From 2ad9a2cdaee0124d93387a5820ae0422d19ca3ec Mon Sep 17 00:00:00 2001
From: kozmod <gizmod@bk.ru>
Date: Thu, 16 Feb 2023 15:37:22 +0300
Subject: [PATCH] [#61] add `{{ random.ASCII 8 }}` for templates

---
 Readme.md                      | 12 +++++++-----
 internal/entity/entity.go      |  1 +
 internal/entity/entity_test.go | 11 +++++++++++
 internal/entity/rand.go        | 24 ++++++++++++++++++++++++
 4 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/Readme.md b/Readme.md
index 3f25768..6f4dfb7 100644
--- a/Readme.md
+++ b/Readme.md
@@ -360,10 +360,11 @@ dirs:
 
 #### Custom template functions
 
-| Function          |     args     | Description                                                                   |
-|:------------------|:------------:|:------------------------------------------------------------------------------|
-| `random.Alpha`    | length `int` | Generates a random alphabetical `(A-Z, a-z)` string of a desired length.      | 
-| `random.AlphaNum` | length `int` | Generates a random alphanumeric `(0-9, A-Z, a-z)` string of a desired length. |
+| Function          |     args     | Description                                                                                                                                                                       |
+|:------------------|:------------:|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `random.Alpha`    | length `int` | Generates a random alphabetical `(A-Z, a-z)` string of a desired length.                                                                                                          | 
+| `random.AlphaNum` | length `int` | Generates a random alphanumeric `(0-9, A-Z, a-z)` string of a desired length.                                                                                                     |
+| `random.ASCII`    | length `int` | Generates a random string of a desired length, containing the set of printable characters from the 7-bit ASCII set. This includes space (’ ‘), but no other whitespace character. |
 
 Custom template functions adds the elements of the argument map to the
 template's [function map]](https://pkg.go.dev/text/template#hdr-Functions).
@@ -495,6 +496,7 @@ out:
 
 2 directories, 6 files
 ```
+
 `cmd` action maintains "short" declaration syntax
 
 ```yaml
@@ -504,6 +506,7 @@ cmd:
   - pwd
   - ls -a
 ```
+
 ```console
 % progen -v -dr
 2023-02-15 17:56:58	INFO	application working directory: /Users/user_1/GoProjects/progen
@@ -512,7 +515,6 @@ cmd:
 2023-02-15 17:56:58	INFO	execute [dir: .]: ls -a
 ```
 
-
 #### <a name="cmd_pipe"></a> 'Pipe mode'
 
 The `cmd.pipe` option set "pipe mode" for `cmd.exec` section:
diff --git a/internal/entity/entity.go b/internal/entity/entity.go
index f181ac7..b310202 100644
--- a/internal/entity/entity.go
+++ b/internal/entity/entity.go
@@ -39,6 +39,7 @@ const (
 	EqualsSign = "="
 	LessThan   = "<"
 	SpacedPipe = " | "
+	Tilda      = "~"
 
 	NewLine = '\n'
 )
diff --git a/internal/entity/entity_test.go b/internal/entity/entity_test.go
index 33a6694..056b095 100644
--- a/internal/entity/entity_test.go
+++ b/internal/entity/entity_test.go
@@ -84,6 +84,17 @@ func Test_RandomFn(t *testing.T) {
 			assert.Regexp(t, "^[[:alnum:]]*$", s)
 		})
 	})
+	t.Run("ASCII", func(t *testing.T) {
+		t.Run("generate_zero", func(t *testing.T) {
+			s := f.ASCII(0)
+			assert.Empty(t, s)
+		})
+		t.Run("generate_50", func(t *testing.T) {
+			s := f.ASCII(50)
+			assert.Len(t, s, 50)
+			assert.Regexp(t, "^[[:print:]]*$", s)
+		})
+	})
 }
 
 func Test_MissingKye(t *testing.T) {
diff --git a/internal/entity/rand.go b/internal/entity/rand.go
index 614deb0..e3ec1c5 100644
--- a/internal/entity/rand.go
+++ b/internal/entity/rand.go
@@ -3,6 +3,7 @@ package entity
 import (
 	"hash/maphash"
 	"math/rand"
+	"unicode"
 )
 
 // Default set, matches "[a-zA-Z0-9_.-]"
@@ -16,6 +17,8 @@ const (
 )
 
 var (
+	_lettersASCII string
+
 	mapHashSrc = rand.New(rand.NewSource(int64(new(maphash.Hash).Sum64())))
 
 	TemplateFnsMap = map[string]any{
@@ -23,6 +26,21 @@ var (
 	}
 )
 
+func init() {
+	var (
+		lower = int32(Space[0])
+		upper = int32(Tilda[0])
+	)
+
+	chars := make([]rune, 0, int(upper)-int(lower))
+	for r := lower; r <= upper; r++ {
+		if unicode.IsGraphic(r) {
+			chars = append(chars, r)
+		}
+	}
+	_lettersASCII = string(chars)
+}
+
 // RandomFn has to generate random string value
 type RandomFn struct{}
 
@@ -36,6 +54,12 @@ func (RandomFn) AlphaNum(n int) string {
 	return randomString(n, _lettersAlphaNum)
 }
 
+// ASCII Generates a random string of a desired length, containing the set of printable characters from the 7-bit ASCII set.
+// This includes space (’ ‘), but no other whitespace character
+func (RandomFn) ASCII(n int) string {
+	return randomString(n, _lettersASCII)
+}
+
 func randomString(n int, set string) string {
 	src := mapHashSrc
 	b := make([]byte, n)