adding random generators - close #234

v2/pkg/generators/dsl.go

@@ -7,13 +7,18 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"html"
+	"math"
+	"math/rand"
 	"net/url"
 	"regexp"
 	"strings"
 
 	"github.com/Knetic/govaluate"
 )
 
+var letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+var numbers = "1234567890"
+
 // HelperFunctions contains the dsl functions
 func HelperFunctions() (functions map[string]govaluate.ExpressionFunction) {
 	functions = make(map[string]govaluate.ExpressionFunction)
@@ -144,5 +149,106 @@ func HelperFunctions() (functions map[string]govaluate.ExpressionFunction) {
 		return compiled.MatchString(args[1].(string)), nil
 	}
 
+	// random generators
+	functions["rand_char"] = func(args ...interface{}) (interface{}, error) {
+		chars := letters + numbers
+		bad := ""
+		if len(args) >= 1 {
+			chars = args[0].(string)
+		}
+		if len(args) >= 2 {
+			bad = args[1].(string)
+		}
+
+		chars = TrimAll(chars, bad)
+
+		return chars[rand.Intn(len(chars))], nil
+	}
+
+	functions["rand_base"] = func(args ...interface{}) (interface{}, error) {
+		l := 0
+		bad := ""
+		base := letters + numbers
+
+		if len(args) >= 1 {
+			l = args[0].(int)
+		}
+		if len(args) >= 2 {
+			bad = args[1].(string)
+		}
+		if len(args) >= 3 {
+			base = args[2].(string)
+		}
+
+		base = TrimAll(base, bad)
+
+		return RandSeq(base, l), nil
+	}
+
+	functions["rand_text_alphanumeric"] = func(args ...interface{}) (interface{}, error) {
+		l := 0
+		bad := ""
+		chars := letters + numbers
+
+		if len(args) >= 1 {
+			l = args[0].(int)
+		}
+		if len(args) >= 2 {
+			bad = args[1].(string)
+		}
+
+		chars = TrimAll(chars, bad)
+
+		return RandSeq(chars, l), nil
+	}
+
+	functions["rand_text_alpha"] = func(args ...interface{}) (interface{}, error) {
+		l := 0
+		bad := ""
+		chars := letters
+
+		if len(args) >= 1 {
+			l = args[0].(int)
+		}
+		if len(args) >= 2 {
+			bad = args[1].(string)
+		}
+
+		chars = TrimAll(chars, bad)
+
+		return RandSeq(chars, l), nil
+	}
+
+	functions["rand_text_numeric"] = func(args ...interface{}) (interface{}, error) {
+		l := 0
+		bad := ""
+		chars := numbers
+
+		if len(args) >= 1 {
+			l = args[0].(int)
+		}
+		if len(args) >= 2 {
+			bad = args[1].(string)
+		}
+
+		chars = TrimAll(chars, bad)
+
+		return RandSeq(chars, l), nil
+	}
+
+	functions["rand_int"] = func(args ...interface{}) (interface{}, error) {
+		min := 0
+		max := math.MaxInt32
+
+		if len(args) >= 1 {
+			min = args[0].(int)
+		}
+		if len(args) >= 2 {
+			max = args[1].(int)
+		}
+
+		return rand.Intn(max-min) + min, nil
+	}
+
 	return functions
 }

v2/pkg/generators/util.go

@@ -3,6 +3,7 @@ package generators
 import (
 	"bufio"
 	"fmt"
+	"math/rand"
 	"os"
 	"strings"
 )
@@ -158,3 +159,28 @@ func FileExists(filename string) bool {
 
 	return !info.IsDir()
 }
+
+// TrimDelimiters removes trailing brackets
+func SliceContins(s []string, k string) bool {
+	for _, a := range s {
+		if a == k {
+			return true
+		}
+	}
+	return false
+}
+
+func TrimAll(s string, cutset string) string {
+	for _, c := range cutset {
+		s = strings.ReplaceAll(s, string(c), "")
+	}
+	return s
+}
+
+func RandSeq(base string, n int) string {
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = rune(base[rand.Intn(len(base))])
+	}
+	return string(b)
+}