add tests

go.mod

@@ -1,3 +1,5 @@
 module github.com/vivek-ng/rate-limiter
 
 go 1.14
+
+require github.com/stretchr/testify v1.6.1

go.sum

@@ -0,0 +1,10 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

rateLimiter_test.go

@@ -0,0 +1,47 @@
+package limiter
+
+import (
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestConcurrentRateLimiterNonBlocking(t *testing.T) {
+	l := NewLimiter(7)
+
+	var wg sync.WaitGroup
+	wg.Add(5)
+
+	for i := 0; i < 5; i++ {
+		go func() {
+			defer wg.Done()
+			l.Wait()
+		}()
+	}
+
+	wg.Wait()
+	assert.Equal(t, 0, l.waitList.Len())
+}
+
+func TestConcurrentRateLimiterBlocking(t *testing.T) {
+	l := NewLimiter(2)
+
+	var wg sync.WaitGroup
+	wg.Add(5)
+
+	for i := 0; i < 5; i++ {
+		go func() {
+			defer wg.Done()
+			l.Wait()
+		}()
+	}
+	time.Sleep(100 * time.Millisecond)
+	assert.Equal(t, 3, l.waitList.Len())
+	l.Finish()
+	l.Finish()
+	l.Finish()
+	wg.Wait()
+	assert.Equal(t, 0, l.waitList.Len())
+}