Fixed panic on resize. Added NewClassWIndex funciton

Author: kucjac

class.go

@@ -85,6 +85,20 @@ func NewClass(mjr Major, mnr Minor, index Index) (Class, error) {
 	return newClass(mjr, mnr, index)
 }
 
+// NewClassWIndex creates new index and class for provided 'mjr' Major and 'mnr' Minor.
+// Returns error if any of the input values are not valid.
+func NewClassWIndex(mjr Major, mnr Minor) (Class, error) {
+	return newClassWIndex(mjr, mnr)
+}
+
+func newClassWIndex(mjr Major, mnr Minor) (Class, error) {
+	index, err := container.newIndex(mjr, mnr)
+	if err != nil {
+		return 0, err
+	}
+	return newClass(mjr, mnr, index)
+}
+
 // MustNewClass gets new class from the provided 'minor' and 'index'.
 // Panics if any of the arguments is not valid or out of bands.
 func MustNewClass(mjr Major, mnr Minor, index Index) Class {
@@ -95,6 +109,17 @@ func MustNewClass(mjr Major, mnr Minor, index Index) Class {
 	return c
 }
 
+// MustNewClassWIndex creates new 'mjr' Major, 'mnr' Minor 'index' and then
+// a new Class for provided triplet.
+// Panics on error.
+func MustNewClassWIndex(mjr Major, mnr Minor) Class {
+	c, err := newClassWIndex(mjr, mnr)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
 // NewMinorClass gets the class from provided 'minor'.
 // The function gets minor's major and gets the major/minor class.
 func NewMinorClass(mjr Major, mnr Minor) (Class, error) {

class_test.go

@@ -91,6 +91,7 @@ func TestClass(t *testing.T) {
 		}
 
 		assert.NotEqual(t, initLen, len(container.indexes[mjr]))
+
 	})
 
 	t.Run("Index", func(t *testing.T) {
@@ -152,6 +153,22 @@ func TestClass(t *testing.T) {
 		assert.Panics(t, func() { MustNewClass(mjr, invMnr, inx2) })
 		assert.Panics(t, func() { MustNewClass(invMjr, mnr, inx2) })
 		assert.Panics(t, func() { MustNewClass(mjr, mnr, invIndex) })
+
+		c, err := NewClassWIndex(mjr, mnr)
+		require.NoError(t, err)
+
+		var c2 Class
+
+		assert.NotPanics(t, func() { c2 = MustNewClassWIndex(mjr, mnr) })
+		assert.NotEqual(t, c, c2)
+
+		_, err = NewClassWIndex(invMjr, mnr)
+		assert.Error(t, err)
+
+		_, err = NewClassWIndex(mjr, invMnr)
+		assert.Error(t, err)
+
+		assert.Panics(t, func() { MustNewClassWIndex(invMjr, mnr) })
 	})
 }
 

container.go

@@ -27,6 +27,9 @@ func (c *classContainer) newMajor() Major {
 }
 
 func (c *classContainer) newMinor(mjr Major) (Minor, error) {
+	c.Lock()
+	defer c.Unlock()
+
 	if !mjr.Valid() {
 		return 0, New(ClInvalidMajor, "provided invalid Major")
 	}
@@ -39,6 +42,9 @@ func (c *classContainer) newMinor(mjr Major) (Minor, error) {
 }
 
 func (c *classContainer) newIndex(mjr Major, mnr Minor) (Index, error) {
+	c.Lock()
+	defer c.Unlock()
+
 	if !mjr.Valid() {
 		return 0, New(ClInvalidMajor, "provided invalid Major")
 	}
@@ -64,9 +70,10 @@ func (c *classContainer) resizeMinors(mjr Major) {
 		size = 4
 	}
 
-	for size < int(mjr) {
+	for size <= int(mjr) {
 		size *= 2
 	}
+
 	temp := make([]Minor, size)
 	copy(temp, c.minors)
 	c.minors = temp
@@ -82,7 +89,7 @@ func (c *classContainer) resizeIndexesMajor(mjr Major) {
 		size = 4
 	}
 
-	for size < int(mjr) {
+	for size <= int(mjr) {
 		size *= 2
 	}
 	temp := make([][]Index, size)
@@ -100,7 +107,7 @@ func (c *classContainer) resizeIndexesMinors(mjr Major, mnr Minor) {
 		size = 4
 	}
 
-	for size < int(mnr) {
+	for size <= int(mnr) {
 		size *= 2
 	}
 	temp := make([]Index, size)