add some ifvalue tests and error checks

Signed-off-by: Doug Davis <[email protected]>

README.md

@@ -140,7 +140,6 @@ TODOs:
 - multi-delete must ignore all attributes except id and epoch
 - fix init.sql, it's too slow due to latest xref stuff in commit 9c583e7
 - add support for inline=endpoints.*
-- ban the use of ^ in ifvalue VALUES for now
 - support ETag/If-Match
 - update epoch/modifiedat of parent when nested entity is added/removed
 - ?nested isn't needed to update `model` or `meta` attributes

registry/model.go

@@ -2390,6 +2390,11 @@ func (attrs Attributes) Verify(ld *LevelData) error {
 				return fmt.Errorf("%q has an empty ifvalues key", ld.Path.UI())
 			}
 
+			if valStr[0] == '^' {
+				return fmt.Errorf("%q has an ifvalues key that starts "+
+					"with \"^\"", ld.Path.UI())
+			}
+
 			nextLD := &LevelData{
 				ld.Model,
 				ld.AttrNames,

tests/http1_test.go

@@ -4919,6 +4919,24 @@ func TestHTTPIfValue(t *testing.T) {
 	})
 	xCheckErr(t, err, "")
 
+	_, err = reg.Model.AddAttribute(&registry.Attribute{
+		Name: "badone",
+		Type: registry.INTEGER,
+		IfValues: registry.IfValues{
+			"": &registry.IfValue{},
+		},
+	})
+	xCheckErr(t, err, "\"model\" has an empty ifvalues key")
+
+	_, err = reg.Model.AddAttribute(&registry.Attribute{
+		Name: "badone",
+		Type: registry.INTEGER,
+		IfValues: registry.IfValues{
+			"^6": &registry.IfValue{},
+		},
+	})
+	xCheckErr(t, err, "\"model\" has an ifvalues key that starts with \"^\"")
+
 	xCheckHTTP(t, reg, &HTTPTest{
 		Name:   "PUT reg - ifvalue - 1",
 		URL:    "",