Add marshaling and unmarshaling of API objects so state can be persisted between runs

scraper/api_request_utils.go

@@ -24,6 +24,53 @@ type API struct {
 	CSRFToken       string
 }
 
+type api_outstruct struct {
+	Cookies         []*http.Cookie
+	UserHandle      UserHandle
+	IsAuthenticated bool
+	GuestToken      string
+	CSRFToken       string
+}
+
+var TWITTER_BASE_URL = url.URL{Scheme: "https", Host: "twitter.com"}
+
+func (api API) MarshalJSON() ([]byte, error) {
+	result, err := json.Marshal(api_outstruct{
+		Cookies:         api.Client.Jar.Cookies(&TWITTER_BASE_URL),
+		UserHandle:      api.UserHandle,
+		IsAuthenticated: api.IsAuthenticated,
+		GuestToken:      api.GuestToken,
+		CSRFToken:       api.CSRFToken,
+	})
+	if err != nil {
+		return result, fmt.Errorf("Unable to JSONify the api:\n  %w", err)
+	}
+	return result, nil
+}
+
+func (api *API) UnmarshalJSON(data []byte) error {
+	var in_struct api_outstruct
+	err := json.Unmarshal(data, &in_struct)
+	if err != nil {
+		return fmt.Errorf("Unable to unmarshal:\n  %w", err)
+	}
+	cookie_jar, err := cookiejar.New(nil)
+	if err != nil {
+		panic(err)
+	}
+	cookie_jar.SetCookies(&TWITTER_BASE_URL, in_struct.Cookies)
+	api.IsAuthenticated = in_struct.IsAuthenticated
+	api.GuestToken = in_struct.GuestToken
+	api.UserHandle = in_struct.UserHandle
+
+	api.Client = http.Client{
+		Timeout: 10 * time.Second,
+		Jar:     cookie_jar,
+	}
+	api.CSRFToken = in_struct.CSRFToken
+	return nil
+}
+
 func (api API) add_authentication_headers(req *http.Request) {
 	// Params for every request
 	req.Header.Set("Authorization", "Bearer "+BEARER_TOKEN)

scraper/authentication_test.go

@@ -1,13 +1,21 @@
 package scraper_test
 
 import (
-	. "offline_twitter/scraper"
+	"encoding/json"
 	"testing"
+	"time"
 
+	"net/http"
+	"net/http/cookiejar"
+
+	"github.com/go-test/deep"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	. "offline_twitter/scraper"
 )
 
+// TODO authentication: this has to be removed and replaced with an integration test once the feature is stable-ish
 func TestAuthentication(t *testing.T) {
 	assert := assert.New(t)
 	require := require.New(t)
@@ -28,3 +36,41 @@ func TestAuthentication(t *testing.T) {
 	require.NoError(err)
 	assert.True(len(trove.Tweets) > 0)
 }
+
+// An API object should serialize and then deserialize to give the same session state from before.
+func TestJsonifyApi(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
+
+	cookie_jar, err := cookiejar.New(nil)
+	require.NoError(err)
+	cookie_jar.SetCookies(&TWITTER_BASE_URL, []*http.Cookie{
+		{Name: "name1", Value: "name1", Secure: true},
+		{Name: "name2", Value: "name2", HttpOnly: true},
+	})
+	api := API{
+		UserHandle:      UserHandle("userhandle"),
+		IsAuthenticated: true,
+		GuestToken:      "guest token",
+		Client: http.Client{
+			Timeout: 10 * time.Second,
+			Jar:     cookie_jar,
+		},
+		CSRFToken: "csrf token",
+	}
+
+	bytes, err := json.Marshal(api)
+	require.NoError(err)
+	var new_api API
+	err = json.Unmarshal(bytes, &new_api)
+	require.NoError(err)
+
+	cookies := api.Client.Jar.Cookies(&TWITTER_BASE_URL)
+
+	assert.Equal(cookies[0].Name, "name1")
+	assert.Equal(cookies[0].Value, "name1")
+
+	if diff := deep.Equal(api, new_api); diff != nil {
+		t.Error(diff)
+	}
+}