Refactor code into package

cmd/list.go

@@ -1,13 +1,8 @@
 package cmd
 
 import (
-	"fmt"
-	"net/http"
-	"os"
-
-	"github.com/bschaatsbergen/tfversion/pkg/download"
+	"github.com/bschaatsbergen/tfversion/pkg/list"
 	"github.com/spf13/cobra"
-	"golang.org/x/net/html"
 )
 
 const (
@@ -27,9 +22,9 @@ var (
 		Example: listExample,
 		Run: func(cmd *cobra.Command, args []string) {
 			if installed {
-				execListInstalled()
+				list.ListInstalledVersions()
 			} else {
-				execList()
+				list.ListAvailableVersions()
 			}
 		},
 	}
@@ -39,47 +34,3 @@ func init() {
 	rootCmd.AddCommand(listCmd)
 	listCmd.Flags().BoolVar(&installed, "installed", false, "list the installed Terraform versions")
 }
-
-func execList() {
-	resp, err := http.Get(download.TerraformReleasesUrl)
-	if err != nil {
-		fmt.Printf("failed to download Terraform: %s", err)
-		os.Exit(1)
-	}
-	defer resp.Body.Close()
-
-	doc, err := html.Parse(resp.Body)
-	if err != nil {
-		fmt.Printf("failed to parse available versions: %s", err)
-		os.Exit(1)
-	}
-
-	var availableVersions []string
-	var processAllVersions func(*html.Node)
-	processAllVersions = func(n *html.Node) {
-		if n.Type == html.ElementNode && n.Data == "a" {
-			availableVersions = append(availableVersions, n.FirstChild.Data)
-		}
-		for c := n.FirstChild; c != nil; c = c.NextSibling {
-			processAllVersions(c)
-		}
-	}
-
-	processAllVersions(doc)
-
-	for _, v := range availableVersions {
-		fmt.Println(v)
-	}
-}
-
-func execListInstalled() {
-	installLocation := download.GetDownloadLocation()
-	installedVersions, err := os.ReadDir(installLocation)
-	if err != nil {
-		fmt.Printf("error listing installation directory: %s", err)
-		os.Exit(1)
-	}
-	for _, v := range installedVersions {
-		fmt.Println(v.Name())
-	}
-}

pkg/list/list.go

@@ -0,0 +1,59 @@
+package list
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/bschaatsbergen/tfversion/pkg/download"
+	"golang.org/x/net/html"
+)
+
+func ListInstalledVersions() {
+	installLocation := download.GetDownloadLocation()
+	installedVersions, err := os.ReadDir(installLocation)
+	if err != nil {
+		fmt.Printf("error listing installation directory: %s", err)
+		os.Exit(1)
+	}
+	for _, v := range installedVersions {
+		fmt.Println(v.Name())
+	}
+}
+
+func ListAvailableVersions() {
+	resp, err := http.Get(download.TerraformReleasesUrl)
+	if err != nil {
+		fmt.Printf("failed to download Terraform: %s", err)
+		os.Exit(1)
+	}
+	defer resp.Body.Close()
+
+	doc, err := html.Parse(resp.Body)
+	if err != nil {
+		fmt.Printf("failed to parse available versions: %s", err)
+		os.Exit(1)
+	}
+
+	availableVersions := parseAvailableVersions(doc)
+	for _, v := range availableVersions {
+		fmt.Println(v)
+	}
+}
+
+func parseAvailableVersions(n *html.Node) []string {
+	var availableVersions []string
+
+	// find available verions in <a> elements
+	if n.Type == html.ElementNode && n.Data == "a" && strings.Contains(n.FirstChild.Data, "terraform") {
+		availableVersions = append(availableVersions, strings.Split(n.FirstChild.Data, "_")[1])
+	}
+
+	// recursively parse DOM elements
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		availableVersions = append(availableVersions, parseAvailableVersions(c)...)
+	}
+
+	return availableVersions
+}