Addressing comments + fixing copypasta

rules/mapping.go

@@ -32,9 +32,9 @@ import (
 )
 
 var (
-	errBadMappingRuleSnapshotIdx    = errors.New("mapping rule snapshot index out of range")
-	errNilMappingRuleSnapshotSchema = errors.New("nil mapping rule snapshot schema")
-	errNilMappingRuleSchema         = errors.New("nil mapping rule schema")
+	errMappingRuleSnapshotIdxOutOfRange = errors.New("mapping rule snapshot index out of range")
+	errNilMappingRuleSnapshotSchema     = errors.New("nil mapping rule snapshot schema")
+	errNilMappingRuleSchema             = errors.New("nil mapping rule schema")
 )
 
 // mappingRuleSnapshot defines a rule snapshot such that if a metric matches the
@@ -146,8 +146,8 @@ type MappingRuleView struct {
 }
 
 func (mc *mappingRule) mappingRuleView(snapshotIdx int) (*MappingRuleView, error) {
-	if snapshotIdx < 0 || snapshotIdx > len(mc.snapshots) {
-		return nil, errBadMappingRuleSnapshotIdx
+	if snapshotIdx < 0 || snapshotIdx >= len(mc.snapshots) {
+		return nil, errMappingRuleSnapshotIdxOutOfRange
 	}
 
 	mrs := mc.snapshots[snapshotIdx].clone()

rules/mapping_test.go

@@ -308,9 +308,12 @@ func TestNewMappingRuleViewError(t *testing.T) {
 	mr, err := newMappingRule(testMappingRuleSchema, testTagsFilterOptions())
 	require.NoError(t, err)
 
-	actual, err := mr.mappingRuleView(20)
-	require.Error(t, err)
-	require.Nil(t, actual)
+	badIdx := []int{-2, 2, 30}
+	for _, i := range badIdx {
+		actual, err := mr.mappingRuleView(i)
+		require.Error(t, err)
+		require.Nil(t, actual)
+	}
 }
 
 func TestMappingRuleHistory(t *testing.T) {

rules/namespace.go

@@ -32,16 +32,16 @@ var (
 	emptyNamespace         Namespace
 	emptyNamespaces        Namespaces
 
-	errBadNamespaceSnapshotIdx    = errors.New("namespace snapshot idx out of range")
-	errNilNamespaceSnapshotSchema = errors.New("nil namespace snapshot schema")
-	errNilNamespaceSchema         = errors.New("nil namespace schema")
-	errNilNamespacesSchema        = errors.New("nil namespaces schema")
-	errNilNamespaceSnapshot       = errors.New("nil namespace snapshot")
-	errMultipleNamespaceMatches   = errors.New("more than one namespace match found")
-	errNamespaceNotFound          = errors.New("namespace not found")
-	errNamespaceNotTombstoned     = errors.New("not tombstoned")
-	errNamespaceTombstoned        = errors.New("already tombstoned")
-	errNoNamespaceSnapshots       = errors.New("no snapshots")
+	errNamespaceSnapshotIdxOutOfRange = errors.New("namespace snapshot idx out of range")
+	errNilNamespaceSnapshotSchema     = errors.New("nil namespace snapshot schema")
+	errNilNamespaceSchema             = errors.New("nil namespace schema")
+	errNilNamespacesSchema            = errors.New("nil namespaces schema")
+	errNilNamespaceSnapshot           = errors.New("nil namespace snapshot")
+	errMultipleNamespaceMatches       = errors.New("more than one namespace match found")
+	errNamespaceNotFound              = errors.New("namespace not found")
+	errNamespaceNotTombstoned         = errors.New("not tombstoned")
+	errNamespaceTombstoned            = errors.New("already tombstoned")
+	errNoNamespaceSnapshots           = errors.New("no snapshots")
 
 	namespaceActionErrorFmt = "cannot %s namespace %s. %v"
 )
@@ -109,8 +109,8 @@ type NamespaceView struct {
 }
 
 func (n Namespace) namespaceView(snapshotIdx int) (*NamespaceView, error) {
-	if snapshotIdx < 0 || snapshotIdx > len(n.snapshots) {
-		return nil, errBadNamespaceSnapshotIdx
+	if snapshotIdx < 0 || snapshotIdx >= len(n.snapshots) {
+		return nil, errNamespaceSnapshotIdxOutOfRange
 	}
 	s := n.snapshots[snapshotIdx]
 	return &NamespaceView{

rules/namespace_test.go

@@ -587,7 +587,7 @@ func TestNamespaceViewError(t *testing.T) {
 		},
 	}
 
-	badIdx := []int{30, -2}
+	badIdx := []int{-2, 2, 30}
 	for _, i := range badIdx {
 		actual, err := n.namespaceView(i)
 		require.Error(t, err)

rules/rollup.go

@@ -36,10 +36,10 @@ import (
 var (
 	emptyRollupTarget RollupTarget
 
-	errBadRollupRuleSnapshotIdx    = errors.New("rollup rule snapshot index out of range")
-	errNilRollupTargetSchema       = errors.New("nil rollup target schema")
-	errNilRollupRuleSnapshotSchema = errors.New("nil rollup rule snapshot schema")
-	errNilRollupRuleSchema         = errors.New("nil rollup rule schema")
+	errRollupRuleSnapshotIdxOutOfRange = errors.New("rollup rule snapshot index out of range")
+	errNilRollupTargetSchema           = errors.New("nil rollup target schema")
+	errNilRollupRuleSnapshotSchema     = errors.New("nil rollup rule snapshot schema")
+	errNilRollupRuleSchema             = errors.New("nil rollup rule schema")
 )
 
 // RollupTarget dictates how to roll up metrics. Metrics associated with a rollup
@@ -268,8 +268,8 @@ type RollupRuleView struct {
 }
 
 func (rc *rollupRule) rollupRuleView(snapshotIdx int) (*RollupRuleView, error) {
-	if snapshotIdx < 0 || snapshotIdx > len(rc.snapshots) {
-		return nil, errBadRollupRuleSnapshotIdx
+	if snapshotIdx < 0 || snapshotIdx >= len(rc.snapshots) {
+		return nil, errRollupRuleSnapshotIdxOutOfRange
 	}
 
 	rrs := rc.snapshots[snapshotIdx].clone()

rules/rollup_test.go

@@ -405,9 +405,12 @@ func TestNewRollupRuleView(t *testing.T) {
 func TestNewRollupRuleViewError(t *testing.T) {
 	rr, err := newRollupRule(testRollupRuleSchema, testTagsFilterOptions())
 	require.NoError(t, err)
-	actual, err := rr.rollupRuleView(20)
-	require.Error(t, err)
-	require.Nil(t, actual)
+	badIdx := []int{-2, 2, 30}
+	for _, i := range badIdx {
+		actual, err := rr.rollupRuleView(i)
+		require.Error(t, err)
+		require.Nil(t, actual)
+	}
 }
 
 func TestNewRollupRuleHistory(t *testing.T) {