test(Pair): add tests for Pair

safareli · Oct 11, 2016 · c776ace · c776ace
1 parent a451348
commit c776ace
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Showing 3 changed files with 46 additions and 3 deletions.
diff --git a/examples/Pair.js b/examples/Pair.js
@@ -16,11 +16,16 @@ Pair.prototype.equals = function(b) {
 
 // instance (Semigroup a, Semigroup b) => Semigroup (Pair a b) where
 //   concat :: Pair a b ~> Pair a b -> Pair a b
-Pair.prototype.concat = function(b) {
+Pair.prototype.concat = function(x) {
+  const b = Q.foldIfIsOf(Pair[fl.of], x)
   if (Q.isEmpty(this._1) || Q.isEmpty(this._2)) {
-    return b
-  } else if (Q.isEmpty(b) || Q.isEmpty(b._1) || Q.isEmpty(b._2)) {
+    return Pair(this._1[fl.concat](b._1), this._2[fl.concat](b._2))
+  } else if (Q.isEmpty(b) || (Q.isEmpty(b._1) && Q.isEmpty(b._2))) {
     return this
+  } else if (Q.isEmpty(b._1)) {
+    return Pair(this._1, this._2[fl.concat](b._2))
+  } else if (Q.isEmpty(b._2)) {
+    return Pair(this._1[fl.concat](b._1), this._2)
   } else {
     return Pair(this._1[fl.concat](b._1), this._2[fl.concat](b._2))
   }
@@ -48,6 +53,10 @@ Pair.prototype.ap = function(f) {
 //   of :: a -> Pair a
 Pair.of = (a) => Pair(Q.empty, a)
 
+Pair.prototype.toString = function() {
+  return 'Pair(' + this._1 + ',' + this._2 + ')'
+}
+
 flPatch([Pair, Pair.prototype])
 
 module.exports = Pair
diff --git a/test/List.js b/test/List.js
@@ -7,9 +7,11 @@ const List = require('../examples/List.js')
 test('eq', t => {
   const a = 'a'
   const as = List.fromArray([a])
+  const a2s = List.fromArray([a, a])
 
   t.equals('Cons(a,Nil)', as.toString())
   t.eqFL(as, as.concat(empty))
+  t.eqFL(a2s, as.concat(as))
   t.notOk(List.fromArray([a, a]).equals(List.fromArray([a])))
   t.notOk(List.fromArray([a]).equals(List.fromArray([a, a])))
   t.eqFL(of(as), of(a).reduce((acc, a) => List.Cons(a, acc), List.Nil))

diff --git a/test/Pair.js b/test/Pair.js
@@ -0,0 +1,32 @@
+const { test } = require('./lib')
+
+const { of, empty } = require('../src/quasi.js')
+
+const Pair = require('../examples/Pair.js')
+const List = require('../examples/List.js')
+
+test('eq', t => {
+  const a = 'a'
+  const as = List.fromArray([a])
+  const a2s = List.fromArray([a, a])
+  t.equals('Pair(a,a)', Pair(a, a).toString())
+  t.eqFL(Pair(as, as), Pair(empty, empty).concat(Pair(as, as)))
+  t.eqFL(Pair(as, as), Pair(as, as).concat(Pair(empty, empty)))
+  t.eqFL(Pair(a2s, as), Pair(as, empty).concat(Pair(as, as)))
+  t.eqFL(Pair(as, a2s), Pair(empty, as).concat(Pair(as, as)))
+  t.eqFL(Pair(as, as), Pair(as, as).concat(empty))
+  t.eqFL(Pair(as, as), empty.concat(Pair(as, as)))
+  t.eqFL(Pair(a2s, as), Pair(as, as).concat(Pair(as, empty)))
+  t.eqFL(Pair(as, a2s), Pair(as, as).concat(Pair(empty, as)))
+  t.eqFL(Pair(as, a2s), Pair(as, as).concat(of(as)))
+  t.eqFL(Pair(as, as), Pair(as, as).concat(Pair(empty, empty)))
+  t.eqFL(Pair(a2s, a2s), Pair(as, as).concat(Pair(as, as)))
+  t.eqFL(Pair(a2s, as), Pair(as, as).concat(Pair(as, empty)))
+  t.eqFL(Pair(as, a2s), Pair(as, as).concat(of(as)))
+  t.eqFL(Pair(as, a2s), of(as).concat(Pair(as, as)))
+  t.eqFL(Pair(as, as), Pair(as, as).ap(Pair.of(as => as)))
+  t.eqFL(Pair(as, as), Pair(as, as).ap(of(as => as)))
+  t.eqFL(Pair(a2s, as), Pair(as, as).ap(Pair(as, as => as)))
+  t.eqFL(Pair(as, a2s), Pair(as, as).map((as) => as.concat(as)))
+  t.end()
+})