Create test for ReadData.

hack/test-flake-chart/compute_flake_rate.go

@@ -62,7 +62,7 @@ type TestEntry struct {
 }
 
 // Reads CSV `file` and consumes each line to be a single TestEntry.
-func ReadData(file *os.File) []TestEntry {
+func ReadData(file io.Reader) []TestEntry {
 	testEntries := []TestEntry{}
 
 	fileReader := bufio.NewReaderSize(file, 256)

hack/test-flake-chart/compute_flake_rate_test.go

@@ -0,0 +1,87 @@
+/*
+Copyright 2020 The Kubernetes Authors All rights reserved.
+
+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 (
+	"strings"
+	"testing"
+	"time"
+)
+
+func simpleDate(year int, month time.Month, day int) time.Time {
+	return time.Date(year, month, day, 0, 0, 0, 0, time.UTC)
+}
+
+func TestReadData(t *testing.T) {
+	actualData := ReadData(strings.NewReader(
+		`A,B,C,D,E,F
+		hash,2000-01-01,env1,test1,Passed,1
+		hash,2001-01-01,env2,test2,Failed,1
+		hash,,,test1,,1
+		hash,2002-01-01,,,Passed,1
+		hash,2003-01-01,env3,test3,Passed,1`,
+	))
+	expectedData := []TestEntry{
+		{
+			name:        "test1",
+			environment: "env1",
+			date:        simpleDate(2000, time.January, 1),
+			status:      "Passed",
+		},
+		{
+			name:        "test2",
+			environment: "env2",
+			date:        simpleDate(2001, time.January, 1),
+			status:      "Failed",
+		},
+		{
+			name:        "test1",
+			environment: "env2",
+			date:        simpleDate(2001, time.January, 1),
+			status:      "Failed",
+		},
+		{
+			name:        "test1",
+			environment: "env2",
+			date:        simpleDate(2002, time.January, 1),
+			status:      "Passed",
+		},
+		{
+			name:        "test3",
+			environment: "env3",
+			date:        simpleDate(2003, time.January, 1),
+			status:      "Passed",
+		},
+	}
+
+	for i, actual := range actualData {
+		if len(expectedData) <= i {
+			t.Errorf("Received unmatched actual element at index %d. Actual: %v", i, actual)
+			continue
+		}
+		expected := expectedData[i]
+		if actual != expected {
+			t.Errorf("Elements differ at index %d. Expected: %v, Actual: %v", i, expected, actual)
+		}
+	}
+
+	if len(actualData) < len(expectedData) {
+		for i := len(actualData); i < len(expectedData); i++ {
+			t.Errorf("Missing unmatched expected element at index %d. Expected: %v", i, expectedData[i])
+		}
+	}
+}