Add a hex wrapper.

Author: scr-oath

hex/README.md

@@ -0,0 +1,54 @@
+# hex [![GoDoc](https://godoc.org/github.com/vadv/gopher-lua-libs/hex?status.svg)](https://godoc.org/github.com/vadv/gopher-lua-libs/hex)
+
+Lua module for [encoding/hex](https://pkg.go.dev/encoding/hex)
+
+## Usage
+
+### Encoding
+
+```lua
+local hex = require("hex")
+
+s = hex.RawStdEncoding:encode_to_string("foo\01bar")
+print(s)
+Zm9vAWJhcg
+
+s = hex.StdEncoding:encode_to_string("foo\01bar")
+print(s)
+Zm9vAWJhcg==
+
+s = hex.RawURLEncoding:encode_to_string("this is a <tag> and should be encoded")
+print(s)
+dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA
+
+s = hex.URLEncoding:encode_to_string("this is a <tag> and should be encoded")
+print(s)
+dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA==
+
+```
+
+### Decoding
+
+```lua
+local hex = require 'hex'
+
+s, err = hex.decode_string("Zm9vAWJhcg")
+assert(not err, err)
+print(s)
+foo
bar
+
+s, err = hex.StdEncoding:decode_string("Zm9vAWJhcg==")
+assert(not err, err)
+print(s)
+foo
bar
+
+s, err = hex.RawURLEncoding:decode_string("dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA")
+assert(not err, err)
+print(s)
+this is a <tag> and should be encoded
+
+s, err = hex.URLEncoding:decode_string("dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA==")
+assert(not err, err)
+print(s)
+this is a <tag> and should be encoded
+```

hex/api.go

@@ -0,0 +1,84 @@
+// Package hex implements base64 encode/decode functionality for lua.
+package hex
+
+import (
+	"encoding/hex"
+	"io"
+
+	lio "github.com/vadv/gopher-lua-libs/io"
+	lua "github.com/yuin/gopher-lua"
+)
+
+const (
+	hexEncoderType = "hex.Encoder"
+	hexDecoderType = "hex.Decoder"
+)
+
+// LVHexEncoder creates a new Lua user data for the hex encoder
+func LVHexEncoder(L *lua.LState, writer io.Writer) lua.LValue {
+	ud := L.NewUserData()
+	ud.Value = writer
+	L.SetMetatable(ud, L.GetTypeMetatable(hexEncoderType))
+	return ud
+}
+
+// LVHexDecoder creates a new Lua user data for the hex decoder
+func LVHexDecoder(L *lua.LState, reader io.Reader) lua.LValue {
+	ud := L.NewUserData()
+	ud.Value = reader
+	L.SetMetatable(ud, L.GetTypeMetatable(hexDecoderType))
+	return ud
+}
+
+// DecodeString decodes the encoded string with the encoding
+func DecodeString(L *lua.LState) int {
+	encoded := L.CheckString(1)
+	L.Pop(L.GetTop())
+	decoded, err := hex.DecodeString(encoded)
+	if err != nil {
+		L.Push(lua.LNil)
+		L.Push(lua.LString(err.Error()))
+		return 2
+	}
+	L.Push(lua.LString(decoded))
+	return 1
+}
+
+// EncodeToString decodes the string with the encoding
+func EncodeToString(L *lua.LState) int {
+	decoded := L.CheckString(1)
+	L.Pop(L.GetTop())
+	encoded := hex.EncodeToString([]byte(decoded))
+	L.Push(lua.LString(encoded))
+	return 1
+}
+
+// registerHexEncoder Registers the encoder type and its methods
+func registerHexEncoder(L *lua.LState) {
+	mt := L.NewTypeMetatable(hexEncoderType)
+	L.SetGlobal(hexEncoderType, mt)
+	L.SetField(mt, "__index", lio.WriterFuncTable(L))
+}
+
+// registerHexDecoder Registers the decoder type and its methods
+func registerHexDecoder(L *lua.LState) {
+	mt := L.NewTypeMetatable(hexDecoderType)
+	L.SetGlobal(hexDecoderType, mt)
+	L.SetField(mt, "__index", lio.ReaderFuncTable(L))
+}
+
+func NewEncoder(L *lua.LState) int {
+	writer := lio.CheckIOWriter(L, 1)
+	L.Pop(L.GetTop())
+	encoder := hex.NewEncoder(writer)
+	L.Push(LVHexEncoder(L, encoder))
+	return 1
+}
+
+func NewDecoder(L *lua.LState) int {
+	reader := lio.CheckIOReader(L, 1)
+	L.Pop(L.GetTop())
+	decoder := hex.NewDecoder(reader)
+	L.Push(LVHexDecoder(L, decoder))
+	return 1
+}

hex/api_test.go

@@ -0,0 +1,14 @@
+package hex
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/vadv/gopher-lua-libs/strings"
+	"github.com/vadv/gopher-lua-libs/tests"
+)
+
+func TestApi(t *testing.T) {
+	preload := tests.SeveralPreloadFuncs(Preload, strings.Preload)
+	assert.NotZero(t, tests.RunLuaTestFile(t, preload, "./test/test_api.lua"))
+}

hex/example_test.go

@@ -0,0 +1,69 @@
+package hex
+
+import (
+	"log"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+func ExampleEncodeToString() {
+	state := lua.NewState()
+	defer state.Close()
+	Preload(state)
+	source := `
+    local base64 = require("base64")
+	s = base64.RawStdEncoding:encode_to_string("foo\01bar")
+	print(s)
+
+	s = base64.StdEncoding:encode_to_string("foo\01bar")
+	print(s)
+
+	s = base64.RawURLEncoding:encode_to_string("this is a <tag> and should be encoded")
+	print(s)
+
+	s = base64.URLEncoding:encode_to_string("this is a <tag> and should be encoded")
+	print(s)
+
+`
+	if err := state.DoString(source); err != nil {
+		log.Fatal(err.Error())
+	}
+	// Output:
+	// Zm9vAWJhcg
+	// Zm9vAWJhcg==
+	// dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA
+	// dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA==
+}
+
+func ExampleDecodeString() {
+	state := lua.NewState()
+	defer state.Close()
+	Preload(state)
+	source := `
+    local base64 = require("base64")
+	s, err = base64.RawStdEncoding:decode_string("Zm9vAWJhcg")
+	assert(not err, err)
+	print(s)
+
+	s, err = base64.StdEncoding:decode_string("Zm9vAWJhcg==")
+	assert(not err, err)
+	print(s)
+
+	s, err = base64.RawURLEncoding:decode_string("dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA")
+	assert(not err, err)
+	print(s)
+
+	s, err = base64.URLEncoding:decode_string("dGhpcyBpcyBhIDx0YWc-IGFuZCBzaG91bGQgYmUgZW5jb2RlZA==")
+	assert(not err, err)
+	print(s)
+
+`
+	if err := state.DoString(source); err != nil {
+		log.Fatal(err.Error())
+	}
+	// Output:
+	// foo
bar
+	// foo
bar
+	// this is a <tag> and should be encoded
+	// this is a <tag> and should be encoded
+}

hex/loader.go

@@ -0,0 +1,30 @@
+package hex
+
+import (
+	lua "github.com/yuin/gopher-lua"
+)
+
+// Preload adds yaml to the given Lua state's package.preload table. After it
+// has been preloaded, it can be loaded using require:
+//
+//	local yaml = require("yaml")
+func Preload(L *lua.LState) {
+	L.PreloadModule("hex", Loader)
+}
+
+// Loader is the module loader function.
+func Loader(L *lua.LState) int {
+	registerHexDecoder(L)
+	registerHexEncoder(L)
+
+	// Register the encodings offered by base64 go module.
+	t := L.NewTable()
+	L.SetFuncs(t, map[string]lua.LGFunction{
+		"decode_string":    DecodeString,
+		"encode_to_string": EncodeToString,
+		"new_encoder":      NewEncoder,
+		"new_decoder":      NewDecoder,
+	})
+	L.Push(t)
+	return 1
+}

hex/test/test_api.lua

@@ -0,0 +1,43 @@
+local hex = require 'hex'
+local strings = require 'strings'
+local assert = require 'assert'
+
+function TestHexCodec(t)
+    local tests = {
+        {
+            encoded = "48656c6c6f20776f726c64", -- "Hello world" in hex
+            decoded = "Hello world",
+        },
+        {
+            encoded = "",
+            decoded = "",
+        },
+    }
+    for _, tt in ipairs(tests) do
+        t:Run("hex.decode_string(" .. tostring(tt.encoded) .. ")", function(t)
+            local got = hex.decode_string(tt.encoded)
+            assert:Equal(t, tt.decoded, got)
+        end)
+
+        t:Run("hex.encode_to_string(" .. tostring(tt.decoded) .. ")", function(t)
+            local got = hex.encode_to_string(tt.decoded)
+            assert:Equal(t, tt.encoded, got)
+        end)
+    end
+end
+
+function TestEncoder(t)
+    local writer = strings.new_builder()
+    local encoder = hex.new_encoder(writer)
+    encoder:write("foo", "bar", "baz")
+    encoder:close()
+    local s = writer:string()
+    assert:Equal(t, "666f6f62617262617a", s)
+end
+
+function TestDecoder(t)
+    local reader = strings.new_reader("666f6f62617262617a")
+    local decoder = hex.new_decoder(reader)
+    local s = decoder:read("*a")
+    assert:Equal(t, "foobarbaz", s)
+end

plugin/preload.go

@@ -12,6 +12,7 @@ import (
 	"github.com/vadv/gopher-lua-libs/db"
 	"github.com/vadv/gopher-lua-libs/filepath"
 	"github.com/vadv/gopher-lua-libs/goos"
+	"github.com/vadv/gopher-lua-libs/hex"
 	"github.com/vadv/gopher-lua-libs/http"
 	"github.com/vadv/gopher-lua-libs/humanize"
 	"github.com/vadv/gopher-lua-libs/inspect"
@@ -44,6 +45,7 @@ func PreloadAll(L *lua.LState) {
 
 	argparse.Preload(L)
 	base64.Preload(L)
+	bit.Preload(L)
 	cert_util.Preload(L)
 	chef.Preload(L)
 	cloudwatch.Preload(L)
@@ -52,6 +54,7 @@ func PreloadAll(L *lua.LState) {
 	db.Preload(L)
 	filepath.Preload(L)
 	goos.Preload(L)
+	hex.Preload(L)
 	http.Preload(L)
 	humanize.Preload(L)
 	inspect.Preload(L)
@@ -75,5 +78,4 @@ func PreloadAll(L *lua.LState) {
 	xmlpath.Preload(L)
 	yaml.Preload(L)
 	zabbix.Preload(L)
-	bit.Preload(L)
 }