chore(ENT-923): add priority comparison methods (#171)

* chore(ENT-923): add priority comparison methods

* chore(ENT-923): add unit test

Author: juicetin

pkg/models/priority.go

@@ -5,3 +5,30 @@ const (
 	PriorityImportant     string = "IMPORTANT"
 	PriorityInformational string = "INFORMATIONAL"
 )
+
+var priorityToInt = map[string]int{
+	PriorityInformational: 0,
+	PriorityImportant:     1,
+	PriorityUrgent:        2,
+}
+
+func ComparePriority(priority1, priority2 string) int {
+	val1, ok1 := priorityToInt[priority1]
+	val2, ok2 := priorityToInt[priority2]
+
+	if !ok1 && !ok2 {
+		return 0
+	} else if !ok1 {
+		return -1
+	} else if !ok2 {
+		return 1
+	}
+
+	if val1 < val2 {
+		return -1
+	} else if val1 > val2 {
+		return 1
+	} else {
+		return 0
+	}
+}

pkg/models/priority_test.go

@@ -0,0 +1,32 @@
+package models
+
+import "testing"
+
+func TestComparePriority(t *testing.T) {
+	tests := []struct {
+		priority1 string
+		priority2 string
+		expected  int
+	}{
+		{"INVALID", "URGENT", -1},
+		{"UNKNOWN", "IMPORTANT", -1},
+		{"INFORMATIONAL", "URGENT", -1},
+		{"IMPORTANT", "URGENT", -1},
+		{"URGENT", "IMPORTANT", 1},
+		{"IMPORTANT", "INFORMATIONAL", 1},
+		{"URGENT", "UNKNOWN", 1},
+		{"IMPORTANT", "INVALID", 1},
+		{"UNKNOWN", "UNKNOWN", 0},
+		{"INFORMATIONAL", "INFORMATIONAL", 0},
+		{"IMPORTANT", "IMPORTANT", 0},
+		{"URGENT", "URGENT", 0},
+	}
+
+	for _, test := range tests {
+		result := ComparePriority(test.priority1, test.priority2)
+		if result != test.expected {
+			t.Errorf("ComparePriority(%s, %s) = %d; want %d",
+				test.priority1, test.priority2, result, test.expected)
+		}
+	}
+}