Add validation package (#19)

Closes #7

Added a simple validation package we can expand on. For now we can use it to validate links that get sent to the bot and make sure that:
1. It's an actual url
2. It's a url for a service we support

Also added a make file to run tests and other tasks we might need in the future.

Added a github action to run tests.

Reviewed-on: #19
Co-authored-by: Javier Feliz <me@javierfeliz.com>
Co-committed-by: Javier Feliz <me@javierfeliz.com>

.gitea/workflows/tests.yml

@@ -0,0 +1,21 @@
+name: Run Go Tests
+
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    name: Run Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: '1.22'
+
+      - name: Run Tests
+        run: make test

Makefile

@@ -0,0 +1,3 @@
+test:
+	@echo "Running tests for main and all packages"
+	go test ./...

README.md

@@ -6,7 +6,7 @@ Currently in development.
 - `ffmpeg` make sure libopus is included
 - `yt-dlp`
 
-## Current testing steps
+## Running locally 
 
 Copy .env.example to .env
 
@@ -15,3 +15,7 @@ Populate the discord bot keys
 `go run .`
 
 type `!` in any channel in the discord while you're in a voice channel.
+
+## Running tests locally
+
+`make test`

pkg/validation/validation.go

@@ -0,0 +1,54 @@
+package validation
+
+import (
+	"errors"
+	"fmt"
+	neturl "net/url"
+	"strings"
+)
+
+// Errors
+var (
+	ErrNotAUrl = errors.New("not a URL")
+	ErrIncorrectProtocol = errors.New("incorrect url protocol")
+	ErrServiceUnsupported = errors.New("not a URL")
+)
+
+// Music hosts that we support
+var musicHosts = []string{
+	"youtube.com",
+	"www.youtube.com",
+}
+
+func IsUrl(url string) (bool, *neturl.URL) {
+	// If a URL has no scheme, this will fail.
+	// So we'll add one if not present
+	if !strings.Contains(url, "://") {
+		url = fmt.Sprintf("https://%s", url)
+	}
+
+	parsed, err := neturl.ParseRequestURI(url) 
+
+	return (err == nil), parsed
+}
+
+func IsMusicUrl(url string) (bool, error) {
+	isUrl, parsed := IsUrl(url)
+
+	if !isUrl {
+		return false, ErrNotAUrl 
+	}
+
+	// If we have a scheme and it's not http/https we fail
+	if parsed.Scheme != "" && !strings.Contains(parsed.Scheme, "http") {
+		return false, ErrIncorrectProtocol
+	}
+
+	for _, host := range musicHosts {
+		if host == parsed.Host {
+			return true, nil
+		}
+	}
+
+	return false, ErrServiceUnsupported
+}

pkg/validation/validation_test.go

@@ -0,0 +1,85 @@
+package validation
+
+import (
+	"testing"
+)
+
+func TestIsUrl(t *testing.T) {
+	is, _ := IsUrl("definitely not a url")
+
+	if is {
+		t.Error("Non-url text detected as URL")
+	}
+
+	is, _ = IsUrl("https://example.com")
+
+	if !is {
+		t.Error("URL not detected as URL")
+	}
+}
+
+func TestSchemeHandling(t *testing.T) {
+	// No scheme but valid url
+	is, _ := IsUrl("youtube.com")
+
+	if !is {
+		t.Error("URL without scheme came back as not a url")
+	}
+
+	// Preserve scheme
+	is, parsed := IsUrl("ftp://youtube.com")
+
+	if !is {
+		t.Error("URL without scheme came back as not a url")
+	}
+
+	if parsed.Scheme != "ftp" {
+		t.Error("URL scheme was replaced incorrectly")
+	}
+}
+
+func TestSupportedMusicUrls(t *testing.T) {
+	// Test actual music url
+	for _, url := range musicHosts {
+		is, _ := IsMusicUrl(url)
+
+		if !is {
+			t.Error("Supported service was detected as unsupported")
+		}
+	}
+}
+
+func TestIsMusicUrlErrors(t *testing.T) {
+	// Not a URL
+	is, err := IsMusicUrl("not a url")
+
+	if is {
+		t.Error("Non-URL was detected as url")
+	}
+
+	if err != ErrNotAUrl {
+		t.Error("Incorrect error returned for Non-url link")
+	}
+
+	// Incorrect protocol
+	is, err = IsMusicUrl("ssh://youtube.com")
+
+	if is {
+		t.Error("Incorrect protocol was not caught")
+	}
+
+	if err != ErrIncorrectProtocol {
+		t.Error("Incorrect error returned for incorrect protocol")
+	}
+
+	// Unsupported service
+	is, err = IsMusicUrl("https://www.deezer.com/")
+
+	if is {
+		t.Error("Unsupported service was not caught")
+	}
+
+	if err != ErrServiceUnsupported {
+		t.Error("Unsupported service did not return the correct error")
+	}
+}