From 4cf804ae099740139e9b44f680a87f668ef800a9 Mon Sep 17 00:00:00 2001
From: Simon Waldherr <git@simon.waldherr.eu>
Date: Fri, 19 Oct 2018 20:51:21 +0200
Subject: [PATCH] add examples and test cases

---
 README.md       | 10 +++++-----
 example_test.go | 13 +++++++++++++
 zplgfa.go       |  9 +++++----
 zplgfa_test.go  | 11 +++++++++++
 4 files changed, 34 insertions(+), 9 deletions(-)
 create mode 100644 example_test.go
 create mode 100644 zplgfa_test.go

diff --git a/README.md b/README.md
index e0eef58..3b81789 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,10 @@
 # ZPLGFA Golang Package
 
-[![GoDoc](https://godoc.org/github.com/SimonWaldherr/zplgfa?status.svg)](https://godoc.org/github.com/SimonWaldherr/zplgfa)
-[![Go Report Card](https://goreportcard.com/badge/github.com/SimonWaldherr/zplgfa)](https://goreportcard.com/report/github.com/SimonWaldherr/zplgfa)
-[![codebeat badge](https://codebeat.co/badges/28d795af-6f9b-453a-94c2-4fafb8b5b0d5)](https://codebeat.co/projects/github-com-simonwaldherr-zplgfa-master)
-[![BCH compliance](https://bettercodehub.com/edge/badge/SimonWaldherr/zplgfa?branch=master)](https://bettercodehub.com/results/SimonWaldherr/zplgfa)
-[![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/SimonWaldherr/zplgfa/master/LICENSE)
+[![GoDoc](https://godoc.org/github.com/SimonWaldherr/zplgfa?status.svg)](https://godoc.org/github.com/SimonWaldherr/zplgfa) 
+[![Go Report Card](https://goreportcard.com/badge/github.com/SimonWaldherr/zplgfa)](https://goreportcard.com/report/github.com/SimonWaldherr/zplgfa) 
+[![codebeat badge](https://codebeat.co/badges/28d795af-6f9b-453a-94c2-4fafb8b5b0d5)](https://codebeat.co/projects/github-com-simonwaldherr-zplgfa-master) 
+[![BCH compliance](https://bettercodehub.com/edge/badge/SimonWaldherr/zplgfa?branch=master)](https://bettercodehub.com/results/SimonWaldherr/zplgfa) 
+[![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/SimonWaldherr/zplgfa/master/LICENSE) 
 
 The ZPLGFA Golang package implements some functions to convert PNG, JPEG and GIF files to ZPL compatible ^GF-elements ([Graphic Fields](https://www.zebra.com/us/en/support-downloads/knowledge-articles/gf-graphic-field-zpl-command.html)).
 
diff --git a/example_test.go b/example_test.go
new file mode 100644
index 0000000..a925e6c
--- /dev/null
+++ b/example_test.go
@@ -0,0 +1,13 @@
+package zplgfa_test
+
+import (
+	"fmt"
+	"simonwaldherr.de/go/zplgfa"
+)
+
+func ExampleCompressASCII() {
+	str := zplgfa.CompressASCII("FFFFFFFF000000")
+	fmt.Print(str)
+
+	// Output: NFL0
+}
diff --git a/zplgfa.go b/zplgfa.go
index f791224..d728a3f 100644
--- a/zplgfa.go
+++ b/zplgfa.go
@@ -87,7 +87,8 @@ func getRepeatCode(repeatCount int, char string) string {
 	return repeatStr
 }
 
-func compressASCII(in string) string {
+// CompressASCII compresses the ASCII data of a ZPL Graphic Field using RLE
+func CompressASCII(in string) string {
 	in = strings.ToUpper(in)
 	var curChar string
 	var lastChar string
@@ -112,7 +113,7 @@ func compressASCII(in string) string {
 			curChar = string(in[i])
 		}
 		if lastChar != curChar {
-			if i-lastCharSince > 8 {
+			if i-lastCharSince > 4 {
 				repCode = getRepeatCode(i-lastCharSince, lastChar)
 				output += repCode
 			} else {
@@ -175,7 +176,7 @@ func ConvertToGraphicField(source image.Image, graphicType GraphicType) string {
 		case ASCII:
 			GraphicFieldData += fmt.Sprintln(hexstr)
 		case CompressedASCII:
-			curLine := compressASCII(hexstr)
+			curLine := CompressASCII(hexstr)
 			if lastLine == curLine {
 				GraphicFieldData += ":"
 			} else {
@@ -186,7 +187,7 @@ func ConvertToGraphicField(source image.Image, graphicType GraphicType) string {
 			GraphicFieldData += fmt.Sprintf("%s", line)
 		default:
 			graphicType = CompressedASCII
-			GraphicFieldData += fmt.Sprintln(compressASCII(hexstr))
+			GraphicFieldData += fmt.Sprintln(CompressASCII(hexstr))
 		}
 	}
 
diff --git a/zplgfa_test.go b/zplgfa_test.go
new file mode 100644
index 0000000..bde8965
--- /dev/null
+++ b/zplgfa_test.go
@@ -0,0 +1,11 @@
+package zplgfa
+
+import (
+	"testing"
+)
+
+func Test_CompressASCII(t *testing.T) {
+	if str := CompressASCII("FFFFFFFF000000"); str != "NFL0" {
+		t.Fatalf("CompressASCII failed")
+	}
+}