feat(remote.Client): Add current context to Fetch and FetchV2 (#29)

* chore: Allow providing an externally created http client for the remote client.

* Pass the current context to Fetch and FetchV2

* Create a new method instead of generate breaking changes to current ones.

* Reorder FetchV2WithContext signature

---------

Co-authored-by: Hugo Biarge <[email protected]>

pkg/experiment/remote/client.go

@@ -42,6 +42,7 @@ func Initialize(apiKey string, config *Config) *Client {
 			client: &http.Client{},
 		}
 		client.log.Debug("config: %v", *config)
+		clients[apiKey] = client
 	}
 	initMutex.Unlock()
 	return client
@@ -60,19 +61,25 @@ func (c *Client) Fetch(user *experiment.User) (map[string]experiment.Variant, er
 // FetchV2 fetches variants for a user from the remote evaluation service.
 // Unlike Fetch, this method returns all variants, including default variants.
 func (c *Client) FetchV2(user *experiment.User) (map[string]experiment.Variant, error) {
-	variants, err := c.doFetch(user, c.config.FetchTimeout)
+	ctx := context.Background()
+	return c.FetchV2WithContext(user, ctx)
+}
+
+// FetchV2WithContext fetches variants for a user from the remote evaluation service with a context.
+func (c *Client) FetchV2WithContext(user *experiment.User, ctx context.Context) (map[string]experiment.Variant, error) {
+	variants, err := c.doFetch(ctx, user, c.config.FetchTimeout)
 	if err != nil {
 		c.log.Error("fetch error: %v", err)
 		if c.config.RetryBackoff.FetchRetries > 0 && shouldRetryFetch(err) {
-			return c.retryFetch(user)
+			return c.retryFetch(ctx, user)
 		} else {
 			return nil, err
 		}
 	}
 	return variants, err
 }
 
-func (c *Client) doFetch(user *experiment.User, timeout time.Duration) (map[string]experiment.Variant, error) {
+func (c *Client) doFetch(ctx context.Context, user *experiment.User, timeout time.Duration) (map[string]experiment.Variant, error) {
 	addLibraryContext(user)
 	endpoint, err := url.Parse(c.config.ServerUrl)
 	if err != nil {
@@ -87,7 +94,7 @@ func (c *Client) doFetch(user *experiment.User, timeout time.Duration) (map[stri
 		return nil, err
 	}
 	c.log.Debug("fetch variants for user %s", string(jsonBytes))
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	ctx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 	req, err := http.NewRequestWithContext(ctx, "GET", endpoint.String(), nil)
 	if err != nil {
@@ -109,7 +116,7 @@ func (c *Client) doFetch(user *experiment.User, timeout time.Duration) (map[stri
 	return c.parseResponse(resp)
 }
 
-func (c *Client) retryFetch(user *experiment.User) (map[string]experiment.Variant, error) {
+func (c *Client) retryFetch(ctx context.Context, user *experiment.User) (map[string]experiment.Variant, error) {
 	var err error
 	var variants map[string]experiment.Variant
 	var timer *time.Timer
@@ -118,7 +125,7 @@ func (c *Client) retryFetch(user *experiment.User) (map[string]experiment.Varian
 		c.log.Debug("retry attempt %v", i)
 		timer = time.NewTimer(delay)
 		<-timer.C
-		variants, err = c.doFetch(user, c.config.RetryBackoff.FetchRetryTimeout)
+		variants, err = c.doFetch(ctx, user, c.config.RetryBackoff.FetchRetryTimeout)
 		if err == nil && variants != nil {
 			c.log.Debug("retry attempt %v success", i)
 			return variants, nil

pkg/experiment/remote/client_test.go

@@ -22,7 +22,6 @@ func TestClient_Fetch_DoesNotReturnDefaultVariants(t *testing.T) {
 	require.Empty(t, variant)
 }
 
-
 func TestClient_FetchV2_ReturnsDefaultVariants(t *testing.T) {
 	client := Initialize("server-qz35UwzJ5akieoAdIgzM4m9MIiOLXLoz", nil)
 	user := &experiment.User{}

pkg/experiment/remote/config.go

@@ -1,6 +1,8 @@
 package remote
 
-import "time"
+import (
+	"time"
+)
 
 type Config struct {
 	Debug        bool