models/apis: adding validation to ensure collision of api defintions do not occur

models/apis/check_collisions_test.go

@@ -0,0 +1,35 @@
+// +build awsinclude
+
+package apis
+
+import (
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+func TestCollidingFolders(t *testing.T) {
+	m := map[string]struct{}{}
+	folders, err := getFolderNames()
+	if err != nil {
+		t.Error(err)
+	}
+
+	for _, folder := range folders {
+		lcName := strings.ToLower(folder)
+		if _, ok := m[lcName]; ok {
+			t.Errorf("folder %q collision detected", folder)
+		}
+		m[lcName] = struct{}{}
+	}
+}
+
+func getFolderNames() ([]string, error) {
+	cmd := exec.Command("git", "ls-tree", "-d", "--name-only", "HEAD")
+	output, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+
+	return strings.Split(string(output), "\n"), nil
+}

models/apis/stub.go

@@ -0,0 +1,3 @@
+// +build awsinclude
+
+package apis

private/model/cli/gen-api/main.go

@@ -131,7 +131,7 @@ func main() {
 
 	for svcName := range excludeServices {
 		if strings.Contains(os.Getenv("SERVICES"), svcName) {
-			fmt.Printf("Service %s is not supported\n", svcName)
+			fmt.Fprintf(os.Stderr, "Service %s is not supported\n", svcName)
 			os.Exit(1)
 		}
 	}
@@ -140,6 +140,10 @@ func main() {
 
 	// Remove old API versions from list
 	m := map[string]bool{}
+	// caches paths to ensure we are not overriding previously generated
+	// code.
+	servicePaths := map[string]struct{}{}
+
 	for i := range files {
 		idx := len(files) - 1 - i
 		parts := strings.Split(files[idx], string(filepath.Separator))
@@ -167,6 +171,13 @@ func main() {
 			continue
 		}
 
+		if _, ok := servicePaths[genInfo.PackageDir]; ok {
+			fmt.Fprintf(os.Stderr, "Path %q has already been generated", genInfo.PackageDir)
+			os.Exit(1)
+		}
+
+		servicePaths[genInfo.PackageDir] = struct{}{}
+
 		wg.Add(1)
 		go func(g *generateInfo, filename string) {
 			defer wg.Done()