feat: save partial progress when test fails

Author: millotp

gocksnap.go

@@ -58,7 +58,8 @@ type Call struct {
 
 // Snapshot holds the state of the snapshot being recorded, which can include multiple HTTP calls.
 type Snapshot struct {
-	Calls []Call `json:"calls"`
+	Partial bool   `json:"partial,omitempty"`
+	Calls   []Call `json:"calls"`
 
 	// testName used to identify the snapshot file.
 	testName string
@@ -79,19 +80,18 @@ type Snapshot struct {
 	sseConns map[chan string]struct{}
 }
 
-// Finish
-func (g *Snapshot) Finish(t *testing.T) {
-	t.Helper()
-
-	if !g.updateMode {
-		if !gock.IsDone() {
-			t.Fatalf("Snapshot '%s' is not complete. Some requests were not mocked.", g.name)
+func (g *Snapshot) sendMessage(msg string) {
+	for ch := range g.sseConns {
+		select {
+		case ch <- msg:
+		default:
 		}
-
-		return
 	}
+}
+
+func (g *Snapshot) saveToFile(t *testing.T) {
+	t.Helper()
 
-	// Update snapshot
 	data, err := json.MarshalIndent(g, "", "  ")
 	if err != nil {
 		t.Fatalf("Failed to marshal snapshot '%s': %v", g.name, err)
@@ -105,6 +105,35 @@ func (g *Snapshot) Finish(t *testing.T) {
 	}
 }
 
+func (g *Snapshot) attemptToSavePartial(t *testing.T) {
+	t.Helper()
+
+	if !t.Failed() || !g.updateMode || len(g.Calls) == 0 {
+		return
+	}
+
+	g.sendMessage("failedPartial")
+
+	g.Partial = true
+	g.saveToFile(t)
+}
+
+// Finish
+func (g *Snapshot) Finish(t *testing.T) {
+	t.Helper()
+
+	if !g.updateMode {
+		if !gock.IsDone() {
+			t.Fatalf("Snapshot '%s' is not complete. Some requests were not mocked.", g.name)
+		}
+
+		return
+	}
+
+	// Update snapshot
+	g.saveToFile(t)
+}
+
 // file returns the path to the snapshot file.
 func (g *Snapshot) file() string {
 	return filepath.Join(defaultSnapshotDirectory, strings.ReplaceAll(strings.ReplaceAll(g.testName+"-"+g.name, " ", "_"), "/", "_")+".json")
@@ -136,20 +165,15 @@ func (g *Snapshot) promptCall(req *http.Request, existingCall *Call) *Call {
 			Headers:     req.Header,
 			QueryParams: queryParams,
 		},
-		finalCall:        finalCall,
+		finalCall: finalCall,
 	}
 
 	if existingCall != nil {
 		g.pending.ExistingResponse = &existingCall.MockedCall
 	}
 
 	// notify SSE clients
-	for ch := range g.sseConns {
-		select {
-		case ch <- "pending":
-		default:
-		}
-	}
+	g.sendMessage("pending")
 
 	g.mu.Unlock()
 
@@ -190,6 +214,11 @@ func MatchSnapshot(t *testing.T, snapshotName string) *Snapshot {
 			t.Fatalf("Failed to unmarshal snapshot '%s': %v", snapshot.file(), err)
 		}
 
+		if snapshot.Partial {
+			snapshot.updateMode = true
+			snapshot.Partial = false // reset partial flag for the new run
+		}
+
 		if snapshot.updateMode {
 			existingCalls = snapshot.Calls
 			snapshot.Calls = make([]Call, 0)
@@ -209,6 +238,8 @@ func MatchSnapshot(t *testing.T, snapshotName string) *Snapshot {
 	gock.Intercept()
 
 	if snapshot.updateMode {
+		t.Cleanup(func() { snapshot.attemptToSavePartial(t) })
+
 		var existingCall *Call
 		if len(existingCalls) > 0 {
 			existingCall = &existingCalls[0]

index.html

@@ -144,9 +144,14 @@ <h1 id="title">Gocksnap Console</h1>
 
     <script>
         (function () {
+            let isFailed = false;
             const eventSource = new EventSource('/events');
             eventSource.onmessage = function (evt) {
                 if (evt.data === 'pending') fetchCurrent();
+                if (evt.data === 'failedPartial') {
+                    isFailed = true;
+                    document.getElementById('content').innerHTML = '<p id="msg" style="color: red;">⚠️ The test has failed, saving the partial snapshot</p>';
+                }
             };
             fetchCurrent();
 
@@ -201,7 +206,6 @@ <h1 id="title">Gocksnap Console</h1>
 
             function showForm(data) {
                 document.getElementById('title').textContent = "Snapshot for: " + data.name;
-                console.log('existingResponse', data.existingResponse);
                 let optionalFields = '';
                 if (data.request.headers) {
                     optionalFields += createOptionalParamsDiv('headers', 'Headers', Object.entries(data.request.headers).map(([key, value]) => ({
@@ -295,6 +299,9 @@ <h3>Existing Snapshot</h3>
                                 matchingQueryParams: getOptionalParams('queryParams'),
                             }),
                         }).then(function () {
+                            if (isFailed) {
+                                return;
+                            }
                             document.getElementById('content').innerHTML = '<p>✅ Using existing snapshot. Waiting for the next one…</p>';
                         });
                     };