Check if field uniqueness was removed

schema.go

@@ -47,6 +47,7 @@ const (
 	DatasetDifferenceTypeFieldRemoved
 	DatasetDifferenceTypeFieldTypeChanged
 	DatasetDifferenceTypeFieldRequirementRemoved
+	DatasetDifferenceTypeFieldUniquenessRemoved
 )
 
 func (d DatasetDifferenceType) String() string {
@@ -59,6 +60,8 @@ func (d DatasetDifferenceType) String() string {
 		return "field-type-changed"
 	case DatasetDifferenceTypeFieldRequirementRemoved:
 		return "field-requirement-removed"
+	case DatasetDifferenceTypeFieldUniquenessRemoved:
+		return "field-uniqueness-removed"
 	}
 
 	return ""
@@ -106,6 +109,7 @@ func CompareDatasets(old, new Dataset) (result []DatasetDifference) {
 		fieldRemoved,
 		fieldTypeChanged,
 		fieldRequirementRemoved,
+		fieldUniquenessRemoved,
 	}
 
 	for _, comparison := range comparisons {
@@ -199,6 +203,28 @@ func fieldRequirementRemoved(old, new Dataset) (result []DatasetDifference) {
 	return append(result, compareFields(old, new, &difference, nil)...)
 }
 
+func fieldUniquenessRemoved(old, new Dataset) (result []DatasetDifference) {
+	var difference fieldEquivalentExists = func(
+		modelName, fieldName string,
+		oldField, newField Field,
+	) *DatasetDifference {
+		if oldField.Unique && !newField.Unique {
+			return &DatasetDifference{
+				Type:        DatasetDifferenceTypeFieldUniquenessRemoved,
+				Level:       DatasetDifferenceLevelField,
+				Severity:    DatasetDifferenceSeverityBreaking,
+				ModelName:   modelName,
+				FieldName:   fieldName,
+				Description: fmt.Sprintf("field uniqueness of '%v.%v' was removed", modelName, fieldName),
+			}
+		} else {
+			return nil
+		}
+	}
+
+	return append(result, compareFields(old, new, &difference, nil)...)
+}
+
 func equalStringPointers(s1, s2 *string) bool {
 	// both are the same (e.g. nil)
 	if s1 == s2 {

schema_test.go

@@ -113,6 +113,23 @@ func TestCompareDatasets(t *testing.T) {
 				Description: "field requirement of 'my_table.my_column' was removed",
 			}},
 		},
+		{
+			name: "fieldUniquenessRemoved",
+			args: args{
+				Dataset{Models: []Model{{Name: "my_table", Fields: []Field{
+					{Name: "my_column", Unique: true}}}}},
+				Dataset{Models: []Model{{Name: "my_table", Fields: []Field{
+					{Name: "my_column", Unique: false}}}}},
+			},
+			want: []DatasetDifference{{
+				Type:        DatasetDifferenceTypeFieldUniquenessRemoved,
+				Level:       DatasetDifferenceLevelField,
+				Severity:    DatasetDifferenceSeverityBreaking,
+				ModelName:   "my_table",
+				FieldName:   "my_column",
+				Description: "field uniqueness of 'my_table.my_column' was removed",
+			}},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {