4 files changed, 141 insertions, 32 deletions
diff --git a/internal/feed/feed.go b/internal/feed/feed.go
index 98e62ef..b9f7678 100644
--- a/internal/feed/feed.go
+++ b/internal/feed/feed.go
@@ -11,11 +11,6 @@ const (
   Medium          // medium complexity/priv req
   High            // high complexity/priv req
 
-  Required        // user interaction required
-
-  Changed         // scope changed
-  Unchanged       // scope unchanged
-
   Complete        // complete integrity impact
   Partial         // partial integrity impact
 
@@ -29,32 +24,6 @@ const (
 
 // TODO: parse cpe
 
-// CVSS scope
-type Scope int
-
-// Unmarshal CVSS scope from JSON.
-func (me *Scope) UnmarshalJSON(b []byte) error {
-  // decode string, check for error
-  var s string
-  if err := json.Unmarshal(b, &s); err != nil {
-    return err
-  }
-
-  // check value
-  switch s {
-  case "CHANGED":
-    *me = Changed
-  case "UNCHANGED":
-    *me = Unchanged
-  default:
-    // return error
-    return fmt.Errorf("unknown scope: %s", s)
-  }
-
-  // return success
-  return nil
-}
-
 // CVSS integrity/availability impact level
 type ImpactLevel int
 
@@ -409,7 +378,7 @@ type CvssV3 struct {
   UserInteraction V3UserInteraction `json:"userInteraction"`
 
   // scope
-  Scope Scope `json:"scope"`
+  Scope V3Scope `json:"scope"`
 
   // integrity impact
   IntegrityImpact ImpactLevel `json:"integrityImpact"`
diff --git a/internal/feed/v3scope.go b/internal/feed/v3scope.go
new file mode 100644
index 0000000..20fe0a5
--- /dev/null
+++ b/internal/feed/v3scope.go
@@ -0,0 +1,39 @@
+package feed
+
+//go:generate stringer -linecomment -type=V3Scope
+
+import (
+  "encoding/json"
+  "fmt"
+)
+
+// CVSS v3 scope.
+type V3Scope byte
+
+const (
+  V3ScopeChanged V3Scope = iota // CHANGED
+  V3ScopeUnchanged // UNCHANGED
+)
+
+// Unmarshal CVSS scope from JSON.
+func (me *V3Scope) UnmarshalJSON(b []byte) error {
+  // decode string, check for error
+  var s string
+  if err := json.Unmarshal(b, &s); err != nil {
+    return err
+  }
+
+  // check value
+  switch s {
+  case "CHANGED":
+    *me = V3ScopeChanged
+  case "UNCHANGED":
+    *me = V3ScopeUnchanged
+  default:
+    // return error
+    return fmt.Errorf("unknown CVSS v3 scope: %s", s)
+  }
+
+  // return success
+  return nil
+}
diff --git a/internal/feed/v3scope_string.go b/internal/feed/v3scope_string.go
new file mode 100644
index 0000000..982cead
--- /dev/null
+++ b/internal/feed/v3scope_string.go
@@ -0,0 +1,24 @@
+// Code generated by "stringer -linecomment -type=V3Scope"; DO NOT EDIT.
+
+package feed
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[V3ScopeChanged-0]
+	_ = x[V3ScopeUnchanged-1]
+}
+
+const _V3Scope_name = "CHANGEDUNCHANGED"
+
+var _V3Scope_index = [...]uint8{0, 7, 16}
+
+func (i V3Scope) String() string {
+	if i >= V3Scope(len(_V3Scope_index)-1) {
+		return "V3Scope(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _V3Scope_name[_V3Scope_index[i]:_V3Scope_index[i+1]]
+}
diff --git a/internal/feed/v3scope_test.go b/internal/feed/v3scope_test.go
new file mode 100644
index 0000000..54170b0
--- /dev/null
+++ b/internal/feed/v3scope_test.go
@@ -0,0 +1,77 @@
+package feed
+
+import (
+  "encoding/json"
+  "testing"
+)
+
+func TestV3ScopeUnmarshalInvalidData(t *testing.T) {
+  test := []byte(`{}`)
+  var val V3Scope
+
+  if err := json.Unmarshal(test, &val); err == nil {
+    t.Errorf("got \"%s\", exp error", val)
+  }
+}
+
+func TestV3ScopeUnmarshalUnknown(t *testing.T) {
+  test := []byte(`"foo"`)
+  exp := "unknown CVSS v3 scope: foo"
+  var val V3Scope
+
+  err := json.Unmarshal(test, &val)
+  if err == nil {
+    t.Errorf("got \"%s\", exp error", val)
+    return
+  }
+
+  if err.Error() != exp {
+    t.Errorf("got \"%s\", exp \"%s\"", err.Error(), exp)
+  }
+}
+
+func TestV3ScopeUnmarshalValid(t *testing.T) {
+  tests := []struct {
+    val string
+    exp V3Scope
+  } {
+    { "\"CHANGED\"", V3ScopeChanged },
+    { "\"UNCHANGED\"", V3ScopeUnchanged },
+  }
+
+  for _, test := range(tests) {
+    t.Run(test.val, func(t *testing.T) {
+      var got V3Scope
+      if err := json.Unmarshal([]byte(test.val), &got); err != nil {
+        t.Error(err)
+        return
+      }
+
+      if got != test.exp {
+        t.Errorf("got \"%s\", exp \"%s\"", got, test.exp)
+      }
+    })
+  }
+}
+
+func TestV3ScopeString(t *testing.T) {
+  tests := []struct {
+    val V3Scope
+    exp string
+  } {
+    { V3ScopeChanged, "CHANGED" },
+    { V3ScopeUnchanged, "UNCHANGED" },
+
+    { V3Scope(255), "V3Scope(255)" },
+  }
+
+  for _, test := range(tests) {
+    t.Run(test.exp, func(t *testing.T) {
+      got := test.val.String()
+
+      if got != test.exp {
+        t.Errorf("got \"%s\", exp \"%s\"", got, test.exp)
+      }
+    })
+  }
+}