add missing tests

cache_test.go

@@ -1,6 +1,7 @@
 package lcw
 
 import (
+	"errors"
 	"fmt"
 	"math/rand"
 	"strings"
@@ -33,6 +34,20 @@ func TestCache_Get(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, "result", res.(string))
 	assert.Equal(t, int32(1), atomic.LoadInt32(&coldCalls), "cache hit")
+
+	_, err = lc.Get("key-2", func() (Value, error) {
+		atomic.AddInt32(&coldCalls, 1)
+		return "result2", errors.New("some error")
+	})
+	assert.NotNil(t, err)
+	assert.Equal(t, int32(2), atomic.LoadInt32(&coldCalls), "cache hit")
+
+	_, err = lc.Get("key-2", func() (Value, error) {
+		atomic.AddInt32(&coldCalls, 1)
+		return "result2", errors.New("some error")
+	})
+	assert.NotNil(t, err)
+	assert.Equal(t, int32(3), atomic.LoadInt32(&coldCalls), "cache hit")
 }
 
 func TestCache_Peek(t *testing.T) {
@@ -200,6 +215,34 @@ func TestCache_MaxCacheSizeParallel(t *testing.T) {
 	t.Log("size", lc.currentSize)
 }
 
+func TestCache_MaxKeySize(t *testing.T) {
+	lc, err := NewCache(MaxKeySize(5))
+	require.Nil(t, err)
+
+	res, err := lc.Get("key", func() (Value, error) {
+		return "value", nil
+	})
+	assert.Nil(t, err)
+	assert.Equal(t, "value", res.(string))
+
+	res, err = lc.Get("key", func() (Value, error) {
+		return "valueXXX", nil
+	})
+	assert.Nil(t, err)
+	assert.Equal(t, "value", res.(string), "cached")
+
+	res, err = lc.Get("key1234", func() (Value, error) {
+		return "value", nil
+	})
+	assert.Nil(t, err)
+	assert.Equal(t, "value", res.(string))
+
+	res, err = lc.Get("key1234", func() (Value, error) {
+		return "valueXYZ", nil
+	})
+	assert.Nil(t, err)
+	assert.Equal(t, "valueXYZ", res.(string), "not cached")
+}
 func TestCache_Parallel(t *testing.T) {
 	var coldCalls int32
 	lc, err := NewCache()
@@ -265,6 +308,25 @@ func TestCache_Invalidate(t *testing.T) {
 	assert.Equal(t, "result-xxx", res.(string), "not from the cache")
 }
 
+func TestCache_Purge(t *testing.T) {
+	var coldCalls int32
+	lc, err := NewCache()
+	require.Nil(t, err)
+
+	// fill cache
+	for i := 0; i < 1000; i++ {
+		_, err := lc.Get(fmt.Sprintf("key-%d", i), func() (Value, error) {
+			atomic.AddInt32(&coldCalls, 1)
+			return fmt.Sprintf("result-%d", i), nil
+		})
+		require.Nil(t, err)
+	}
+	assert.Equal(t, int32(1000), atomic.LoadInt32(&coldCalls))
+	assert.Equal(t, 1000, lc.backend.Len())
+
+	lc.Purge()
+	assert.Equal(t, 0, lc.backend.Len(), "all keys removed")
+}
 func TestCache_BadOptions(t *testing.T) {
 	_, err := NewCache(MaxCacheSize(-1))
 	assert.EqualError(t, err, "failed to set cache option: negative max cache size")

go.mod

@@ -3,4 +3,5 @@ module github.com/go-pkgz/lcw
 require (
 	github.com/hashicorp/golang-lru v0.5.0
 	github.com/pkg/errors v0.8.1
+	github.com/stretchr/testify v1.3.0
 )

go.sum

@@ -1,4 +1,11 @@
+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/hashicorp/golang-lru v0.5.0 h1:CL2msUPvZTLb5O648aiLNJw3hnBxN2+1Jq8rCOH9wdo=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+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 v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=