Add validation for empty predicate

Empty predicate won't be defaulted to "MENTIONS" predicate anymore.
The commit also updates the unit tests to match the new behavior.

annotations/cypher.go

@@ -191,10 +191,6 @@ func createAnnotationRelationship(relation string) (statement string) {
 }
 
 func getRelationshipFromPredicate(predicate string) (string, error) {
-	if predicate == "" {
-		return relations["mentions"], nil
-	}
-
 	r, ok := relations[predicate]
 	if !ok {
 		return "", UnsupportedPredicateErr

annotations/cypher_integration_test.go

@@ -372,6 +372,7 @@ func TestWriteAndReadMultipleAnnotations(t *testing.T) {
 					"http://www.ft.com/ontology/core/Thing",
 					"http://www.ft.com/ontology/concept/Concept",
 				},
+				Predicate: "mentions",
 			},
 			Provenances: []Provenance{
 				{

annotations/cypher_test.go

@@ -1,6 +1,7 @@
 package annotations
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 
@@ -99,16 +100,30 @@ func TestCreateAnnotationQueryWithPredicate(t *testing.T) {
 	}
 }
 
+func TestCreateAnnotationQueryWithoutPredicate(t *testing.T) {
+	assert := assert.New(t)
+	logger.InitDefaultLogger("annotations-rw")
+	annotation := exampleConcept(oldConceptUUID)
+	annotation.Thing.Predicate = ""
+
+	_, err := createAnnotationQuery(contentUUID, annotation, v2PlatformVersion, v2AnnotationLifecycle)
+	assert.True(errors.Is(err, UnsupportedPredicateErr), "Creating annotation without predicate is not allowed.")
+}
+
 func TestGetRelationshipFromPredicate(t *testing.T) {
 	var tests = []struct {
 		predicate    string
 		relationship string
 	}{
 		{"mentions", "MENTIONS"},
 		{"isClassifiedBy", "IS_CLASSIFIED_BY"},
-		{"", "MENTIONS"},
+		{"implicitlyClassifiedBy", "IMPLICITLY_CLASSIFIED_BY"},
 		{"about", "ABOUT"},
+		{"isPrimarilyClassifiedBy", "IS_PRIMARILY_CLASSIFIED_BY"},
+		{"majorMentions", "MAJOR_MENTIONS"},
 		{"hasAuthor", "HAS_AUTHOR"},
+		{"hasContributor", "HAS_CONTRIBUTOR"},
+		{"hasDisplayTag", "HAS_DISPLAY_TAG"},
 		{"hasBrand", "HAS_BRAND"},
 	}
 

annotations/example_data_test.go

@@ -20,7 +20,9 @@ var (
 				"http://www.ft.com/ontology/organisation/Organisation",
 				"http://www.ft.com/ontology/core/Thing",
 				"http://www.ft.com/ontology/concept/Concept",
-			}},
+			},
+			Predicate: "mentions",
+		},
 		Provenances: []Provenance{
 			{
 				Scores: []Score{
@@ -192,7 +194,9 @@ func exampleConcept(uuid string) Annotation {
 				"http://www.ft.com/ontology/organisation/Organisation",
 				"http://www.ft.com/ontology/core/Thing",
 				"http://www.ft.com/ontology/concept/Concept",
-			}},
+			},
+			Predicate: "mentions",
+		},
 		Provenances: []Provenance{
 			{
 				Scores: []Score{