initial commit

.github/workflows/main.yaml

@@ -0,0 +1,64 @@
+name: Go
+
+on:
+  push:
+    branches: ["master"]
+  pull_request:
+    branches: ["master"]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: "stable"
+
+      - name: Build
+        run: go build -v ./...
+
+  build-readme:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: "stable"
+
+      - name: Build go snippets in readme
+        run: |
+          mkdir -p ~/.local/bin/
+          wget -O ~/.local/bin/lintdown.sh https://raw.githubusercontent.com/ChillerDragon/lintdown.sh/master/lintdown.sh
+          chmod +x ~/.local/bin/lintdown.sh
+          lintdown.sh README.md
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: "stable"
+
+      - name: Test
+        run: go test -v -race -count=1 ./...
+
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: "stable"
+
+      - name: Format
+        run: diff -u <(echo -n) <(gofmt -d ./)

LICENSE

@@ -0,0 +1,7 @@
+Copyright 2024 John Behm
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -0,0 +1,40 @@
+# varint
+
+varint is a simple variable-length integer encoding. It is a way to store integers in a space-efficient manner.
+This variant of varint is space efficient for small integers and is used in the Teeworlds network protocol.
+
+Additionally this linrary also provides functions that operate on 64bit integers which is out of scope of the Teeeworlds protocol.
+These varants may be used for security research or other purposes.
+
+```text
+/ Format: ESDDDDDD EDDDDDDD EDD... Extended, Sign, Data,
+// E: is next byte part of the current integer
+// S: Sign of integer 0 = positive, 1 = negative
+// Data, Integer bits that follow the sign
+```
+
+## Example
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"github.com/teeworlds-go/varint"
+)
+
+func main() {
+	buf := make([]byte, varint.MaxVarintLen32)
+	written := varint.PutVarint(buf, 33)
+	out, read := varint.Varint(buf)
+	fmt.Println("written:", written)
+	fmt.Println("read:", read)
+	fmt.Println("value:", out)
+	// Output:
+	// written: 1
+	// read: 1
+	// value: 33
+}
+```
+

go.mod

@@ -0,0 +1,3 @@
+module github.com/teeworlds-go/varint
+
+go 1.22.5

internal/testutils/require/compare.go

@@ -0,0 +1,108 @@
+package require
+
+import (
+	"cmp"
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func GreaterOrEqual(t *testing.T, expected, actual any, msgAndArgs ...any) {
+	t.Helper()
+
+	if compare(t, actual, expected) < 0 {
+		FailNow(t, fmt.Sprintf("expected actual value: %v to be greater or equal to: %v", actual, expected), msgAndArgs...)
+	}
+}
+
+func Greater(t *testing.T, expected, actual any, msgAndArgs ...any) {
+	t.Helper()
+
+	if compare(t, actual, expected) <= 0 {
+		FailNow(t, fmt.Sprintf("expected actual value: %v to be greater than: %v", actual, expected), msgAndArgs...)
+	}
+}
+
+func LessOrEqual(t *testing.T, expected, actual any, msgAndArgs ...any) {
+	t.Helper()
+
+	if compare(t, actual, expected) > 0 {
+		FailNow(t, fmt.Sprintf("expected actual value: %v to be less or equal to: %v", actual, expected), msgAndArgs...)
+	}
+}
+
+func Less(t *testing.T, expected, actual any, msgAndArgs ...any) {
+	t.Helper()
+
+	if compare(t, actual, expected) >= 0 {
+		FailNow(t, fmt.Sprintf("expected actual value: %v to be less than: %v", actual, expected), msgAndArgs...)
+	}
+}
+
+// compare returns
+//
+// -1 if expected is less than actual,
+//
+//	0 if expected equals actual,
+//
+// +1 if expected is greater than actual.
+func compare(t *testing.T, expected, actual any) int {
+	t.Helper()
+
+	e := reflect.ValueOf(expected)
+	a := reflect.ValueOf(actual)
+
+	if e.Kind() != a.Kind() {
+		FailNow(t, "type mismatch: expected %T, got %T", expected, actual)
+	}
+
+	if !e.Comparable() {
+		FailNow(t, "expected value is not comparable")
+	}
+
+	if !a.Comparable() {
+		FailNow(t, "actual value is not comparable")
+	}
+
+	if e.Kind() != a.Kind() {
+		FailNow(t, "type mismatch: expected %T, got %T", expected, actual)
+	}
+
+	switch e.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		{
+			ev := e.Convert(reflect.TypeOf(int64(0))).Interface().(int64)
+			av := a.Convert(reflect.TypeOf(int64(0))).Interface().(int64)
+			return cmp.Compare(ev, av)
+		}
+
+	case reflect.Uint8, reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		{
+			ev := e.Convert(reflect.TypeOf(uint64(0))).Interface().(uint64)
+			av := a.Convert(reflect.TypeOf(uint64(0))).Interface().(uint64)
+			return cmp.Compare(ev, av)
+		}
+
+	case reflect.Float32, reflect.Float64:
+		{
+			ev := e.Convert(reflect.TypeOf(float64(0))).Interface().(float64)
+			av := a.Convert(reflect.TypeOf(float64(0))).Interface().(float64)
+			return cmp.Compare(ev, av)
+		}
+	case reflect.String:
+		{
+			ev := e.Convert(reflect.TypeOf(string(""))).Interface().(string)
+			av := a.Convert(reflect.TypeOf(string(""))).Interface().(string)
+			return cmp.Compare(ev, av)
+		}
+	case reflect.Uintptr:
+		{
+			ev := e.Convert(reflect.TypeOf(uintptr(0))).Interface().(uintptr)
+			av := a.Convert(reflect.TypeOf(uintptr(0))).Interface().(uintptr)
+			return cmp.Compare(ev, av)
+		}
+	}
+
+	FailNow(t, "type not supported: %T", expected)
+	return 0 // should not be reached
+}

internal/testutils/require/compare_test.go

@@ -0,0 +1,20 @@
+package require
+
+import "testing"
+
+func TestCompare(t *testing.T) {
+	GreaterOrEqual(t, 1, 2)
+	GreaterOrEqual(t, 1, 1)
+	Greater(t, 1, 2)
+	LessOrEqual(t, 2, 1)
+	LessOrEqual(t, 1, 1)
+	Less(t, 2, 1)
+
+	require := New(t)
+	require.GreaterOrEqual(1, 2)
+	require.GreaterOrEqual(1, 1)
+	require.Greater(1, 2)
+	require.LessOrEqual(2, 1)
+	require.LessOrEqual(1, 1)
+	require.Less(2, 1)
+}

internal/testutils/require/fail.go

@@ -0,0 +1,31 @@
+package require
+
+import (
+	"strings"
+	"testing"
+)
+
+func FailNow(t *testing.T, errMsg string, msgAndArgs ...any) {
+	t.Helper()
+
+	labeledMessages := labeledMessages{
+		{
+			label:   "Error Trace",
+			message: strings.Join(CallStack(), "\n\t\t\t"),
+		},
+		{
+			label:   "Error",
+			message: errMsg,
+		},
+	}
+
+	message := msgOrFmtMsg(msgAndArgs...)
+	if len(message) > 0 {
+		labeledMessages = append(labeledMessages, labeledMessage{
+			label:   "Message",
+			message: message,
+		})
+	}
+
+	t.Fatal(labeledMessages.String())
+}

internal/testutils/require/format.go

@@ -0,0 +1,71 @@
+package require
+
+import (
+	"bufio"
+	"fmt"
+	"strings"
+)
+
+func msgOrFmtMsg(msgAndArgs ...any) string {
+	if len(msgAndArgs) == 0 || msgAndArgs == nil {
+		return ""
+	}
+	if len(msgAndArgs) == 1 {
+		msg := msgAndArgs[0]
+		if msgAsStr, ok := msg.(string); ok {
+			return msgAsStr
+		}
+		return fmt.Sprintf("%+v", msg)
+	}
+	if len(msgAndArgs) > 1 {
+		return fmt.Sprintf(msgAndArgs[0].(string), msgAndArgs[1:]...)
+	}
+	return ""
+}
+
+type labeledMessage struct {
+	label   string
+	message string
+}
+
+type labeledMessages []labeledMessage
+
+func (lm labeledMessages) String() string {
+	longestLabel := 0
+	numLabels := len(lm)
+	msgSizeTotal := 0
+	for _, v := range lm {
+		if len(v.label) > longestLabel {
+			longestLabel = len(v.label)
+		}
+		msgSizeTotal += len(v.message)
+	}
+
+	var sb strings.Builder
+	sb.Grow(msgSizeTotal + numLabels*(longestLabel+8))
+	sb.WriteString("\n")
+
+	for _, v := range lm {
+		sb.WriteString("\t")
+		sb.WriteString(v.label)
+		sb.WriteString(":")
+		sb.WriteString(strings.Repeat(" ", longestLabel-len(v.label)))
+		sb.WriteString("\t")
+
+		// indent lines
+		for i, scanner := 0, bufio.NewScanner(strings.NewReader(v.message)); scanner.Scan(); i++ {
+			// no need to align first line because it starts at the correct location (after the label)
+			if i != 0 {
+				// append alignLen+1 spaces to align with "{{longestLabel}}:" before adding tab
+				sb.WriteString("\n\t")
+				sb.WriteString(strings.Repeat(" ", longestLabel+1))
+				sb.WriteString("\t")
+			}
+			// write line
+			sb.WriteString(scanner.Text())
+		}
+		sb.WriteString("\n")
+	}
+
+	return sb.String()
+}