xl: heal bucket should validate if bucket exists first. (#2953)

Fixes #2944

cmd/xl-v1-healing-common_test.go

@@ -0,0 +1,83 @@
+/*
+ * 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 cmd
+
+import (
+	"testing"
+	"time"
+)
+
+// validates functionality provided to find most common
+// time occurrence from a list of time.
+func TestCommonTime(t *testing.T) {
+	// List of test cases for common modTime.
+	testCases := []struct {
+		times []time.Time
+		time  time.Time
+	}{
+		{
+			// 1. Tests common times when slice has varying time elements.
+			[]time.Time{
+				time.Unix(0, 1).UTC(),
+				time.Unix(0, 2).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 2).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 1).UTC(),
+			}, time.Unix(0, 3).UTC(),
+		},
+		{
+			// 2. Tests common time obtained when all elements are equal.
+			[]time.Time{
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+			}, time.Unix(0, 3).UTC(),
+		},
+		{
+			// 3. Tests common time obtained when elements have a mixture
+			// of sentinel values.
+			[]time.Time{
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 2).UTC(),
+				time.Unix(0, 1).UTC(),
+				time.Unix(0, 3).UTC(),
+				time.Unix(0, 4).UTC(),
+				time.Unix(0, 3).UTC(),
+				timeSentinel,
+				timeSentinel,
+				timeSentinel,
+			}, time.Unix(0, 3).UTC(),
+		},
+	}
+
+	// Tests all the testcases, and validates them against expected
+	// common modtime. Tests fail if modtime does not match.
+	for i, testCase := range testCases {
+		// Obtain a common mod time from modTimes slice.
+		ctime := commonTime(testCase.times)
+		if testCase.time != ctime {
+			t.Fatalf("Test case %d, expect to pass but failed. Wanted modTime: %s, got modTime: %s\n", i+1, testCase.time, ctime)
+		}
+	}
+}