Improves args handling and fixes np when line has no leading star

CHANGELOG.md

@@ -4,11 +4,27 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.0] - 2020-11-09
+### Added
+- 🎉 new flag `-images-type` to specify a default suffix for all the images
+  - specifying this flag when including images, you can omit the extension 
+  - example: if flag has `-images-type png`, you can write `[[bulb]]` instead of `[[build.png]]`
+
+### Changed
+- updated the README markdown file
+- improve argument parsing
+  - when invoked without args, an attempt is made to read from standard input
+
+### Fixed
+- 🐛 Line with no leading stars causes nil pointer dereference [#2](/issues/#2) 
+
 ## [0.2.0] - 2020-09-09
 ### Added
 - 📝 more test cases
 - 🎉 new flag `images-path` to specify the base images folder
   - now when including images, you can specify just the filename
+  - example: if flag has `-images-path '/Icons/AwesomFonts'`, you can write `[[bulb.png]]` instead of `[[/Icons/AwesomFonts/build.png]]`
+
 - 🎉 new flag `lim` to specify after how many characters to wrap the text
 
 ### Changed

README.md

@@ -56,8 +56,9 @@ Here the output:
 
 You can, eventually, add images too (one for text line) using a special syntax: `[[path/to/image.png]]`
 
-- starting from the release v0.2.0 you can specify the image path from the command line `-image-path` flag
-- if you specify the flag `-image-path` you can wriate `[[image.png]]` instead of `[[path/to/image.png]]`
+- if you specify the flag `-image-path` you can write `[[image.png]]` instead of `[[path/to/image.png]]`
+- if you specify the flag `-image-type` you can write `[[path/to/image]]` instead of `[[path/to/image.png]]`
+- therefore if you specify both you can write `[[image]]` instead of `[[path/to/image.png]]`
 
 ```text
 * [[./png/bulb.png]] main idea

crumbs/main.go

@@ -32,6 +32,7 @@ var (
 	flagVertical   bool
 	flagWrapLim    uint
 	flagImagesPath string
+	flagImagesType string
 )
 
 func main() {
@@ -69,23 +70,22 @@ func readEntry() (*crumbs.Entry, error) {
 	}
 	text := string(src)
 	lines := strings.SplitAfter(text, "\n")
-	return crumbs.ParseLines(lines, flagImagesPath)
+	return crumbs.ParseLines(lines, flagImagesPath, flagImagesType)
 }
 
 func readFileObject(r io.Reader, limit int64) ([]byte, error) {
 	lr := io.LimitReader(r, limit)
-	src, err := ioutil.ReadAll(lr)
-	return src, err
+	return ioutil.ReadAll(lr)
 }
 
 func readFile(name string, limit int64) ([]byte, error) {
 	r, err := os.Open(name)
 	if err != nil {
 		return nil, err
 	}
-	src, err := readFileObject(r, limit)
-	r.Close()
-	return src, err
+	defer r.Close()
+
+	return readFileObject(r, limit)
 }
 
 func configureFlags() {
@@ -117,8 +117,8 @@ func configureFlags() {
 		"layout entries as vertical directed graph")
 	flag.CommandLine.UintVar(&flagWrapLim, "lim", 28, "wraps each line within this width in characters")
 
-	flag.CommandLine.StringVar(&flagImagesPath, "images-path", "./", "folder in which to look for image files")
-	//flag.CommandLine.StringVar(&flagImagesType, "images-type", "png", "images file extension [png,jpg,svg]")
+	flag.CommandLine.StringVar(&flagImagesPath, "images-path", "", "folder in which to look for image files")
+	flag.CommandLine.StringVar(&flagImagesType, "images-type", "", "images file extension [png,jpg,svg]")
 
 	flag.CommandLine.Parse(os.Args[1:])
 }

parser.go

@@ -1,6 +1,7 @@
 package crumbs
 
 import (
+	"fmt"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -9,9 +10,9 @@ import (
 )
 
 // ParseLines parses a slice of text lines and builds the tree.
-func ParseLines(lines []string, iconspath string) (*Entry, error) {
+func ParseLines(lines []string, imagesPath, imagesSuffix string) (*Entry, error) {
 	mkID := idGenerator()
-	checkIcon := lookForIcon(iconspath)
+	checkIcon := lookForIcon(imagesPath, imagesSuffix)
 
 	// generate a short id for the root node
 	rootID, err := mkID()
@@ -33,6 +34,11 @@ func ParseLines(lines []string, iconspath string) (*Entry, error) {
 		// count depth
 		childDepth := depth(el)
 
+		// case: no leading 'stars' (skip line)
+		if childDepth == 0 {
+			continue
+		}
+
 		// trim leading 'stars', then the spaces
 		text := el[childDepth:]
 		text = strings.TrimSpace(text)
@@ -118,14 +124,17 @@ func idGenerator() func() (string, error) {
 	}
 }
 
-func lookForIcon(iconspath string) func(note *Entry) {
+func lookForIcon(imagesPath, imagesSuffix string) func(note *Entry) {
 	re := regexp.MustCompile(`^\[{2}(.*?)\]{2}`)
 
 	return func(note *Entry) {
 		str := note.text
 		res := re.FindStringSubmatch(str)
 		if len(res) > 0 {
-			note.icon = filepath.Join(iconspath, strings.TrimSpace(res[1]))
+			note.icon = filepath.Join(imagesPath, strings.TrimSpace(res[1]))
+			if len(imagesSuffix) > 0 {
+				note.icon = fmt.Sprintf("%s.%s", note.icon, imagesSuffix)
+			}
 			note.text = re.ReplaceAllString(str, "")
 		}
 	}

testdata/when-to-use-crumbs-icons-no-path-ext.txt

@@ -0,0 +1,21 @@
+* When to use "crumbs"
+
+** [[bulb]] to generate ideas
+*** to search for patterns
+*** to speculate and explore ideas
+*** to merge ideas
+
+** [[comments-alt]] to communicate
+*** to demostrate a structure
+*** to show your thoughts to others
+*** to record a meeting
+
+** [[book-reader]] to learn
+*** to record a lecture
+*** to prepare a paper
+*** to study for exams and certifications
+
+** [[map-signs]] to make decisions
+*** to analyze problems
+*** to get team's input
+*** to record multiple ideas