fix: add more test for transformer

transform/transformer_test.go

@@ -1,9 +1,12 @@
 package transform
 
 import (
+	"github.com/karlderkaefer/cdk-notifier/config"
 	"github.com/stretchr/testify/assert"
+	"math/rand"
 	"os"
 	"testing"
+	"time"
 )
 
 func TestLogTransformer_ReadFile(t *testing.T) {
@@ -115,4 +118,82 @@ func TestLogTransformer_WriteDiffFile(t *testing.T) {
 	assert.NoError(t, err)
 	assert.FileExistsf(t, fileDiff, "Expect diff file to be found")
 
+	transformer.Logfile = "/tmp/nonexisting-dir/nofile"
+	err = transformer.writeDiffFile()
+	assert.Error(t, err)
+}
+
+type TruncateTest struct {
+	runeCount      int
+	expectedLength int
+	exceeds        bool
+}
+
+func randomStringRunes(n int) string {
+	rand.Seed(time.Now().UnixNano())
+	var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letterRunes[rand.Intn(len(letterRunes))]
+	}
+	return string(b)
+}
+
+func TestLogTransform_Truncate(t *testing.T) {
+	testCases := []TruncateTest{
+		{
+			runeCount:      0,
+			expectedLength: 0,
+			exceeds:        false,
+		},
+		{
+			runeCount:      100,
+			expectedLength: 100,
+			exceeds:        false,
+		},
+		{
+			runeCount:      65000,
+			expectedLength: 65000,
+			exceeds:        false,
+		},
+		{
+			runeCount:      78999,
+			expectedLength: 65000,
+			exceeds:        true,
+		},
+		{
+			runeCount:      878999,
+			expectedLength: 65000,
+			exceeds:        true,
+		},
+	}
+	transformer := &LogTransformer{}
+
+	for _, c := range testCases {
+		truncatedLog := "\n...truncated"
+		transformer.LogContent = randomStringRunes(c.runeCount)
+		transformer.truncate()
+		if c.exceeds {
+			assert.Equal(t, c.expectedLength+len(truncatedLog), len(transformer.LogContent))
+		} else {
+			assert.Equal(t, c.expectedLength, len(transformer.LogContent))
+		}
+	}
+}
+
+func TestNewLogTransformer(t *testing.T) {
+	c := &config.NotifierConfig{
+		LogFile:    "../data/cdk-nochanges.log",
+		TagID:      "small",
+		NoPostMode: false,
+	}
+	transformer := NewLogTransformer(c)
+	assert.NotNil(t, transformer)
+	assert.Equal(t, transformer.LogContent, "")
+	assert.Equal(t, transformer.TagID, "small")
+	assert.Equal(t, transformer.NoPostMode, false)
+
+	transformer.Process()
+	assert.Contains(t, transformer.LogContent, "Stack SuiteRedisStack\nThere were no differences")
+
 }