Fix Go code examples in docs, scenarios, and lint warning

Update all Go code examples in docs/, test/scenarios/, and one E2E
test to use per-event type assertions instead of the old flat
event.Data.FieldName pattern.

Fix staticcheck SA5011 lint warning in tools_test.go (nil check
must precede type assertion).

Author: stephentoub

docs/auth/byok.md

@@ -130,7 +130,9 @@ func main() {
         panic(err)
     }
 
-    fmt.Println(*response.Data.Content)
+    if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+        fmt.Println(d.Content)
+    }
 }
 ```
 

docs/features/custom-agents.md

@@ -506,17 +506,17 @@ func main() {
 	})
 
 	session.On(func(event copilot.SessionEvent) {
-		switch event.Type {
-		case "subagent.started":
-			fmt.Printf("▶ Sub-agent started: %s\n", *event.Data.AgentDisplayName)
-			fmt.Printf("  Description: %s\n", *event.Data.AgentDescription)
-			fmt.Printf("  Tool call ID: %s\n", *event.Data.ToolCallID)
-		case "subagent.completed":
-			fmt.Printf("✅ Sub-agent completed: %s\n", *event.Data.AgentDisplayName)
-		case "subagent.failed":
-			fmt.Printf("❌ Sub-agent failed: %s — %v\n", *event.Data.AgentDisplayName, event.Data.Error)
-		case "subagent.selected":
-			fmt.Printf("🎯 Agent selected: %s\n", *event.Data.AgentDisplayName)
+		switch d := event.Data.(type) {
+		case *copilot.SubagentStartedData:
+			fmt.Printf("▶ Sub-agent started: %s\n", d.AgentDisplayName)
+			fmt.Printf("  Description: %s\n", d.AgentDescription)
+			fmt.Printf("  Tool call ID: %s\n", d.ToolCallID)
+		case *copilot.SubagentCompletedData:
+			fmt.Printf("✅ Sub-agent completed: %s\n", d.AgentDisplayName)
+		case *copilot.SubagentFailedData:
+			fmt.Printf("❌ Sub-agent failed: %s — %v\n", d.AgentDisplayName, d.Error)
+		case *copilot.SubagentSelectedData:
+			fmt.Printf("🎯 Agent selected: %s\n", d.AgentDisplayName)
 		}
 	})
 
@@ -530,17 +530,17 @@ func main() {
 
 ```go
 session.On(func(event copilot.SessionEvent) {
-    switch event.Type {
-    case "subagent.started":
-        fmt.Printf("▶ Sub-agent started: %s\n", *event.Data.AgentDisplayName)
-        fmt.Printf("  Description: %s\n", *event.Data.AgentDescription)
-        fmt.Printf("  Tool call ID: %s\n", *event.Data.ToolCallID)
-    case "subagent.completed":
-        fmt.Printf("✅ Sub-agent completed: %s\n", *event.Data.AgentDisplayName)
-    case "subagent.failed":
-        fmt.Printf("❌ Sub-agent failed: %s — %v\n", *event.Data.AgentDisplayName, event.Data.Error)
-    case "subagent.selected":
-        fmt.Printf("🎯 Agent selected: %s\n", *event.Data.AgentDisplayName)
+    switch d := event.Data.(type) {
+    case *copilot.SubagentStartedData:
+        fmt.Printf("▶ Sub-agent started: %s\n", d.AgentDisplayName)
+        fmt.Printf("  Description: %s\n", d.AgentDescription)
+        fmt.Printf("  Tool call ID: %s\n", d.ToolCallID)
+    case *copilot.SubagentCompletedData:
+        fmt.Printf("✅ Sub-agent completed: %s\n", d.AgentDisplayName)
+    case *copilot.SubagentFailedData:
+        fmt.Printf("❌ Sub-agent failed: %s — %v\n", d.AgentDisplayName, d.Error)
+    case *copilot.SubagentSelectedData:
+        fmt.Printf("🎯 Agent selected: %s\n", d.AgentDisplayName)
     }
 })
 

docs/features/streaming-events.md

@@ -137,8 +137,8 @@ func main() {
 	})
 
 	session.On(func(event copilot.SessionEvent) {
-		if event.Type == "assistant.message_delta" {
-			fmt.Print(*event.Data.DeltaContent)
+		if d, ok := event.Data.(*copilot.AssistantMessageDeltaData); ok {
+			fmt.Print(d.DeltaContent)
 		}
 	})
 	_ = session
@@ -148,8 +148,8 @@ func main() {
 
 ```go
 session.On(func(event copilot.SessionEvent) {
-    if event.Type == "assistant.message_delta" {
-        fmt.Print(*event.Data.DeltaContent)
+    if d, ok := event.Data.(*copilot.AssistantMessageDeltaData); ok {
+        fmt.Print(d.DeltaContent)
     }
 })
 ```

docs/getting-started.md

@@ -211,7 +211,9 @@ func main() {
 		log.Fatal(err)
 	}
 
-	fmt.Println(*response.Data.Content)
+	if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+		fmt.Println(d.Content)
+	}
 	os.Exit(0)
 }
 ```
@@ -406,10 +408,11 @@ func main() {
 
 	// Listen for response chunks
 	session.On(func(event copilot.SessionEvent) {
-		if event.Type == "assistant.message_delta" {
-			fmt.Print(*event.Data.DeltaContent)
-		}
-		if event.Type == "session.idle" {
+		switch d := event.Data.(type) {
+		case *copilot.AssistantMessageDeltaData:
+			fmt.Print(d.DeltaContent)
+		case *copilot.SessionIdleData:
+			_ = d
 			fmt.Println()
 		}
 	})
@@ -604,10 +607,12 @@ func main() {
 
 	// Filter by event type in your handler
 	session.On(func(event copilot.SessionEvent) {
-		if event.Type == "session.idle" {
+		switch d := event.Data.(type) {
+		case *copilot.SessionIdleData:
+			_ = d
 			fmt.Println("Session is idle")
-		} else if event.Type == "assistant.message" {
-			fmt.Println("Message:", *event.Data.Content)
+		case *copilot.AssistantMessageData:
+			fmt.Println("Message:", d.Content)
 		}
 	})
 
@@ -625,10 +630,12 @@ unsubscribe := session.On(func(event copilot.SessionEvent) {
 
 // Filter by event type in your handler
 session.On(func(event copilot.SessionEvent) {
-    if event.Type == "session.idle" {
+    switch d := event.Data.(type) {
+    case *copilot.SessionIdleData:
+        _ = d
         fmt.Println("Session is idle")
-    } else if event.Type == "assistant.message" {
-        fmt.Println("Message:", *event.Data.Content)
+    case *copilot.AssistantMessageData:
+        fmt.Println("Message:", d.Content)
     }
 })
 
@@ -897,10 +904,11 @@ func main() {
 	}
 
 	session.On(func(event copilot.SessionEvent) {
-		if event.Type == "assistant.message_delta" {
-			fmt.Print(*event.Data.DeltaContent)
-		}
-		if event.Type == "session.idle" {
+		switch d := event.Data.(type) {
+		case *copilot.AssistantMessageDeltaData:
+			fmt.Print(d.DeltaContent)
+		case *copilot.SessionIdleData:
+			_ = d
 			fmt.Println()
 		}
 	})
@@ -1251,12 +1259,11 @@ func main() {
 	}
 
 	session.On(func(event copilot.SessionEvent) {
-		if event.Type == "assistant.message_delta" {
-			if event.Data.DeltaContent != nil {
-				fmt.Print(*event.Data.DeltaContent)
-			}
-		}
-		if event.Type == "session.idle" {
+		switch d := event.Data.(type) {
+		case *copilot.AssistantMessageDeltaData:
+			fmt.Print(d.DeltaContent)
+		case *copilot.SessionIdleData:
+			_ = d
 			fmt.Println()
 		}
 	})

docs/setup/bundled-cli.md

@@ -130,7 +130,9 @@ func main() {
 
 	session, _ := client.CreateSession(ctx, &copilot.SessionConfig{Model: "gpt-4.1"})
 	response, _ := session.SendAndWait(ctx, copilot.MessageOptions{Prompt: "Hello!"})
-	fmt.Println(*response.Data.Content)
+	if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+		fmt.Println(d.Content)
+	}
 }
 ```
 <!-- /docs-validate: hidden -->
@@ -146,7 +148,9 @@ defer client.Stop()
 
 session, _ := client.CreateSession(ctx, &copilot.SessionConfig{Model: "gpt-4.1"})
 response, _ := session.SendAndWait(ctx, copilot.MessageOptions{Prompt: "Hello!"})
-fmt.Println(*response.Data.Content)
+if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+    fmt.Println(d.Content)
+}
 ```
 
 </details>

docs/setup/local-cli.md

@@ -91,7 +91,9 @@ func main() {
 
 	session, _ := client.CreateSession(ctx, &copilot.SessionConfig{Model: "gpt-4.1"})
 	response, _ := session.SendAndWait(ctx, copilot.MessageOptions{Prompt: "Hello!"})
-	fmt.Println(*response.Data.Content)
+	if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+		fmt.Println(d.Content)
+	}
 }
 ```
 <!-- /docs-validate: hidden -->
@@ -105,7 +107,9 @@ defer client.Stop()
 
 session, _ := client.CreateSession(ctx, &copilot.SessionConfig{Model: "gpt-4.1"})
 response, _ := session.SendAndWait(ctx, copilot.MessageOptions{Prompt: "Hello!"})
-fmt.Println(*response.Data.Content)
+if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+    fmt.Println(d.Content)
+}
 ```
 
 </details>

go/internal/e2e/session_fs_test.go

@@ -48,8 +48,10 @@ func TestSessionFs(t *testing.T) {
 			t.Fatalf("Failed to send message: %v", err)
 		}
 		content := ""
-		if msg != nil && msg.Data.Content != nil {
-			content = *msg.Data.Content
+		if msg != nil {
+			if d, ok := msg.Data.(*copilot.AssistantMessageData); ok {
+				content = d.Content
+			}
 		}
 		if !strings.Contains(content, "300") {
 			t.Fatalf("Expected response to contain 300, got %q", content)
@@ -84,8 +86,10 @@ func TestSessionFs(t *testing.T) {
 			t.Fatalf("Failed to send first message: %v", err)
 		}
 		content := ""
-		if msg != nil && msg.Data.Content != nil {
-			content = *msg.Data.Content
+		if msg != nil {
+			if d, ok := msg.Data.(*copilot.AssistantMessageData); ok {
+				content = d.Content
+			}
 		}
 		if !strings.Contains(content, "100") {
 			t.Fatalf("Expected response to contain 100, got %q", content)
@@ -111,8 +115,10 @@ func TestSessionFs(t *testing.T) {
 			t.Fatalf("Failed to send second message: %v", err)
 		}
 		content2 := ""
-		if msg2 != nil && msg2.Data.Content != nil {
-			content2 = *msg2.Data.Content
+		if msg2 != nil {
+			if d, ok := msg2.Data.(*copilot.AssistantMessageData); ok {
+				content2 = d.Content
+			}
 		}
 		if !strings.Contains(content2, "300") {
 			t.Fatalf("Expected response to contain 300, got %q", content2)
@@ -396,24 +402,20 @@ func providerPath(root string, sessionID string, path string) string {
 
 func findToolCallResult(messages []copilot.SessionEvent, toolName string) string {
 	for _, message := range messages {
-		if message.Type == "tool.execution_complete" &&
-			message.Data.Result != nil &&
-			message.Data.Result.Content != nil &&
-			message.Data.ToolCallID != nil &&
-			findToolName(messages, *message.Data.ToolCallID) == toolName {
-			return *message.Data.Result.Content
+		if d, ok := message.Data.(*copilot.ToolExecutionCompleteData); ok &&
+			d.Result != nil &&
+			findToolName(messages, d.ToolCallID) == toolName {
+			return d.Result.Content
 		}
 	}
 	return ""
 }
 
 func findToolName(messages []copilot.SessionEvent, toolCallID string) string {
 	for _, message := range messages {
-		if message.Type == "tool.execution_start" &&
-			message.Data.ToolCallID != nil &&
-			*message.Data.ToolCallID == toolCallID &&
-			message.Data.ToolName != nil {
-			return *message.Data.ToolName
+		if d, ok := message.Data.(*copilot.ToolExecutionStartData); ok &&
+			d.ToolCallID == toolCallID {
+			return d.ToolName
 		}
 	}
 	return ""

go/internal/e2e/tools_test.go

@@ -232,8 +232,11 @@ func TestTools(t *testing.T) {
 			t.Fatalf("Failed to get assistant message: %v", err)
 		}
 
+		if answer == nil {
+			t.Fatalf("Expected assistant message with content")
+		}
 		ad, ok := answer.Data.(*copilot.AssistantMessageData)
-		if answer == nil || !ok {
+		if !ok {
 			t.Fatalf("Expected assistant message with content")
 		}
 

test/scenarios/auth/byok-anthropic/go/main.go

@@ -58,7 +58,9 @@ func main() {
 		log.Fatal(err)
 	}
 
-	if response != nil && response.Data.Content != nil {
-		fmt.Println(*response.Data.Content)
-	}
+	if response != nil {
+if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+fmt.Println(d.Content)
+}
+}
 }

test/scenarios/auth/byok-azure/go/main.go

@@ -62,7 +62,9 @@ func main() {
 		log.Fatal(err)
 	}
 
-	if response != nil && response.Data.Content != nil {
-		fmt.Println(*response.Data.Content)
-	}
+	if response != nil {
+if d, ok := response.Data.(*copilot.AssistantMessageData); ok {
+fmt.Println(d.Content)
+}
+}
 }