test for small offset + build fix

.gitignore

@@ -2,4 +2,5 @@ test_data/*.log
 .idea
 .swo
 .swp
-.code
+.code
+release

Makefile

@@ -1,3 +1,6 @@
 rectail : cmd/rectail/args.go cmd/rectail/rectail.go
 	go test -v && go install ./cmd/rectail && echo 'installed to $$GOPATH/bin/rectail' && \
-	echo "to use, run 'rectail --help'"
+	echo "to use, run 'rectail --help'"
+
+test :
+	go test -v

rectail_test.go

@@ -153,3 +153,66 @@ func TestFirstRead(t *testing.T) {
 		}
 	}
 }
+
+func TestFirstReadForSmallOffset(t *testing.T) {
+	logger := log.New(logOutput, "", 0)
+
+	var (
+		fileUpdate    rectail.FileUpdate
+		expectedLines = []string{
+			"џѕѓ2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 џѕѓ2 bar2",
+			"џѕѓ3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 џѕѓ3 bar3",
+			"џѕѓ4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 џѕѓ4 bar4",
+		}
+		textToWrite = `џѕѓ bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar џѕѓ bar
+џѕѓ1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 foo1 bar1 џѕѓ1 bar1
+џѕѓ2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 foo2 bar2 џѕѓ2 bar2
+џѕѓ3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 foo3 bar3 џѕѓ3 bar3
+џѕѓ4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 foo4 bar4 џѕѓ4 bar4`
+		fileUpdates = make(chan rectail.FileUpdate)
+		updates     = make(chan string)
+		err         error
+		f           *os.File
+	)
+	f, err = os.Create("test_data/test.log")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err = f.WriteString(textToWrite); err != nil {
+		t.Fatal(err)
+	}
+
+	rt, err := rectail.NewRecTail(
+		[]string{"test_data"},
+		[]string{"\\.log"},
+		updates,
+		600,
+		400,
+		logger,
+	)
+	if err != nil {
+		t.Fatalf("could not initialize rectail: %v", err)
+	}
+	rectailCtx, rectailCtxCancel := context.WithCancel(context.Background())
+	defer rectailCtxCancel()
+
+	go func() {
+		if err = rt.Watch(rectailCtx, fileUpdates); err != nil {
+			logger.Fatalln(err)
+		}
+	}()
+	go func() {
+		for update := range updates {
+			logger.Println(update)
+		}
+	}()
+	fileUpdate = <-fileUpdates
+	if len(fileUpdate.Lines) != len(expectedLines) {
+		t.Errorf("expected %d lines with update; got: %d", len(expectedLines), len(fileUpdate.Lines))
+	}
+	for lineIndex := range fileUpdate.Lines {
+		if fileUpdate.Lines[lineIndex] != expectedLines[lineIndex] {
+			t.Errorf("expected: %s; got: %s", expectedLines[lineIndex], fileUpdate.Lines[lineIndex])
+		}
+	}
+}

release.sh

@@ -1,13 +1,14 @@
 #!/bin/bash
 
-tag=$(git describe --tags)
+releasePath="release"
+mkdir -p releasePath
 
-mkdir -p release/$tag
+GOOS=windows GOARCH=386 go build -o $releasePath/rectail.exe ./cmd/rectail
+GOOS=windows GOARCH=amd64 go build -o $releasePath/rectail64.exe ./cmd/rectail
 
-GOOS=windows GOARCH=386 go build -o release/$tag/rectail.exe ./cmd/rectail
-GOOS=windows GOARCH=amd64 go build -o release/$tag/rectail64.exe ./cmd/rectail
+GOOS=linux GOARCH=386 go build -o $releasePath/rectail_linux ./cmd/rectail
+GOOS=linux GOARCH=amd64 go build -o $releasePath/rectail64_linux ./cmd/rectail
 
-GOOS=linux GOARCH=386 go build -o release/$tag/rectail_linux ./cmd/rectail
-GOOS=linux GOARCH=amd64 go build -o release/$tag/rectail64_linux ./cmd/rectail
+GOOS=darwin GOARCH=amd64 go build -o $releasePath/rectail_osx ./cmd/rectail
 
-GOOS=darwin GOARCH=amd64 go build -o release/$tag/rectail_osx ./cmd/rectail
+echo "generated"