Contract 'he is not' to he's not instead of he'sn't

src/2-two/contraction-two/api/contract.js

@@ -45,8 +45,8 @@ const contract = function () {
   // spencer would -> spencer'd
   m = doc.match('#Person would')
   setContraction(m, `'d`)
-  // would not -> wouldn't
-  m = doc.match('(is|was|had|would|should|could|do|does|have|has|can) not')
+  // would not -> wouldn't (skip words already contracted above, like he's)
+  m = doc.match('(is|was|had|would|should|could|do|does|have|has|can) not').ifNo('@hasContraction')
   setContraction(m, `n't`)
   // i have -> i've
   m = doc.match('(i|we|they) have')

tests/two/contractions/contract.test.js

@@ -41,6 +41,23 @@ test('contract basic', function (t) {
   t.end()
 })
 
+test('contract before not', function (t) {
+  let doc = nlp('he is not here')
+  doc.contract()
+  t.equal(doc.text(), `he's not here`, here + 'he is not')
+  doc.contractions().expand()
+  t.equal(doc.text(), 'he is not here', here + 'he is not expand')
+
+  doc = nlp('spencer is not here')
+  doc.contract()
+  t.equal(doc.text(), `spencer's not here`, here + 'spencer is not')
+
+  doc = nlp('that is not true')
+  doc.contract()
+  t.equal(doc.text(), `that isn't true`, here + 'that is not')
+  t.end()
+})
+
 test('avoid contraction messes', function (t) {
   let doc = nlp('Tony, is').contract()
   t.equal(doc.has('is'), true, here + 'avoid-contraction 1')