chore: decompress response body

Author: fmenezes

test/e2e/atlas_e2e_test_generator_test.go

@@ -16,6 +16,8 @@ package e2e_test
 
 import (
 	"bytes"
+	"compress/flate"
+	"compress/gzip"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@@ -28,6 +30,8 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"slices"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -54,6 +58,59 @@ type snapshotData struct {
 	Headers map[string][]string
 }
 
+func (d snapshotData) Decompress() error {
+	for _, encoding := range d.Headers["Content-Encoding"] {
+		switch encoding {
+		case "gzip", "x-gzip":
+			return d.decompressGzip()
+		case "deflate":
+			return d.decompressDeflate()
+		}
+	}
+
+	return nil
+}
+
+func (d snapshotData) removeContentEncoding() {
+	d.Headers["Content-Encoding"] = nil
+	vary := d.Headers["Vary"]
+	if len(vary) != 0 {
+		vary = slices.DeleteFunc(vary, func(s string) bool {
+			return strings.EqualFold(s, "accept-encoding")
+		})
+		d.Headers["Vary"] = vary
+	}
+}
+
+func (d snapshotData) decompressGzip() error {
+	reader, err := gzip.NewReader(bytes.NewReader(d.Body))
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+	buf := new(bytes.Buffer)
+	if _, err := io.Copy(buf, reader); err != nil {
+		return err
+	}
+	d.Body = buf.Bytes()
+	d.Headers["Content-Length"] = []string{strconv.Itoa(len(d.Body))}
+	d.removeContentEncoding()
+	return nil
+}
+
+func (d snapshotData) decompressDeflate() error {
+	reader := flate.NewReader(bytes.NewReader(d.Body))
+	defer reader.Close()
+	buf := new(bytes.Buffer)
+	if _, err := io.Copy(buf, reader); err != nil {
+		return err
+	}
+	d.Body = buf.Bytes()
+	d.Headers["Content-Length"] = []string{strconv.Itoa(len(d.Body))}
+	d.removeContentEncoding()
+	return nil
+}
+
 func (d snapshotData) Compare(v snapshotData) int {
 	methodCmp := strings.Compare(d.Method, v.Method)
 	if methodCmp != 0 {
@@ -558,6 +615,10 @@ func (g *atlasE2ETestGenerator) snapshotServer() {
 
 		data.Body = buf.Bytes()
 
+		if err := data.Decompress(); err != nil {
+			return err
+		}
+
 		if g.lastData != nil && data.Compare(*g.lastData) == 0 {
 			return nil // skip same content
 		}