add validStages feature

Author: horike37

README.md

@@ -32,3 +32,13 @@ Run deploy
 ```
 $ serverless deploy
 ```
+
+You can specify additional configurations a `lambdaEdgePreExistingCloudFront` value in the custom section of your serverless.yml file.
+A `validStages` value allows you to specify valid stage names for deploy Lambda@Edge.
+
+```yaml
+lambdaEdgePreExistingCloudFront:
+  validStages:
+    - staging
+    - production
+```

index.js

@@ -15,7 +15,7 @@ class ServerlessLambdaEdgePreExistingCloudFront {
           const functionObj = this.serverless.service.getFunction(functionName)
           if (functionObj.events) {
             functionObj.events.forEach(async (event) => {
-              if (event.preExistingCloudFront) {
+              if (event.preExistingCloudFront && this.checkAllowedDeployStage()) {
                 const functionArn = await this.getlatestVersionLambdaArn(functionObj.name)
                 const config = await this.provider.request('CloudFront', 'getDistribution', {
                   Id: event.preExistingCloudFront.distributionId
@@ -53,6 +53,23 @@ class ServerlessLambdaEdgePreExistingCloudFront {
     }
   }
 
+  checkAllowedDeployStage() {
+    if (
+      this.serverless.service.custom &&
+      this.serverless.service.custom.lambdaEdgePreExistingCloudFront &&
+      this.serverless.service.custom.lambdaEdgePreExistingCloudFront.validStages
+    ) {
+      if (
+        this.serverless.service.custom.lambdaEdgePreExistingCloudFront.validStages.indexOf(
+          this.stage
+        ) < 0
+      ) {
+        return false
+      }
+    }
+    return true
+  }
+
   async associateNonDefaultCacheBehaviors(cacheBehaviors, event, functionName, functionArn) {
     for (let i = 0; i < cacheBehaviors.Items.length; i++) {
       if (event.preExistingCloudFront.pathPattern === cacheBehaviors.Items[i].PathPattern) {