bumping test coverage, adding more tests.

Signed-off-by: Dave Shanley <dave@quobix.com>

datamodel/low/extraction_functions_test.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/pb33f/libopenapi/index"
@@ -1615,11 +1616,19 @@ x-tacos: [1,2,3]`
 }
 
 type test_fresh struct {
-	val string
+	val   string
+	thang *bool
 }
 
 func (f test_fresh) Hash() [32]byte {
-	return sha256.Sum256([]byte(f.val))
+	var data []string
+	if f.val != "" {
+		data = append(data, f.val)
+	}
+	if f.thang != nil {
+		data = append(data, fmt.Sprintf("%v", *f.thang))
+	}
+	return sha256.Sum256([]byte(strings.Join(data, "|")))
 }
 func TestAreEqual(t *testing.T) {
 	assert.True(t, AreEqual(test_fresh{val: "hello"}, test_fresh{val: "hello"}))
@@ -1637,6 +1646,17 @@ func TestGenerateHashString(t *testing.T) {
 
 }
 
+func TestGenerateHashString_Pointer(t *testing.T) {
+
+	val := true
+	assert.Equal(t, "b5bea41b6c623f7c09f1bf24dcae58ebab3c0cdd90ad966bc43a45b44867e12b",
+		GenerateHashString(test_fresh{thang: &val}))
+
+	assert.Equal(t, "b5bea41b6c623f7c09f1bf24dcae58ebab3c0cdd90ad966bc43a45b44867e12b",
+		GenerateHashString(&val))
+
+}
+
 func TestSetReference(t *testing.T) {
 
 	type testObj struct {