From 7316c796b5ae73cc3b4414ea44889a49b03d6152 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20H=C3=B6ltje?= <docwhat@gerf.org>
Date: Tue, 15 Mar 2022 23:19:42 -0400
Subject: [PATCH] chore: replace kinpin with kong CLI library

---
 README.md    | 18 +++++------
 functions.go | 20 +++++--------
 go.mod       | 24 +++++++++++++--
 go.sum       | 85 +++++++++++++++++++++++++++++++++++++++++++++++-----
 main.go      | 82 +++++++++++++++++---------------------------------
 utils.go     | 15 ----------
 6 files changed, 144 insertions(+), 100 deletions(-)
 delete mode 100644 utils.go

diff --git a/README.md b/README.md
index ecc563f..9c793f9 100644
--- a/README.md
+++ b/README.md
@@ -30,18 +30,18 @@ go install docwhat.org/temple
 
 ## Usage
 
-    usage: temple [<flags>] <template>
+    Usage: temple <template-file>
 
-    Fast and simple templating engine
+    A simple templating engine
 
-    Flags:
-      -h, --help            Show context-sensitive help (also try --help-long and --help-man).
-          --version         Show application version.
-      -d, --data=DATA-FILE  A YAML or JSON file to use via the {{data.<foo>}} interface (Env: TEMPLE_DATA_FILE)
-      -H, --html            Use HTML templating instead of text templating (Env: TEMPLE_HTML)
+    Arguments:
+      <template-file>    The template file to use ($TEMPLE_TEMPLATE_FILE)
 
-    Args:
-      <template>  A Go Template file.
+    Flags:
+      -h, --help              Show context-sensitive help.
+          --version           Show version information
+      -d, --data=DATA-FILE    A YAML or JSON file to use via the {{data.<foo>}} interface ($TEMPLE_DATA_FILE)
+      -H, --html              Use HTML templating instead of text templating ($TEMPLE_USE_HTML)
 
 Note that the `DATA` file must have an object at the top level. You cannot use a bare string or an array.
 
diff --git a/functions.go b/functions.go
index f9641f9..c0b877b 100644
--- a/functions.go
+++ b/functions.go
@@ -17,7 +17,7 @@ import (
 // FuncMap is the same as implemented in text/template and html/template.
 type FuncMap map[string]interface{}
 
-func buildFuncMap(dataFile string) (FuncMap, error) {
+func buildFuncMap(dataFile *os.File) (FuncMap, error) {
 	var err error
 
 	funcMap := make(FuncMap)
@@ -39,26 +39,22 @@ func buildFuncMap(dataFile string) (FuncMap, error) {
 	return funcMap, nil
 }
 
-func dataFunc(dataFileName string) (func() FuncMap, error) {
+func dataFunc(dataFile *os.File) (func() FuncMap, error) {
 	var dataFunctionMap map[string]interface{}
 
-	if dataFileName != "" {
-		file := safeOpen(dataFileName)
+	if dataFile != nil {
 		defer func() {
-			if err := file.Close(); err != nil {
-				log.Printf("unable to close file %v: %s", dataFileName, err)
+			if err := dataFile.Close(); err != nil {
+				log.Printf("unable to close data file: %s", err)
 			}
 		}()
 
-		dec := yaml.NewDecoder(file)
-		if err := dec.Decode(&dataFunctionMap); err != nil {
-			return nil, fmt.Errorf("unable to parse %s: %w", dataFileName, err)
+		if err := yaml.NewDecoder(dataFile).Decode(&dataFunctionMap); err != nil {
+			return nil, fmt.Errorf("unable to parse data file: %w", err)
 		}
 	}
 
-	dm := func() FuncMap { return dataFunctionMap }
-
-	return dm, nil
+	return func() FuncMap { return dataFunctionMap }, nil
 }
 
 func doTextTemplate(file string, funcMap FuncMap, emitter io.Writer) error {
diff --git a/go.mod b/go.mod
index 64cbef5..a14ed56 100644
--- a/go.mod
+++ b/go.mod
@@ -5,22 +5,40 @@ go 1.17
 require (
 	github.com/Masterminds/sprig/v3 v3.2.2
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
-	gopkg.in/alecthomas/kingpin.v2 v2.2.6
+	github.com/spf13/pflag v1.0.5
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
+	github.com/BurntSushi/toml v1.0.0 // indirect
 	github.com/Masterminds/goutils v1.1.1 // indirect
 	github.com/Masterminds/semver/v3 v3.1.1 // indirect
-	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
-	github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 // indirect
+	github.com/alecthomas/kong v0.5.0 // indirect
+	github.com/fsnotify/fsnotify v1.5.1 // indirect
 	github.com/google/uuid v1.3.0 // indirect
+	github.com/hedzr/cmdr v1.10.33 // indirect
+	github.com/hedzr/cmdr-base v0.1.3 // indirect
+	github.com/hedzr/log v1.5.31 // indirect
+	github.com/hedzr/logex v1.5.31 // indirect
 	github.com/huandu/xstrings v1.3.2 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
+	github.com/konsorten/go-windows-terminal-sequences v1.0.3 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/rs/zerolog v1.26.1 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
+	github.com/sirupsen/logrus v1.8.1 // indirect
 	github.com/spf13/cast v1.4.1 // indirect
 	github.com/stretchr/testify v1.7.0 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	go.uber.org/multierr v1.6.0 // indirect
+	go.uber.org/zap v1.21.0 // indirect
 	golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000 // indirect
+	golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2 // indirect
+	golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e // indirect
+	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 // indirect
+	gopkg.in/hedzr/errors.v3 v3.0.11 // indirect
+	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
diff --git a/go.sum b/go.sum
index 479d858..b8bfb04 100644
--- a/go.sum
+++ b/go.sum
@@ -1,19 +1,33 @@
+github.com/BurntSushi/toml v1.0.0 h1:dtDWrepsVPfW9H/4y7dDgFc2MBUSeJhlaDtK13CxFlU=
+github.com/BurntSushi/toml v1.0.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/Masterminds/goutils v1.1.1 h1:5nUrii3FMTL5diU80unEVvNevw1nH4+ZV4DSLVJLSYI=
 github.com/Masterminds/goutils v1.1.1/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy863GQaJW2MFNU=
 github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/Masterminds/sprig/v3 v3.2.2 h1:17jRggJu518dr3QaafizSXOjKYp94wKfABxUmyxvxX8=
 github.com/Masterminds/sprig/v3 v3.2.2/go.mod h1:UoaO7Yp8KlPnJIYWTFkMaqPUYKTfGFPhxNuwnnxkKlk=
-github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 h1:JYp7IbQjafoB+tBA3gMyHYHrpOtNuDiK/uB5uXxq5wM=
-github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
-github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 h1:s6gZFSlWYmbqAuRjVTiNNhvNRfY2Wxp9nhfyel4rklc=
-github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137/go.mod h1:OMCwj8VM1Kc9e19TLln2VL61YJF0x1XFtfdL4JdbSyE=
+github.com/alecthomas/kong v0.5.0 h1:u8Kdw+eeml93qtMZ04iei0CFYve/WPcA5IFh+9wSskE=
+github.com/alecthomas/kong v0.5.0/go.mod h1:uzxf/HUh0tj43x1AyJROl3JT7SgsZ5m+icOv1csRhc0=
+github.com/alecthomas/repr v0.0.0-20210801044451-80ca428c5142/go.mod h1:2kn6fqh/zIyPLmm3ugklbEi5hg5wS435eygvNfaDQL8=
+github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/coreos/go-systemd/v22 v22.3.2/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.5.1 h1:mZcQUHVQUQWoPXXtuf9yuEXKudkV2sx1E06UadKWpgI=
+github.com/fsnotify/fsnotify v1.5.1/go.mod h1:T3375wBYaZdLLcVNkcVbzGHY7f1l/uK5T5Ai1i3InKU=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/hedzr/cmdr v1.10.33 h1:15mNefD0V0uYZeXnDzWQ5QlqbLnH7Ld3a5n0FST3hxM=
+github.com/hedzr/cmdr v1.10.33/go.mod h1:Vr5gSL+tkTSLF1ma5F3hkrcnWHP7Mq6TY3mOfr9IdE0=
+github.com/hedzr/cmdr-base v0.1.3 h1:pMhVLP+Uxdhuf6BeasAC2OivMXJ3vxJHvFJHPQscQPU=
+github.com/hedzr/cmdr-base v0.1.3/go.mod h1:c3vMkHa5PME2P2W8lE3T9+JX12tq9tmCUt6lXbmt5kI=
+github.com/hedzr/log v1.5.31 h1:rHi8L7yqHnasnE/izSyz3k0mhp8vyZJvSu5Pbht/7Ps=
+github.com/hedzr/log v1.5.31/go.mod h1:IdcEUJ+Ae6VhtxSR0ZWAPhLGD9f1otXPAnUJ9QXaOJg=
+github.com/hedzr/logex v1.5.31 h1:j14jzQ+XcEJ40P/kUWGZenL5w4M2TZWw2HPW0S6tbfs=
+github.com/hedzr/logex v1.5.31/go.mod h1:jXUQ9vtdvJm/BGKwuxmVea3I/Bf3kFHUsnBTz7gADoI=
 github.com/huandu/xstrings v1.3.1/go.mod h1:y5/lhBue+AyNmUVz9RLU9xbLR0o4KIIExikq4ovT0aE=
 github.com/huandu/xstrings v1.3.2 h1:L18LIDzqlW6xN2rEkpdV8+oL/IXWJ1APd+vsdYy4Wdw=
 github.com/huandu/xstrings v1.3.2/go.mod h1:y5/lhBue+AyNmUVz9RLU9xbLR0o4KIIExikq4ovT0aE=
@@ -22,48 +36,105 @@ github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/mitchellh/copystructure v1.0.0/go.mod h1:SNtv71yrdKgLRyLFxmLdkAbkKEFWgYaq1OVrnRcwhnw=
 github.com/mitchellh/copystructure v1.2.0 h1:vpKXTN4ewci03Vljg/q9QvCGUDttBOGBIa15WveJJGw=
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 github.com/shopspring/decimal v1.3.1 h1:2Usl1nmF/WZucqkFZhnfFYxxxu8LG21F6nPQBE5gKV8=
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 golang.org/x/crypto v0.0.0-20200414173820-0848c9571904/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
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 golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
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 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
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diff --git a/main.go b/main.go
index 883e580..abe5613 100644
--- a/main.go
+++ b/main.go
@@ -2,10 +2,9 @@ package main
 
 import (
 	"fmt"
-	"log"
 	"os"
 
-	kingpin "gopkg.in/alecthomas/kingpin.v2"
+	"github.com/alecthomas/kong"
 )
 
 // nolint: gochecknoglobals
@@ -16,65 +15,40 @@ var (
 	builtBy = "unknown"
 )
 
-// Config stores the configuration from cli flags and environment variables.
-type appConfig struct {
-	TemplateFile string
-	DataFile     string
-	UseHTML      bool
+// nolint: lll
+type CLI struct {
+	Version      kong.VersionFlag `name:"version" help:"Show version information"`
+	TemplateFile string           `env:"TEMPLE_TEMPLATE_FILE" arg:"" required:"" type:"existingfile" help:"The template file to use"`
+	DataFile     *os.File         `short:"d" name:"data" placeholder:"DATA-FILE" env:"TEMPLE_DATA_FILE" help:"A YAML or JSON file to use via the {{data.<foo>}} interface"`
+	HTML         bool             `short:"H" env:"TEMPLE_USE_HTML" help:"Use HTML templating instead of text templating"`
 }
 
-// NewConfig initializes a Config object from the cli flags and environment variables.
-func main() {
+func (cli *CLI) Run() error {
 	var err error
 
-	config := appConfig{}
-
-	kingpin.CommandLine.Writer(os.Stdout)
-	kingpin.HelpFlag.Short('h')
-	kingpin.CommandLine.Help = "Fast and simple templating engine"
-	kingpin.CommandLine.Author("Christian Höltje")
-	kingpin.Version(
-		fmt.Sprintf("version\t%s\ncommit\t%s\nbuilt\t%s by %s", version, commit, date, builtBy),
-	)
-
-	kingpin.
-		Flag("data", "A YAML or JSON file to use via the {{data.<foo>}} interface (Env: TEMPLE_DATA_FILE)").
-		Short('d').
-		PlaceHolder("DATA-FILE").
-		OverrideDefaultFromEnvar("TEMPLE_DATA_FILE").
-		ExistingFileVar(&config.DataFile)
-
-	kingpin.
-		Flag("html", "Use HTML templating instead of text templating (Env: TEMPLE_HTML)").
-		Short('H').
-		OverrideDefaultFromEnvar("TEMPLE_HTML").
-		BoolVar(&config.UseHTML)
-
-	kingpin.
-		Arg("template", "A Go Template file.").
-		Required().
-		ExistingFileVar(&config.TemplateFile)
-
-	// Handle case where no arguments were presented.
-	if len(os.Args) == 1 {
-		kingpin.Usage()
-		os.Exit(1)
-	}
-
-	kingpin.Parse()
-
-	funcMap, err := buildFuncMap(config.DataFile)
+	funcMap, err := buildFuncMap(cli.DataFile)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
-	if config.UseHTML {
-		err = doHTMLTemplate(config.TemplateFile, funcMap, os.Stdout)
-	} else {
-		err = doTextTemplate(config.TemplateFile, funcMap, os.Stdout)
+	if cli.HTML {
+		return doHTMLTemplate(cli.TemplateFile, funcMap, os.Stdout)
 	}
 
-	if err != nil {
-		log.Fatalln(err)
-	}
+	return doTextTemplate(cli.TemplateFile, funcMap, os.Stdout)
+}
+
+func main() {
+	cli := CLI{}
+
+	ctx := kong.Parse(&cli,
+		kong.Name("temple"),
+		kong.Description("A simple templating engine"),
+		kong.UsageOnError(),
+		kong.Vars{
+			"version": fmt.Sprintf("version\t%s\ncommit\t%s\nbuilt\t%s by %s", version, commit, date, builtBy),
+		},
+	)
+	err := ctx.Run(&cli)
+	ctx.FatalIfErrorf(err)
 }
diff --git a/utils.go b/utils.go
deleted file mode 100644
index c048e6e..0000000
--- a/utils.go
+++ /dev/null
@@ -1,15 +0,0 @@
-package main
-
-import (
-	"log"
-	"os"
-)
-
-func safeOpen(path string) *os.File {
-	file, err := os.Open(path)
-	if err != nil {
-		log.Fatalf("Unable to open %s: %s", path, err)
-	}
-
-	return file
-}