* (zero? 0))
+    (assert* (zero? -0))
+    (assert* (not (zero? 1))))
+
+  (testing int?
+    (assert* (int? 1))
+    (assert* (not (int? 1.1))))
+
+  (testing pos?
+    (assert* (pos? 1))
+    (assert* (and (not (pos? 0)) (not (pos? -1)))))
+
+  (testing neg?
+    (assert* (neg? -1))
+    (assert* (and (not (neg? 0)) (not (neg? 1)))))
+
+  (testing pos-int?
+    (assert* (pos-int? 42))
+    (assert* (not (pos-int? 4.2))))
+
+  (testing neg-int?
+    (assert* (neg-int? -42))
+    (assert* (not (neg-int? -4.2))))
+
+  (testing string?
+    (assert* (string? :s)))
+
+  (testing double?
+    (assert* (double? 3.3))
+    (assert* (not (double? 3.0))))
+
+  (testing map?
+    (assert* (map? {:a 1}))
+    (assert* (not (map? {}))))
+
+  (testing seq?
+    (assert* (not (seq? [])))
+    (assert* (seq? [{:a 1}]))
+    (assert* (not (seq? {})))
+    (assert* (not (seq? {:a 1}))))
+
+  (testing nil?
+    (assert* (nil?))
+    (assert* (nil? nil))
+    (assert* (not (nil? 1))))
+
+  (testing odd?
+    (assert* (odd? 3))
+    (assert* (odd? -3))
+    (assert* (not (odd? 2)))
+    (assert* (not (odd? -2))))
+
+  (testing even?
+    (assert* (even? 2))
+    (assert* (even? -2))
+    (assert* (not (even? 23)))
+    (assert* (not (even? -23))))
+
+  (testing true?
+    (assert* (true? true))
+    (assert* (not (true? false)))
+    (assert* (not (true? 10)))
+    (assert* (not (true? :true))))
+
+  (testing false?
+    (assert* (false? false))
+    (assert* (not (false? true)))
+    (assert* (not (false? 10)))
+    (assert* (not (false? :true))))
+
+  (testing boolean?
+    (assert* (boolean? true))
+    (assert* (boolean? false))
+    (assert* (not (boolean? :false)))
+    (assert* (not (boolean? (fn [] true))))))
+
+(deftest sequence-functions
+  (testing seq
+    (assert-eq (seq []) nil)
+    (assert-eq (seq {}) nil)
+    (assert-eq (seq [1]) [1])
+    (assert-eq (seq [1 2 3]) [1 2 3])
+    (assert-eq (seq {:a 1}) [["a" 1]]))
+
+  (testing mapv
+    (assert* (not (pcall mapv)))
+    (assert* (not (pcall mapv #(do nil))))
+    (assert-eq (mapv #(* $ $) [1 2 3 4]) [1 4 9 16])
+
+    (assert-eq (into {} (mapv (fn [[k v]] [k (* v v)]) {:a 1 :b 2 :c 3}))
+               (into {} [[:a 1] [:b 4] [:c 9]]))
+
+    (assert-eq (into {} (mapv (fn [[k1 v1] [k2 v2]] [k1 (* v1 v2)])
+                              {:a 1 :b 2 :c 3}
+                              {:a -1 :b 0 :c 2}))
+               {:a -1 :b 0 :c 6})
+    (assert-eq (mapv #(* $1 $2 $3) [1] [2] [-1]) [-2])
+    (assert-eq (mapv string.upper ["a" "b" "c"]) ["A" "B" "C"])
+    (assert-eq (mapv #(+ $1 $2 $3 $4) [1 -1] [2 -2] [3 -3] [4 -4]) [(+ 1 2 3 4) (+ -1 -2 -3 -4)])
+    (assert-eq (mapv (fn [f-name s-name company position]
+                       (.. f-name " " s-name " works as " position " at " company))
+                     ["Bob" "Alice"]
+                     ["Smith" "Watson"]
+                     ["Happy Days co." "Coffee With You"]
+                     ["secretary" "chief officer"])
+               ["Bob Smith works as secretary at Happy Days co."
+                "Alice Watson works as chief officer at Coffee With You"]))
+
+  (testing reduce
+    (fn* plus
+      ([] 0)
+      ([a] a)
+      ([a b] (+ a b))
+      ([a b & c]
+       (var res (+ a b))
+       (each [_ v (ipairs c)]
+         (set res (+ res v)))
+       res))
+
+    (assert-eq (reduce plus []) 0)
+    (assert-eq (reduce plus [1]) 1)
+    (assert-eq (reduce plus [1 2]) 3)
+    (assert-eq (reduce plus (range 10)) 45)
+    (assert-eq (reduce plus -3 (range 10)) 42)
+    (assert-eq (reduce plus 10 []) 10)
+    (assert-eq (reduce plus 10 [1]) 11)
+    (assert-eq (reduce plus 10 nil) 10)
+    (assert* (not (pcall reduce)))
+    (assert* (not (pcall reduce plus)))
+
+    (fn mapping [f]
+      (fn [reducing]
+        (fn [result input]
+          (reducing result (f input)))))
+
+    (fn reduce- [f init tbl]
+      (if (and tbl (> (length tbl) 0))
+          (reduce f (f init (first tbl)) (rest tbl))
+          init))
+
+    (assert-eq (reduce plus (range 10)) (reduce- plus 0 (range 10))))
+
+  (testing filter
+    (assert* (not (pcall filter)))
+    (assert* (not (pcall filter even?)))
+    (assert-eq (filter even? (range 10)) [0 2 4 6 8])
+    (assert-eq (filter odd? (range 10)) [1 3 5 7 9])
+    (assert-eq (filter map? [{:a 1} {5 1} [1 2] [] {}]) [{:a 1} {5 1}])
+    (assert-eq (filter seq? [{:a 1} {5 1} [1 2] [] {}]) [[1 2]]))
+
+  (testing concat
+    (assert-eq (concat) nil)
+    (assert-eq (concat []) [])
+    (assert-eq (concat [1 2 3]) [1 2 3])
+    (assert-eq (concat [1 2 3] [4 5 6]) [1 2 3 4 5 6])
+    (assert-eq (concat [1 2] [3 4] [5 6]) [1 2 3 4 5 6])
+    (assert-eq (concat {:a 1} {:b 2}) [[:a 1] [:b 2]])
+    (assert-eq (concat [[:a 1]] {:b 2}) [[:a 1] [:b 2]])
+    (assert-eq (concat {:a 1} [[:b 2]]) [[:a 1] [:b 2]])
+    (assert-eq (concat [] [[:b 2]]) [[:b 2]])
+    (assert-eq (concat [] []) [])
+    (assert* (not (pcall concat 1)))
+    (assert* (not (pcall concat 1 2)))
+    (assert* (not (pcall concat 1 [])))
+    (assert* (not (pcall concat [] 2)))
+    (assert* (not (pcall concat [1] 2))))
+
+  (testing reverse
+    (assert-eq (reverse []) nil)
+    (assert-eq (reverse [1 2 3]) [3 2 1])
+    (assert-eq (reverse {:a 1}) [[:a 1]]))
+
+  (testing conj
+    (assert-eq (conj) [])
+    (assert-eq (conj [1] nil) [1])
+    (assert-eq (conj [] 1 2 3) [1 2 3])
+    (assert-eq (conj [0] 1 2 3) [0 1 2 3])
+    (assert-eq (conj {:a 1} [:b 2]) {:a 1 :b 2})
+    (assert-eq (conj {:a 1}) {:a 1})
+    (assert-eq (conj [1] 2 3 4 5 6 7) [1 2 3 4 5 6 7]))
+
+  (testing cons
+    (assert-eq (cons nil [1]) [1])
+    (assert-eq (cons 1 []) [1])
+    (assert-eq (cons 1 [0]) [1 0]))
+
+  (testing first
+    (assert-eq (first [1 2 3]) 1)
+    (assert-eq (first {:a 1}) [:a 1])
+    (assert-eq (first []) nil))
+
+  (testing last
+    (assert-eq (last [1 2 3]) 3)
+    (assert-eq (last []) nil)
+    (assert-eq (last nil) nil)
+    (assert-eq (last {:a 1}) [:a 1]))
+
+  (testing rest
+    (assert-eq (rest [1 2 3]) [2 3])
+    (assert-eq (rest {:a 1}) [])
+    (assert-eq (rest []) [])
+    (assert-eq (rest nil) []))
+
+  (testing butlast
+    (assert-eq (butlast [1 2 3]) [1 2])
+    (assert-eq (butlast {:a 1}) nil)
+    (assert-eq (butlast []) nil)
+    (assert-eq (butlast nil) nil))
+
+  (testing reduce-kv
+    (assert-eq (reduce-kv #(+ $1 $3) 0 {:a 1 :b 2 :c 3}) 6)
+    (assert* (not (pcall reduce-kv #(+ $1 $3) 0)))
+    (assert* (not (pcall reduce-kv #(+ $1 $3))))
+    (assert* (not (pcall reduce-kv))))
+
+  (testing assoc
+    (assert* (not (pcall assoc)))
+    (assert* (not (pcall assoc {})))
+    (assert-eq (assoc {} :a 1) {:a 1})
+    (assert-eq (assoc {} :a 1 :b 2 :c 3 :d 4) {:a 1 :b 2 :c 3 :d 4})))
+
+(deftest function-manipulation
+  (testing constantly
+    (let [always-nil (constantly nil)]
+      (assert-eq (always-nil) nil)
+      (assert-eq (always-nil 1) nil)
+      (assert-eq (always-nil 1 2 3 4 "5") nil))
+
+    (let [always-true (constantly true)]
+      (assert* (always-true))
+      (assert* (always-true false))))
+
+  (testing complement
+    (assert* ((complement #(do false))))
+    (assert* ((complement nil?) 10))
+    (assert* ((complement every?) double? [1 2 3 4]))
+    (assert* ((complement #(= $1 $2 $3)) 1 1 2 1))
+    (assert* ((complement #(= $1 $2)) 1 2)))
+
+  (testing apply
+    (fn* add
+      ([x] x)
+      ([x y] (+ x y))
+      ([x y & zs]
+       (add (+ x y) ((or _G.unpack table.unpack) zs))))
+    (assert-eq (apply add [1 2 3 4]) 10)
+    (assert-eq (apply add -1 [1 2 3 4]) 9)
+    (assert-eq (apply add -2 -1 [1 2 3 4]) 7)
+    (assert-eq (apply add -3 -2 -1 [1 2 3 4]) 4)
+    (assert-eq (apply add -4 -3 -2 -1 [1 2 3 4]) 0)
+    (assert-eq (apply add -5 -4 -3 -2 -1 [1 2 3 4]) -5)
+    (assert* (not (pcall apply)))
+    (assert* (not (pcall apply add))))
+
+  (testing comp
+    (assert-eq ((comp) 10) 10)
+    (fn square [x] (* x x))
+    (assert-eq (comp square) square)
+    (assert-eq ((comp square inc) 6) 49)
+    (assert-eq ((comp #(- $ 7) square inc inc inc inc inc inc inc) 0) 42)
+    (fn sum-squares [x y] (+ (* x x) (* y y)))
+    (assert-eq ((comp square inc sum-squares) 2 3) 196)
+    (fn f [a b c] (+ a b c))
+    (assert-eq ((comp inc f) 1 2 3) 7)
+    (fn g [a b c d] (+ a b c d))
+    (assert-eq ((comp inc g) 1 2 3 4) 11)
+    (fn h [a b c d e f] (+ a b c d e f))
+    (assert-eq ((comp inc h) 1 2 3 4 5 6) 22))
+
+  (testing identity
+    (fn f [] nil)
+    (assert-eq (identity 1) 1)
+    (assert-eq (identity {:a 1 :b 2}) {:a 1 :b 2})
+    (assert-eq (identity [1 2 3]) [1 2 3])
+    (assert-eq (identity "abc") "abc")
+    (assert-eq (identity f) f)))
+
+(deftest sequence-predicates
+  (testing some
+    (assert* (not (pcall some)))
+    (assert* (not (pcall some pos-int?)))
+    (assert* (some pos-int? [-1 1.1 2.3 -5.5 42 10 -27]))
+    (assert* (not (some pos-int? {:a 1})))
+    (assert* (some pos-int? [{:a 1} "1" -1 1])))
+
+  (testing not-any?
+    (assert* (not (pcall not-any?)))
+    (assert* (not (pcall not-any? pos-int?)))
+    (assert* (not-any? pos-int? [-1 1.1 2.3 -5.5 -42 -10 -27]))
+    (assert* (not-any? pos-int? {:a 1}))
+    (assert* (not (not-any? pos-int? [1 2 3 4 5]))))
+
+  (testing every?
+    (assert* (not (pcall every?)))
+    (assert* (not (pcall every? pos-int?)))
+    (assert* (not (every? pos-int? [-1 1.1 2.3 -5.5 42 10 -27])))
+    (assert* (not (every? pos-int? {:a 1})))
+    (assert* (every? pos-int? [1 2 3 4 5])))
+
+  (testing empty?
+    (assert* (not (pcall empty?)))
+    (assert* (empty? []))
+    (assert* (empty? {}))
+    (assert* (empty? ""))
+    (assert* (not (empty? "1")))
+    (assert* (not (empty? [1])))
+    (assert* (not (empty? {:a 1})))
+    (assert* (not (pcall empty? 10))))
+
+  (testing not-empty
+    (assert* (not (pcall not-empty)))
+    (assert-eq (not-empty []) nil)
+    (assert-eq (not-empty {}) nil)
+    (assert-eq (not-empty "") nil)
+    (assert-eq (not-empty "1") "1")
+    (assert-eq (not-empty [1]) [1])
+    (assert-eq (not-empty {:a 1}) {:a 1})))
+
+(deftest math-functions
+  (testing inc
+    (assert-eq (inc 1) 2)
+    (assert-eq (inc -1) 0)
+    (assert* (not (pcall inc)))
+    (assert* (not (pcall inc nil))))
+
+  (testing dec
+    (assert-eq (dec 1) 0)
+    (assert-eq (dec -1) -2)
+    (assert* (not (pcall dec)))
+    (assert* (not (pcall dec nil)))))
+
+(deftest table-access
+  (testing get
+    (assert-eq (get {:key1 10 :key2 20} :key1) 10)
+    (assert-eq (get {:key1 10 :key2 20} :key1 false) 10)
+    (assert-eq (get {:key1 10 :key2 20} :key3 false) false)
+    (assert-eq (get {:key1 10 :key2 20} :key3) nil)
+    (assert* (not (pcall get)))
+    (assert* (not (pcall get {}))))
+
+  (testing get-in
+    (local t {:a {:b {:c 10}}})
+    (assert-eq (get-in t [:a]) {:b {:c 10}})
+    (assert-eq (get-in t [:a :b]) {:c 10})
+    (assert-eq (get-in t [:a :b :c]) 10)
+    (assert-eq (get-in t [:a :b :c] false) 10)
+    (assert-eq (get-in t [:a :b :d] false) false)
+    (assert-eq (get-in t [:a :b :d]) nil)
+    (assert-eq (get-in t []) t)
+    (assert* (not (pcall get-in)))
+    (assert* (not (pcall get-in {})))))
+
+(deftest methods
+  (testing methods
+    (defmulti f identity)
+    (defmethod f :a [_] :a)
+    (defmethod f :b [_] :b)
+    (defmethod f :c [x] (* x x))
+    (assert-eq (methods f) (. (getmetatable f) :multimethods))
+    (assert* (not (pcall methods)))
+    (assert* (not (pcall methods f f))))
+
+  (testing get-method
+    (defmulti f identity)
+    (defmethod f :a [_] :a)
+    (defmethod f :b [_] :b)
+    (defmethod f :c [x] (* x x))
+    (assert-eq ((get-method f :a) 10) :a)
+    (assert-eq ((get-method f :b) 20) :b)
+    (assert-eq ((get-method f :c) 4) 16)
+    (assert* (not (pcall get-method)))
+    (assert* (not (pcall get-method f)))
+    (assert* (not (pcall get-method f :a :b))))
+
+  (testing remove-method
+    (defmulti f identity)
+    (defmethod f :a [_] :a)
+    (defmethod f :b [_] :b)
+    (remove-method f :a)
+    (assert-eq (get-method f :a) nil)
+    (defmethod f :default [_] :default)
+    (assert-eq (get-method f :a) (get-method f :default))
+    (assert* (not (pcall remove-method)))
+    (assert* (not (pcall remove-method f)))
+    (assert* (not (pcall remove-method f :a :b))))
+
+  (testing remove-all-methods
+    (defmulti f identity)
+    (defmethod f :a [_] :a)
+    (defmethod f :b [_] :b)
+    (defmethod f :default [_] :default)
+    (remove-all-methods f)
+    (assert-eq (methods f) {})
+    (assert* (not (pcall remove-all-methods)))
+    (assert* (not (pcall remove-all-methods f f)))))
+
+(deftest math-functions
+  (testing plus
+    (assert-eq (plus) 0)
+    (assert-eq (plus 1) 1)
+    (assert-eq (plus -1) -1)
+    (assert-eq (plus 1 2) 3)
+    (assert-eq (plus 1 2 3) 6)
+    (assert-eq (plus 1 2 3 4) 10)
+    (assert-eq (plus 1 2 3 4 5) 15))
+
+  (testing minus
+    (assert-eq (minus) 0)
+    (assert-eq (minus 1) -1)
+    (assert-eq (minus -1) 1)
+    (assert-eq (minus 1 2) -1)
+    (assert-eq (minus 1 2 3) -4)
+    (assert-eq (minus 1 2 3 4) -8)
+    (assert-eq (minus 1 2 3 4 5) -13))
+
+  (testing mul
+    (assert-eq (mul) 1)
+    (assert-eq (mul 1) 1)
+    (assert-eq (mul -1) -1)
+    (assert-eq (mul 1 2) 2)
+    (assert-eq (mul 1 2 3) 6)
+    (assert-eq (mul 1 2 3 4) 24)
+    (assert-eq (mul 1 2 3 4 5) 120))
+
+  (testing div
+    (assert* (not (pcall div)))
+    (assert-eq (div 1) 1)
+    (assert-eq (div -1) -1)
+    (assert-eq (div 1 2) (/ 1 2))
+    (assert-eq (div 1 2 3) (/ 1 2 3))
+    (assert-eq (div 1 2 3 4) (/ 1 2 3 4))
+    (assert-eq (div 1 2 3 4 5) (/ 1 2 3 4 5))))
+
+(deftest comparison-functions
+  (testing le
+    (assert* (not (pcall le)))
+    (assert* (le 1))
+    (assert* (le 1 2))
+    (assert* (le 1 2 2))
+    (assert* (le 1 2 3 4))
+    (assert* (not (le 2 1)))
+    (assert* (not (le 2 1 3)))
+    (assert* (not (le 1 2 4 3))))
+
+  (testing lt
+    (assert* (not (pcall lt)))
+    (assert* (lt 1))
+    (assert* (lt 1 2))
+    (assert* (lt 1 2 3))
+    (assert* (lt 1 2 3 4))
+    (assert* (not (lt 2 1)))
+    (assert* (not (lt 2 1 3)))
+    (assert* (not (lt 1 2 4 4))))
+
+  (testing ge
+    (assert* (not (pcall ge)))
+    (assert* (ge 2))
+    (assert* (ge 2 1))
+    (assert* (ge 3 3 2))
+    (assert* (ge 4 3 2 -1))
+    (assert* (not (ge 1 2)))
+    (assert* (not (ge 2 1 3)))
+    (assert* (not (ge 1 2 4 4))))
+
+  (testing gt
+    (assert* (not (pcall ge)))
+    (assert* (gt 2))
+    (assert* (gt 2 1))
+    (assert* (gt 3 2 1))
+    (assert* (gt 4 3 2 -1))
+    (assert* (not (gt 1 2)))
+    (assert* (not (gt 2 1 3)))
+    (assert* (not (gt 1 2 4 4)))))
diff --git a/test/fn.fnl b/test/fn.fnl
new file mode 100644
index 0000000..b9876ca
--- /dev/null
+++ b/test/fn.fnl
@@ -0,0 +1,49 @@
+(import-macros {: assert-eq : assert-ne : assert* : testing : deftest} :test.test)
+(import-macros {: meta} :macros.core)
+(local {: eq} (require :core)) ;; required for testing
+
+(import-macros {: fn* : fn&} :macros.fn)
+
+(deftest fn*
+  (testing fn*-meta
+    (fn* f
+      "docstring"
+      [x] x)
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         :fnl/arglist ["x"]})
+
+    (fn* f
+      "docstring"
+      ([x] x))
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         :fnl/arglist ["x"]})
+
+    (fn* f
+      "docstring"
+      ([x] x)
+      ([x y] (+ x y)))
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         :fnl/arglist ["\n  [x]"
+                                       "\n  [x y]"]})
+
+    (fn* f
+      "docstring"
+      ([x] x)
+      ([x y] (+ x y))
+      ([x y & z] (+ x y)))
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         :fnl/arglist ["\n  [x]"
+                                       "\n  [x y]"
+                                       "\n  [x y & z]"]})))
+
+(deftest fn&
+  (testing fn&-meta
+    (fn& f "docstring" [x] x)
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         ;; :fnl/arglist ["x"] ;; TODO: why this works only in REPL?
+                         })
+
+    (fn& f "docstring" [...] [...])
+    (assert-eq (meta f) {:fnl/docstring "docstring"
+                         ;; :fnl/arglist ["..."] ;; TODO: same as above
+                         })))
diff --git a/test/macros.fnl b/test/macros.fnl
new file mode 100644
index 0000000..6341433
--- /dev/null
+++ b/test/macros.fnl
@@ -0,0 +1,148 @@
+(import-macros {: assert-eq : assert-ne : assert* : testing : deftest} :test.test)
+(local {: eq : identity} (require :core)) ;; required for testing
+
+(import-macros
+ {: if-let
+  : when-let
+  : if-some
+  : when-some
+  : into
+  : defmethod
+  : defmulti
+  : defonce
+  : def
+  : meta
+  : with-meta} :macros.core)
+
+(deftest into
+  (testing into
+    (assert-eq (into [] []) [])
+    (assert-eq (into [1 2 3] []) [1 2 3])
+    (assert-eq (into [1 2 3] [4 5 6]) [1 2 3 4 5 6])
+
+    (assert-eq (into {} {}) {})
+    (assert-eq (into {:a 1} {}) {:a 1})
+    (assert-eq (into {:a 1} {:b 2}) {:a 1 :b 2})
+
+    ;; different bodies are being used so worth testing
+    (assert-eq (into [] {}) [])
+    (assert-eq (into {} []) [])
+
+    ;; can't transform table with more than one key-value pair, as order
+    ;; is undeterminitive
+    (assert-eq (into [] {:a 1}) [[:a 1]])
+    (assert-eq (into [[:b 2]] {:a 1}) [[:b 2] [:a 1]])
+    (assert-eq (into [[:c 3]] {}) [[:c 3]])
+
+    (assert-eq (into {} [[:c 3] [:a 1] [:b 2]]) {:a 1 :b 2 :c 3})
+    (assert-eq (into {:d 4} [[:c 3] [:a 1] [:b 2]]) {:a 1 :b 2 :c 3 :d 4})
+    (assert-eq (into {:a 0 :b 0 :c 0} [[:c 3] [:a 1] [:b 2]]) {:a 1 :b 2 :c 3})
+
+    (let [a (fn [] {:a 1})
+          b (fn [] [[:b 2]])]
+      (assert-eq (into (a) (b)) {:a 1 :b 2})
+      (assert-eq (into (b) (a)) [[:b 2] [:a 1]])
+      (let [c []]
+        (assert-eq (into c (b)) [[:b 2]]))
+      (let [c []]
+        (assert-eq (into c (a)) [[:a 1]]))
+      (let [c []]
+        (assert-eq (into (b) c) (b))
+        (assert-eq (into (a) c) (a))))
+
+    (let [a {}
+          b []]
+      (assert-eq (into a [1 2 3]) [1 2 3])
+      (assert-eq (into b [1 2 3]) [1 2 3]))
+    (let [a {}
+          b []]
+      (assert-eq (into b {:a 1}) [[:a 1]]))))
+
+(deftest let-variants
+  (testing when-let
+    (assert-eq (when-let [a 4] a) 4)
+    (assert* (not (when-let [a false] a)) "(not (when-let [a false] a))")
+    (assert* (not (when-let [a nil] a)) "(not (when-let [a nil] a))"))
+
+  (testing when-some
+    (assert-eq (when-some [a [1 2 3]] a) [1 2 3])
+    (assert-eq (when-some [a false] a) false)
+    (assert* (not (when-some [a nil] a)) "(when-some [a nil] a)"))
+
+  (testing if-let
+    (assert-eq (if-let [a 4] a 10) 4)
+    (assert-eq (if-let [a false] a 10) 10)
+    (assert-eq (if-let [a nil] a 10) 10))
+
+  (testing if-some
+    (assert-eq (if-some [a [1 2 3]] a :nothing) [1 2 3])
+    (assert-eq (if-some [a false] a :nothing) false)
+    (assert-eq (if-some [a nil] a :nothing) :nothing)))
+
+(deftest multimethods
+  (testing defmulti
+    (defmulti x (fn [x] x))
+    (assert-eq (defmulti x (fn [x] (+ x 1))) nil))
+
+  (testing defmethod
+    (defmulti fac identity)
+    (defmethod fac 0 [_] 1)
+    (defmethod fac :default [x] (* x (fac (- x 1))))
+    (assert-eq (fac 42) 7538058755741581312)
+
+    (defmulti send-data (fn [protocol data] protocol))
+    (defmethod send-data :http [protocol data] (.. data " will be sent over HTTP"))
+    (defmethod send-data :icap [protocol data] (.. data " will be sent over ICAP"))
+    (assert-eq (send-data :http 42) "42 will be sent over HTTP")
+    (assert-eq (send-data :icap 42) "42 will be sent over ICAP")
+
+    (defmulti send-message (fn [message] (. message :protocol)))
+    (defmethod send-message :http [message] (.. "sending " (. message :message) " over HTTP"))
+    (defmethod send-message :icap [message] (.. "sending " (. message :message) " over ICAP"))
+    (assert-eq (send-message {:protocol :http :message "ваыв"})
+               "sending ваыв over HTTP")
+    (assert-eq (send-message {:protocol :icap :message 42})
+               "sending 42 over ICAP")))
+
+(deftest def-macros
+  (testing def
+    (def {:dynamic true} a 10)
+    (assert-eq a 10)
+    (set a 20)
+    (assert-eq a 20)
+    (def a {})
+    (assert-eq a {})
+    (def a.b 10)
+    (assert-eq a.b 10)
+    (assert-eq b 10)
+    (def :dynamic c 10)
+    (set c 15)
+    (assert-eq c 15))
+
+  (testing defonce
+    (defonce {:dynamic true} a 10)
+    (assert-eq a 10)
+    (defonce a {})
+    (assert-eq a 10)
+    (defonce b {})
+    (defonce b.a 10)
+    (assert-eq b.a 10)
+    (assert-eq a 10)))
+
+(deftest meta
+  (testing with-meta
+    (assert-eq (meta (with-meta :a {:k :v})) {:k :v}))
+
+  (testing def-meta
+    (def {:doc "x"} x 10)
+    (assert-eq (meta x) {:fnl/docstring "x"})
+    (def {:doc "x" :dynamic true} x 10)
+    (assert-eq (meta x) {:fnl/docstring "x"}))
+
+  (testing defonce-meta
+    (defonce {:doc "x"} x 10)
+    (assert-eq (meta x) {:fnl/docstring "x"})
+    (defonce {:doc "y"} x 20)
+    (assert-eq (meta x) {:fnl/docstring "x"})
+    (defonce {:doc "y" :dynamic true} y 20)
+    (assert-eq (meta y) {:fnl/docstring "y"})))
diff --git a/test/test.fnl b/test/test.fnl
new file mode 100644
index 0000000..4b40832
--- /dev/null
+++ b/test/test.fnl
@@ -0,0 +1,51 @@
+(import-macros {: fn*} :macros.fn)
+;; requires `eq' from core.fnl to be available at runtime
+
+(fn* assert-eq
+  ([expr1 expr2]
+   (assert-eq expr1 expr2 nil))
+  ([expr1 expr2 msg]
+   `(let [left# ,expr1
+          right# ,expr2
+          (res# view#) (pcall require :fennelview)]
+      (assert (eq left# right#) (or ,msg (.. "equality assertion failed
+  Left: " ((if res# view# tostring) left#) "
+  Right: " ((if res# view# tostring) right#) "\n"))))))
+
+(fn* assert-ne
+  ([expr1 expr2]
+   (assert-ne expr1 expr2 nil))
+  ([expr1 expr2 msg]
+   `(let [left# ,expr1
+          right# ,expr2
+          (res# view#) (pcall require :fennelview)]
+      (assert (not (eq left# right#)) (or ,msg (.. "unequality assertion failed
+  Left: " ((if res# view# tostring) left#) "
+  Right: " ((if res# view# tostring) right#) "\n"))))))
+
+(fn* assert*
+  ([expr]
+   (assert* expr nil))
+  ([expr msg]
+   `(assert ,expr (.. "assertion failed for " (or ,msg ,(tostring expr))))))
+
+(fn* deftest [name docstring & tests]
+  "Simple way of grouping tests"
+  `(do
+     ,docstring
+     ,((or table.unpack _G.unpack) tests)))
+
+(fn* testing
+  "Define test function, print its name and run it."
+  [name & body]
+  (let [test-name (sym (.. (tostring name) "-test"))]
+    `(do (fn ,test-name []
+           ,((or table.unpack _G.unpack) body))
+         (io.stderr:write (.. "running: " ,(tostring test-name) "\n"))
+         (,test-name))))
+
+{: assert-eq
+ : assert-ne
+ : assert*
+ : deftest
+ : testing}