Mark rate-limit as experimental

pkg/workflow/compiler.go

@@ -222,6 +222,12 @@ func (c *Compiler) validateWorkflowData(workflowData *WorkflowData, markdownPath
 		c.IncrementWarningCount()
 	}
 
+	// Emit experimental warning for rate-limit feature
+	if workflowData.RateLimit != nil {
+		fmt.Fprintln(os.Stderr, console.FormatWarningMessage("Using experimental feature: rate-limit"))
+		c.IncrementWarningCount()
+	}
+
 	// Validate workflow_run triggers have branch restrictions
 	log.Printf("Validating workflow_run triggers for branch restrictions")
 	if err := c.validateWorkflowRunBranches(workflowData, markdownPath); err != nil {

pkg/workflow/rate_limit_experimental_warning_test.go

@@ -0,0 +1,153 @@
+//go:build integration
+
+package workflow
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/github/gh-aw/pkg/testutil"
+)
+
+// TestRateLimitExperimentalWarning tests that the rate-limit feature
+// emits an experimental warning when enabled.
+func TestRateLimitExperimentalWarning(t *testing.T) {
+	tests := []struct {
+		name          string
+		content       string
+		expectWarning bool
+	}{
+		{
+			name: "rate-limit enabled produces experimental warning",
+			content: `---
+on: workflow_dispatch
+engine: copilot
+rate-limit:
+  max: 5
+  window: 60
+permissions:
+  contents: read
+  issues: read
+  pull-requests: read
+---
+
+# Test Workflow
+`,
+			expectWarning: true,
+		},
+		{
+			name: "no rate-limit does not produce experimental warning",
+			content: `---
+on: workflow_dispatch
+engine: copilot
+permissions:
+  contents: read
+  issues: read
+  pull-requests: read
+---
+
+# Test Workflow
+`,
+			expectWarning: false,
+		},
+		{
+			name: "rate-limit with custom ignored roles produces experimental warning",
+			content: `---
+on: workflow_dispatch
+engine: copilot
+rate-limit:
+  max: 3
+  window: 30
+  ignored-roles:
+    - admin
+    - maintain
+permissions:
+  contents: read
+  issues: read
+  pull-requests: read
+---
+
+# Test Workflow
+`,
+			expectWarning: true,
+		},
+		{
+			name: "rate-limit with events produces experimental warning",
+			content: `---
+on:
+  workflow_dispatch:
+  issue_comment:
+    types: [created]
+engine: copilot
+rate-limit:
+  max: 5
+  window: 60
+  events: [workflow_dispatch, issue_comment]
+permissions:
+  contents: read
+  issues: read
+  pull-requests: read
+---
+
+# Test Workflow
+`,
+			expectWarning: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir := testutil.TempDir(t, "rate-limit-experimental-warning-test")
+
+			testFile := filepath.Join(tmpDir, "test-workflow.md")
+			if err := os.WriteFile(testFile, []byte(tt.content), 0644); err != nil {
+				t.Fatal(err)
+			}
+
+			// Capture stderr to check for warnings
+			oldStderr := os.Stderr
+			r, w, _ := os.Pipe()
+			os.Stderr = w
+
+			compiler := NewCompiler()
+			compiler.SetStrictMode(false)
+			err := compiler.CompileWorkflow(testFile)
+
+			// Restore stderr
+			w.Close()
+			os.Stderr = oldStderr
+			var buf bytes.Buffer
+			io.Copy(&buf, r)
+			stderrOutput := buf.String()
+
+			if err != nil {
+				t.Errorf("Expected compilation to succeed but it failed: %v", err)
+				return
+			}
+
+			expectedMessage := "Using experimental feature: rate-limit"
+
+			if tt.expectWarning {
+				if !strings.Contains(stderrOutput, expectedMessage) {
+					t.Errorf("Expected warning containing '%s', got stderr:\n%s", expectedMessage, stderrOutput)
+				}
+			} else {
+				if strings.Contains(stderrOutput, expectedMessage) {
+					t.Errorf("Did not expect warning '%s', but got stderr:\n%s", expectedMessage, stderrOutput)
+				}
+			}
+
+			// Verify warning count includes rate-limit warning
+			if tt.expectWarning {
+				warningCount := compiler.GetWarningCount()
+				if warningCount == 0 {
+					t.Error("Expected warning count > 0 but got 0")
+				}
+			}
+		})
+	}
+}