Merge template functions "dict/Dict/mergeinto" (#23932)

One of the steps in #23328


Before there were 3 different but similar functions: dict/Dict/mergeinto

The code was just copied & pasted, no test.

This PR defines a new stable `dict` function, it covers all the 3 old
functions behaviors, only +160 -171


Future developers do not need to think about or guess the different dict
functions, just use one: `dict`

Why use `dict` but not `Dict`? Because there are far more `dict` than
`Dict` in code already ......

modules/templates/helper.go

@@ -8,7 +8,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"html"
 	"html/template"
@@ -219,20 +218,6 @@ func NewFuncMap() []template.FuncMap {
 		"DisableImportLocal": func() bool {
 			return !setting.ImportLocalPaths
 		},
-		"Dict": func(values ...interface{}) (map[string]interface{}, error) {
-			if len(values)%2 != 0 {
-				return nil, errors.New("invalid dict call")
-			}
-			dict := make(map[string]interface{}, len(values)/2)
-			for i := 0; i < len(values); i += 2 {
-				key, ok := values[i].(string)
-				if !ok {
-					return nil, errors.New("dict keys must be strings")
-				}
-				dict[key] = values[i+1]
-			}
-			return dict, nil
-		},
 		"Printf":   fmt.Sprintf,
 		"Escape":   Escape,
 		"Sec2Time": util.SecToTime,
@@ -242,35 +227,7 @@ func NewFuncMap() []template.FuncMap {
 		"DefaultTheme": func() string {
 			return setting.UI.DefaultTheme
 		},
-		// pass key-value pairs to a partial template which receives them as a dict
-		"dict": func(values ...interface{}) (map[string]interface{}, error) {
-			if len(values) == 0 {
-				return nil, errors.New("invalid dict call")
-			}
-
-			dict := make(map[string]interface{})
-			return util.MergeInto(dict, values...)
-		},
-		/* like dict but merge key-value pairs into the first dict and return it */
-		"mergeinto": func(root map[string]interface{}, values ...interface{}) (map[string]interface{}, error) {
-			if len(values) == 0 {
-				return nil, errors.New("invalid mergeinto call")
-			}
-
-			dict := make(map[string]interface{})
-			for key, value := range root {
-				dict[key] = value
-			}
-
-			return util.MergeInto(dict, values...)
-		},
-		"percentage": func(n int, values ...int) float32 {
-			sum := 0
-			for i := 0; i < len(values); i++ {
-				sum += values[i]
-			}
-			return float32(n) * 100 / float32(sum)
-		},
+		"dict":                dict,
 		"CommentMustAsDiff":   gitdiff.CommentMustAsDiff,
 		"MirrorRemoteAddress": mirrorRemoteAddress,
 		"NotificationSettings": func() map[string]interface{} {
@@ -413,52 +370,13 @@ func NewTextFuncMap() []texttmpl.FuncMap {
 		},
 		"EllipsisString": base.EllipsisString,
 		"URLJoin":        util.URLJoin,
-		"Dict": func(values ...interface{}) (map[string]interface{}, error) {
-			if len(values)%2 != 0 {
-				return nil, errors.New("invalid dict call")
-			}
-			dict := make(map[string]interface{}, len(values)/2)
-			for i := 0; i < len(values); i += 2 {
-				key, ok := values[i].(string)
-				if !ok {
-					return nil, errors.New("dict keys must be strings")
-				}
-				dict[key] = values[i+1]
-			}
-			return dict, nil
-		},
-		"Printf":   fmt.Sprintf,
-		"Escape":   Escape,
-		"Sec2Time": util.SecToTime,
+		"Printf":         fmt.Sprintf,
+		"Escape":         Escape,
+		"Sec2Time":       util.SecToTime,
 		"ParseDeadline": func(deadline string) []string {
 			return strings.Split(deadline, "|")
 		},
-		"dict": func(values ...interface{}) (map[string]interface{}, error) {
-			if len(values) == 0 {
-				return nil, errors.New("invalid dict call")
-			}
-
-			dict := make(map[string]interface{})
-
-			for i := 0; i < len(values); i++ {
-				switch key := values[i].(type) {
-				case string:
-					i++
-					if i == len(values) {
-						return nil, errors.New("specify the key for non array values")
-					}
-					dict[key] = values[i]
-				case map[string]interface{}:
-					m := values[i].(map[string]interface{})
-					for i, v := range m {
-						dict[i] = v
-					}
-				default:
-					return nil, errors.New("dict values must be maps")
-				}
-			}
-			return dict, nil
-		},
+		"dict":        dict,
 		"QueryEscape": url.QueryEscape,
 		"Eval":        Eval,
 	}}