Fix update not properly decompress content (#52)

* Fix update not properly decompress content

* Fix unit test

pkg/commands/update/update.go

@@ -1,6 +1,8 @@
 package update
 
 import (
+	"archive/tar"
+	"compress/gzip"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -108,7 +110,7 @@ func updateCLI(iostream *iostreams.IOStreams) error {
 	installPath := filepath.Join(installDir, "mycli")
 
 	// Create a temporary file
-	tmpFile, err := os.CreateTemp("", "mycli-update")
+	tmpFile, err := os.CreateTemp("", "mycli-update-*.tar.gz")
 	if err != nil {
 		return fmt.Errorf("failed to create temporary file: %w", err)
 	}
@@ -121,18 +123,62 @@ func updateCLI(iostream *iostreams.IOStreams) error {
 	}
 	tmpFile.Close()
 
-	// Make the temporary file executable
-	if err := os.Chmod(tmpFile.Name(), 0755); err != nil {
-		return fmt.Errorf("failed to make new binary executable: %w", err)
+	// Open the temporary file for reading
+	tmpFile, err = os.Open(tmpFile.Name())
+	if err != nil {
+		return fmt.Errorf("failed to open temporary file: %w", err)
 	}
+	defer tmpFile.Close()
 
-	// Replace the old binary with the new one
-	if err := os.Rename(tmpFile.Name(), installPath); err != nil {
-		return fmt.Errorf("failed to replace old binary: %w", err)
+	// Create a gzip reader
+	gzr, err := gzip.NewReader(tmpFile)
+	if err != nil {
+		return fmt.Errorf("failed to create gzip reader: %w", err)
 	}
+	defer gzr.Close()
 
-	fmt.Fprintf(iostream.Out, "mycli has been updated successfully to version %s!\n", release.TagName)
-	return nil
+	// Create a tar reader
+	tr := tar.NewReader(gzr)
+
+	// Extract the mycli binary
+	for {
+		header, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("failed to read tar: %w", err)
+		}
+
+		if header.Name == "mycli" {
+			// Create a new temporary file for the extracted binary
+			extractedTmp, err := os.CreateTemp("", "mycli-extracted")
+			if err != nil {
+				return fmt.Errorf("failed to create temporary file for extracted binary: %w", err)
+			}
+			defer os.Remove(extractedTmp.Name())
+
+			// Copy the file contents
+			if _, err := io.Copy(extractedTmp, tr); err != nil {
+				return fmt.Errorf("failed to extract binary: %w", err)
+			}
+			extractedTmp.Close()
+
+			// Make the temporary file executable
+			if err := os.Chmod(extractedTmp.Name(), 0755); err != nil {
+				return fmt.Errorf("failed to make new binary executable: %w", err)
+			}
+
+			// Replace the old binary with the new one
+			if err := os.Rename(extractedTmp.Name(), installPath); err != nil {
+				return fmt.Errorf("failed to replace old binary: %w", err)
+			}
+
+			fmt.Fprintf(iostream.Out, "mycli has been updated successfully to version %s!\n", release.TagName)
+			return nil
+		}
+	}
+	return fmt.Errorf("failed to find mycli binary in the downloaded archive")
 }
 
 var ensureInstallDirectory = func() (string, error) {

pkg/commands/update/update_test.go

@@ -1,6 +1,9 @@
 package update
 
 import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
@@ -74,11 +77,45 @@ func TestUpdateCLI(t *testing.T) {
 	err = os.WriteFile(mockBinaryPath, []byte("old binary"), 0755)
 	assert.NoError(t, err)
 
+	// Create a mock binary content
+	mockBinaryContent := []byte("new binary")
+
+	// Create a buffer to hold the tar.gz content
+	var buf bytes.Buffer
+
+	// Create a gzip writer
+	gw := gzip.NewWriter(&buf)
+
+	// Create a tar writer
+	tw := tar.NewWriter(gw)
+
+	// Add the mock binary to the tar archive
+	hdr := &tar.Header{
+		Name: "mycli",
+		Mode: 0755,
+		Size: int64(len(mockBinaryContent)),
+	}
+	if err := tw.WriteHeader(hdr); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := tw.Write(mockBinaryContent); err != nil {
+		t.Fatal(err)
+	}
+	// Close the tar writer
+	if err := tw.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	// Close the gzip writer
+	if err := gw.Close(); err != nil {
+		t.Fatal(err)
+	}
+
 	// Mock server
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Type", "application/gzip")
 		w.WriteHeader(http.StatusOK)
-		if _, err := w.Write([]byte("new binary")); err != nil {
+		if _, err := w.Write(buf.Bytes()); err != nil {
 			return
 		}
 	}))