tpl/math: Make it a package that stands on its own

See #3042

4 files changed, 102 insertions, 22 deletions

diff --git a/tpl/math/init.go b/tpl/math/init.go
new file mode 100644
index 000000000..69ba2cc17
--- /dev/null
+++ b/tpl/math/init.go
@@ -0,0 +1,53 @@
+// Copyright 2017 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package math
+
+import (
+	"github.com/spf13/hugo/deps"
+	"github.com/spf13/hugo/tpl/internal"
+)
+
+const name = "math"
+
+func init() {
+	f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
+		ctx := New()
+
+		examples := [][2]string{
+			{"{{add 1 2}}", "3"},
+			{"{{div 6 3}}", "2"},
+			{"{{mod 15 3}}", "0"},
+			{"{{modBool 15 3}}", "true"},
+			{"{{mul 2 3}}", "6"},
+			{"{{sub 3 2}}", "1"},
+		}
+
+		return &internal.TemplateFuncsNamespace{
+			Name:    name,
+			Context: func() interface{} { return ctx },
+			Aliases: map[string]interface{}{
+				"add":     ctx.Add,
+				"div":     ctx.Div,
+				"mod":     ctx.Mod,
+				"modBool": ctx.ModBool,
+				"mul":     ctx.Mul,
+				"sub":     ctx.Sub,
+			},
+			Examples: examples,
+		}
+
+	}
+
+	internal.AddTemplateFuncsNamespace(f)
+}
diff --git a/tpl/tplimpl/templateFuncster.go b/tpl/tplimpl/templateFuncster.go
index c8afec51a..e533e0db8 100644
--- a/tpl/tplimpl/templateFuncster.go
+++ b/tpl/tplimpl/templateFuncster.go
@@ -27,7 +27,6 @@ import (
 	"github.com/spf13/hugo/tpl/encoding"
 	"github.com/spf13/hugo/tpl/images"
 	"github.com/spf13/hugo/tpl/inflect"
-	"github.com/spf13/hugo/tpl/math"
 	"github.com/spf13/hugo/tpl/os"
 	"github.com/spf13/hugo/tpl/safe"
 	hstrings "github.com/spf13/hugo/tpl/strings"
@@ -48,7 +47,6 @@ type templateFuncster struct {
 	encoding    *encoding.Namespace
 	images      *images.Namespace
 	inflect     *inflect.Namespace
-	math        *math.Namespace
 	os          *os.Namespace
 	safe        *safe.Namespace
 	strings     *hstrings.Namespace
@@ -71,7 +69,6 @@ func newTemplateFuncster(deps *deps.Deps) *templateFuncster {
 		encoding:    encoding.New(),
 		images:      images.New(deps),
 		inflect:     inflect.New(),
-		math:        math.New(),
 		os:          os.New(deps),
 		safe:        safe.New(),
 		strings:     hstrings.New(deps),
diff --git a/tpl/tplimpl/template_funcs.go b/tpl/tplimpl/template_funcs.go
index b1d7d71f9..d29bbbd06 100644
--- a/tpl/tplimpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -26,6 +26,7 @@ import (
 
 	// Init the namespaces
 	_ "github.com/spf13/hugo/tpl/lang"
+	_ "github.com/spf13/hugo/tpl/math"
 )
 
 // Get retrieves partial output from the cache based upon the partial name.
@@ -84,7 +85,6 @@ func (t *templateFuncster) initFuncMap() {
 		"encoding":    t.encoding.Namespace,
 		"images":      t.images.Namespace,
 		"inflect":     t.inflect.Namespace,
-		"math":        t.math.Namespace,
 		"os":          t.os.Namespace,
 		"safe":        t.safe.Namespace,
 		"strings":     t.strings.Namespace,
@@ -94,7 +94,6 @@ func (t *templateFuncster) initFuncMap() {
 
 		"absURL":        t.urls.AbsURL,
 		"absLangURL":    t.urls.AbsLangURL,
-		"add":           t.math.Add,
 		"after":         t.collections.After,
 		"apply":         t.collections.Apply,
 		"base64Decode":  t.encoding.Base64Decode,
@@ -106,7 +105,6 @@ func (t *templateFuncster) initFuncMap() {
 		"dateFormat":    t.time.Format,
 		"delimit":       t.collections.Delimit,
 		"dict":          t.collections.Dictionary,
-		"div":           t.math.Div,
 		"echoParam":     t.collections.EchoParam,
 		"emojify":       t.transform.Emojify,
 		"eq":            compare.Eq,
@@ -136,9 +134,6 @@ func (t *templateFuncster) initFuncMap() {
 		"lt":            compare.Lt,
 		"markdownify":   t.transform.Markdownify,
 		"md5":           t.crypto.MD5,
-		"mod":           t.math.Mod,
-		"modBool":       t.math.ModBool,
-		"mul":           t.math.Mul,
 		"ne":            compare.Ne,
 		"now":           t.time.Now,
 		"partial":       t.partial,
@@ -175,7 +170,6 @@ func (t *templateFuncster) initFuncMap() {
 		"sort":          t.collections.Sort,
 		"split":         t.strings.Split,
 		"string":        func(v interface{}) (string, error) { return cast.ToStringE(v) },
-		"sub":           t.math.Sub,
 		"substr":        t.strings.Substr,
 		"time":          t.time.AsTime,
 		"title":         t.strings.Title,
diff --git a/tpl/tplimpl/template_funcs_test.go b/tpl/tplimpl/template_funcs_test.go
index bdbe067c9..ba9c1b77c 100644
--- a/tpl/tplimpl/template_funcs_test.go
+++ b/tpl/tplimpl/template_funcs_test.go
@@ -32,6 +32,7 @@ import (
 	"github.com/spf13/hugo/hugofs"
 	"github.com/spf13/hugo/i18n"
 	"github.com/spf13/hugo/tpl"
+	"github.com/spf13/hugo/tpl/internal"
 	jww "github.com/spf13/jwalterweatherman"
 	"github.com/spf13/viper"
 	"github.com/stretchr/testify/require"
@@ -54,6 +55,53 @@ func newDepsConfig(cfg config.Provider) deps.DepsCfg {
 	}
 }
 
+func TestTemplateFuncsExamples(t *testing.T) {
+	t.Parallel()
+
+	workingDir := "/home/hugo"
+
+	v := viper.New()
+
+	v.Set("workingDir", workingDir)
+	v.Set("multilingual", true)
+
+	fs := hugofs.NewMem(v)
+
+	afero.WriteFile(fs.Source, filepath.Join(workingDir, "README.txt"), []byte("Hugo Rocks!"), 0755)
+
+	d, err := deps.New(newDepsConfig(v))
+	require.NoError(t, err)
+
+	var data struct {
+		Title   string
+		Section string
+		Params  map[string]interface{}
+	}
+
+	data.Title = "**BatMan**"
+	data.Section = "blog"
+	data.Params = map[string]interface{}{"langCode": "en"}
+
+	for _, nsf := range internal.TemplateFuncsNamespaceRegistry {
+		ns := nsf(d)
+		for i, example := range ns.Examples {
+			in, expected := example[0], example[1]
+			d.WithTemplate = func(templ tpl.TemplateHandler) error {
+				require.NoError(t, templ.AddTemplate("test", in))
+				return nil
+			}
+			require.NoError(t, d.LoadResources())
+
+			var b bytes.Buffer
+			require.NoError(t, d.Tmpl.Lookup("test").Execute(&b, &data))
+			if b.String() != expected {
+				t.Fatalf("%s[%d]: got %q expected %q", ns.Name, i, b.String(), expected)
+			}
+		}
+	}
+
+}
+
 func TestFuncsInTemplate(t *testing.T) {
 	t.Parallel()
 
@@ -76,7 +124,6 @@ func TestFuncsInTemplate(t *testing.T) {
 absURL: {{ "http://gohugo.io/" | absURL }}
 absURL: {{ "mystyle.css" | absURL }}
 absURL: {{ 42 | absURL }}
-add: {{add 1 2}}
 base64Decode 1: {{ "SGVsbG8gd29ybGQ=" | base64Decode }}
 base64Decode 2: {{ 42 | base64Encode | base64Decode }}
 base64Encode: {{ "Hello world" | base64Encode }}
@@ -84,7 +131,6 @@ chomp: {{chomp "<p>Blockhead</p>\n" }}
 crypto.MD5: {{ crypto.MD5 "Hello world, gophers!" }}
 dateFormat: {{ dateFormat "Monday, Jan 2, 2006" "2015-01-21" }}
 delimit: {{ delimit (slice "A" "B" "C") ", " " and " }}
-div: {{div 6 3}}
 echoParam: {{ echoParam .Params "langCode" }}
 emojify: {{ "I :heart: Hugo" | emojify }}
 eq: {{ if eq .Section "blog" }}current{{ end }}
@@ -107,9 +153,6 @@ jsonify: {{ (slice "A" "B" "C") | jsonify }}
 lower: {{lower "BatMan"}}
 markdownify: {{ .Title | markdownify}}
 md5: {{ md5 "Hello world, gophers!" }}
-mod: {{mod 15 3}}
-modBool: {{modBool 15 3}}
-mul: {{mul 2 3}}
 print: {{ print "works!" }}
 printf: {{ printf "%s!" "works" }}
 println: {{ println "works!" -}}
@@ -138,7 +181,6 @@ slicestr: {{slicestr "BatMan" 0 3}}
 slicestr: {{slicestr "BatMan" 3}}
 sort: {{ slice "B" "C" "A" | sort }}
 strings.TrimPrefix: {{ strings.TrimPrefix "Goodbye,, world!" "Goodbye," }}
-sub: {{sub 3 2}}
 substr: {{substr "BatMan" 0 -3}}
 substr: {{substr "BatMan" 3 3}}
 title: {{title "Bat man"}}
@@ -155,7 +197,6 @@ urlize: {{ "Bat Man" | urlize }}
 absURL: http://gohugo.io/
 absURL: http://mysite.com/hugo/mystyle.css
 absURL: http://mysite.com/hugo/42
-add: 3
 base64Decode 1: Hello world
 base64Decode 2: 42
 base64Encode: SGVsbG8gd29ybGQ=
@@ -163,7 +204,6 @@ chomp: <p>Blockhead</p>
 crypto.MD5: b3029f756f98f79e7f1b7f1d1f0dd53b
 dateFormat: Wednesday, Jan 21, 2015
 delimit: A, B and C
-div: 2
 echoParam: en
 emojify: I ❤️ Hugo
 eq: current
@@ -186,9 +226,6 @@ jsonify: ["A","B","C"]
 lower: batman
 markdownify: <strong>BatMan</strong>
 md5: b3029f756f98f79e7f1b7f1d1f0dd53b
-mod: 0
-modBool: true
-mul: 6
 print: works!
 printf: works!
 println: works!
@@ -217,7 +254,6 @@ slicestr: Bat
 slicestr: Man
 sort: [A B C]
 strings.TrimPrefix: , world!
-sub: 1
 substr: Bat
 substr: Man
 title: Bat Man