Added err detection for io.EOF and more sample for save/load RuleSet …

…binary (#185)

ast/KnowledgeBase.go

@@ -70,7 +70,7 @@ func (lib *KnowledgeLibrary) LoadKnowledgeBaseFromReader(reader io.Reader, overw
 
 	catalog := &Catalog{}
 	err := catalog.ReadCatalogFromReader(reader)
-	if err != nil {
+	if err != nil && err != io.EOF {
 		return nil, err
 	}
 	kb := catalog.BuildKnowledgeBase()

examples/Serialization_test.go

@@ -20,6 +20,8 @@ import (
 	"github.com/hyperjumptech/grule-rule-engine/builder"
 	"github.com/hyperjumptech/grule-rule-engine/pkg"
 	"github.com/stretchr/testify/assert"
+	"io"
+	"os"
 	"testing"
 )
 
@@ -39,8 +41,50 @@ func TestSerialization(t *testing.T) {
 	buff2 := bytes.NewBuffer(buff1.Bytes())
 	cat2 := &ast.Catalog{}
 	err = cat2.ReadCatalogFromReader(buff2)
-	assert.Nil(t, err)
+	if err != nil && err != io.EOF {
+		assert.Nil(t, err)
+	}
 
 	kb2 := cat2.BuildKnowledgeBase()
 	assert.True(t, kb.IsIdentical(kb2))
 }
+
+func TestSerializationOnFile(t *testing.T) {
+	testFile := "Test.GRB"
+
+	// SAFING INTO FILE
+	// First prepare our library for loading the orignal GRL
+	lib := ast.NewKnowledgeLibrary()
+	rb := builder.NewRuleBuilder(lib)
+	err := rb.BuildRuleFromResource("Purchase Calculator", "0.0.1", pkg.NewFileResource("CashFlowRule.grl"))
+	assert.NoError(t, err)
+
+	// Lets create the file to write into
+	f, err := os.OpenFile(testFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	assert.Nil(t, err)
+
+	// Save the knowledge base into the file and close it.
+	err = lib.StoreKnowledgeBaseToWriter(f, "load_rules_test", "0.1.1")
+	assert.Nil(t, err)
+	_ = f.Close()
+
+	// LOADING FROM FILE
+	// Lets assume we are using different library, so create a new one
+	lib2 := ast.NewKnowledgeLibrary()
+
+	// Open the existing safe file
+	f2, err := os.Open(testFile)
+	assert.Nil(t, err)
+
+	// Load the file directly into the library and close the file
+	kb2, err := lib2.LoadKnowledgeBaseFromReader(f2, true)
+	assert.Nil(t, err)
+	_ = f2.Close()
+
+	// Delete the test file
+	err = os.Remove(testFile)
+	assert.Nil(t, err)
+
+	// compare that the original knowledgebase is exacly the same to the loaded one.
+	assert.True(t, lib.GetKnowledgeBase("load_rules_test", "0.1.1").IsIdentical(kb2))
+}