Add more unit tests

.gitignore

@@ -1,6 +1,4 @@
 items/
-README.tpl
-
 dist/
 bin/
 .idea/

function/data/README-group.tpl

@@ -0,0 +1,8 @@
+{{- range $key, $val := .}}
+Year: {{$key}}
+| Zh | En |
+|---|---|
+{{- range $item := $val}}
+| {{$item.zh}} | {{$item.en}} |
+{{- end}}
+{{end}}

function/data/README.tpl

@@ -0,0 +1,5 @@
+|中文名称|英文名称|JD|
+|---|---|---|
+{{- range $val := .}}
+|{{$val.zh}}|{{$val.en}}|{{$val.jd}}|
+{{- end}}

function/data/item-2022.yaml

@@ -0,0 +1,4 @@
+zh: zh
+en: en
+jd: jd
+year: 2022

function/data/item-ignore.yaml

@@ -0,0 +1,4 @@
+zh: zh
+en: en
+jd: jd
+ignore: true

function/data/item.yaml

@@ -0,0 +1,4 @@
+zh: zh
+en: en
+jd: jd
+year: 2021

main.go

@@ -10,6 +10,7 @@ import (
 	"html/template"
 	"io"
 	"io/ioutil"
+	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -18,6 +19,8 @@ import (
 	"strings"
 )
 
+var logger *log.Logger
+
 type option struct {
 	pattern       string
 	templateFile  string
@@ -29,33 +32,23 @@ type option struct {
 	printVariables bool
 }
 
-func (o *option) runE(cmd *cobra.Command, args []string) (err error) {
-	if o.printFunctions {
-		printFunctions(cmd.OutOrStdout())
-		return
-	}
-
-	if o.printVariables {
-		printVariables(cmd.OutOrStdout())
-		return
-	}
-
-	var items []map[string]interface{}
-	groupData := make(map[string][]map[string]interface{})
+func loadMetadata(pattern, groupBy string) (items []map[string]interface{},
+	groupData map[string][]map[string]interface{}, err error) {
+	groupData = make(map[string][]map[string]interface{})
 
 	// find YAML files
 	var files []string
 	var data []byte
-	if files, err = filepath.Glob(o.pattern); err == nil {
+	if files, err = filepath.Glob(pattern); err == nil {
 		for _, metaFile := range files {
 			if data, err = ioutil.ReadFile(metaFile); err != nil {
-				cmd.PrintErrf("failed to read file [%s], error: %v\n", metaFile, err)
+				logger.Printf("failed to read file [%s], error: %v\n", metaFile, err)
 				continue
 			}
 
 			metaMap := make(map[string]interface{})
 			if err = yaml.Unmarshal(data, metaMap); err != nil {
-				cmd.PrintErrf("failed to parse file [%s] as a YAML, error: %v\n", metaFile, err)
+				logger.Printf("failed to parse file [%s] as a YAML, error: %v\n", metaFile, err)
 				continue
 			}
 
@@ -73,7 +66,7 @@ func (o *option) runE(cmd *cobra.Command, args []string) (err error) {
 			metaMap["parentname"] = parentname
 			metaMap["fullpath"] = metaFile
 
-			if val, ok := metaMap[o.groupBy]; ok && val != "" {
+			if val, ok := metaMap[groupBy]; ok && val != "" {
 				var strVal string
 				switch val.(type) {
 				case string:
@@ -94,39 +87,74 @@ func (o *option) runE(cmd *cobra.Command, args []string) (err error) {
 			items = append(items, metaMap)
 		}
 	}
+	return
+}
 
-	if o.sortBy != "" {
-		descending := true
-		if strings.HasPrefix(o.sortBy, "!") {
-			o.sortBy = strings.TrimPrefix(o.sortBy, "!")
-			descending = false
-		}
-		sortBy(items, o.sortBy, descending)
+func sortMetadata(items []map[string]interface{}, sortByField string) {
+	descending := true
+	if strings.HasPrefix(sortByField, "!") {
+		sortByField = strings.TrimPrefix(sortByField, "!")
+		descending = false
 	}
+	sortBy(items, sortByField, descending)
+}
 
+func loadTemplate(templateFile string, includeHeader bool) (readmeTpl string, err error) {
 	// load readme template
-	var readmeTpl string
-	if data, err = ioutil.ReadFile(o.templateFile); err != nil {
+	var data []byte
+	if data, err = ioutil.ReadFile(templateFile); err != nil {
 		fmt.Printf("failed to load README template, error: %v\n", err)
-		readmeTpl = `
-|中文名称|英文名称|JD|
+		err = nil
+		readmeTpl = `|中文名称|英文名称|JD|
 |---|---|---|
 {{- range $val := .}}
 |{{$val.zh}}|{{$val.en}}|{{$val.jd}}|
-{{end}}
-`
+{{- end}}`
 	}
-	if o.includeHeader {
+	if includeHeader {
 		readmeTpl = fmt.Sprintf("> This file was generated by [%s](%s) via [yaml-readme](https://github.com/LinuxSuRen/yaml-readme), please don't edit it directly!\n\n",
-			filepath.Base(o.templateFile), filepath.Base(o.templateFile))
+			filepath.Base(templateFile), filepath.Base(templateFile))
 	}
 	readmeTpl = readmeTpl + string(data)
+	return
+}
+
+func (o *option) runE(cmd *cobra.Command, args []string) (err error) {
+	logger = log.New(cmd.OutOrStdout(), "", log.LstdFlags)
+	if o.printFunctions {
+		printFunctions(cmd.OutOrStdout())
+		return
+	}
+
+	if o.printVariables {
+		printVariables(cmd.OutOrStdout())
+		return
+	}
+
+	// load metadata from YAML files
+	var items []map[string]interface{}
+	var groupData map[string][]map[string]interface{}
+	if items, groupData, err = loadMetadata(o.pattern, o.groupBy); err != nil {
+		err = fmt.Errorf("failed to load metadat from %q", o.pattern)
+		return
+	}
+
+	if o.sortBy != "" {
+		sortMetadata(items, o.sortBy)
+	}
+
+	// load readme template
+	var readmeTpl string
+	if readmeTpl, err = loadTemplate(o.templateFile, o.includeHeader); err != nil {
+		err = fmt.Errorf("failed to load template file from %q", o.templateFile)
+		return
+	}
 
 	// render it with grouped data
 	if o.groupBy != "" {
-		err = renderTemplate(readmeTpl, groupData, os.Stdout)
+		err = renderTemplate(readmeTpl, groupData, cmd.OutOrStdout())
 	} else {
-		err = renderTemplate(readmeTpl, items, os.Stdout)
+		err = renderTemplate(readmeTpl, items, cmd.OutOrStdout())
 	}
 	return
 }
@@ -157,9 +185,14 @@ fullpath`))
 
 func printFunctions(stdout io.Writer) {
 	funcMap := getFuncMap("")
+	var funcs []string
 	for k := range funcMap {
-		_, _ = stdout.Write([]byte(fmt.Sprintf("%s\n", k)))
+		funcs = append(funcs, k)
 	}
+	sort.SliceStable(funcs, func(i, j int) bool {
+		return strings.Compare(funcs[i], funcs[j]) < 0
+	})
+	_, _ = stdout.Write([]byte(strings.Join(funcs, "\n")))
 }
 
 func getFuncMap(readmeTpl string) template.FuncMap {
@@ -260,13 +293,14 @@ func dataRender(data interface{}) string {
 	return ""
 }
 
-func main() {
+func newRootCommand() (cmd *cobra.Command) {
 	opt := &option{}
-	cmd := cobra.Command{
+	cmd = &cobra.Command{
 		Use:   "yaml-readme",
 		Short: "A helper to generate a README file from Golang-based template",
 		RunE:  opt.runE,
 	}
+	cmd.SetOut(os.Stdout)
 	flags := cmd.Flags()
 	flags.StringVarP(&opt.pattern, "pattern", "p", "items/*.yaml",
 		"The glob pattern with Golang spec to find files")
@@ -282,9 +316,11 @@ func main() {
 		"Print all the functions and exit")
 	flags.BoolVarP(&opt.printVariables, "print-variables", "", false,
 		"Print all the variables and exit")
+	return
+}
 
-	err := cmd.Execute()
-	if err != nil {
+func main() {
+	if err := newRootCommand().Execute(); err != nil {
 		os.Exit(1)
 	}
 }