Add tests for Damerau Levenshtein algorithm (#2407)

damerau-levenshtein_test.go

@@ -0,0 +1,66 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"math"
+	"testing"
+)
+
+// Test minimum function which calculates the minimal value in a list of integers
+func TestMinimum(t *testing.T) {
+	type testCase struct {
+		listval  []int
+		expected int
+		pass     bool
+	}
+	testCases := []testCase{
+		{listval: []int{3, 4, 15}, expected: 3},
+		{listval: []int{}, expected: math.MaxInt32},
+	}
+	// Validate all the test cases.
+	for i, tt := range testCases {
+		val := minimum(tt.listval)
+		if val != tt.expected {
+			t.Errorf("Test %d:, Expected %d, got %d", i+1, tt.expected, val)
+		}
+	}
+}
+
+// Test DamerauLevenshtein which calculates the difference distance between two words
+func TestDamerauLevenshtein(t *testing.T) {
+	type testCase struct {
+		word1    string
+		word2    string
+		distance int
+	}
+	testCases := []testCase{
+		{word1: "", word2: "", distance: 0},
+		{word1: "a", word2: "a", distance: 0},
+		{word1: "a", word2: "b", distance: 1},
+		{word1: "rm", word2: "tm", distance: 1},
+		{word1: "version", word2: "evrsion", distance: 1},
+		{word1: "version", word2: "bersio", distance: 2},
+	}
+	// Validate all the test cases.
+	for i, tt := range testCases {
+		d := DamerauLevenshteinDistance(tt.word1, tt.word2)
+		if d != tt.distance {
+			t.Errorf("Test %d:, Expected %d, got %d", i+1, tt.distance, d)
+		}
+	}
+}