Bug fix: Allow multiple environment variables to be set to the same S…

…SM parameter via name (#326)

* added test for multiple ssm names with same path

* stop inverting userParams object; allow multiple SSM names with same path

* remove Object.entries for node 6 support

* only fetch duplicated SSM params once

* version bump

package.json

@@ -1,6 +1,6 @@
 {
   "name": "middy",
-  "version": "0.25.0",
+  "version": "0.25.1",
   "description": "🛵 The stylish Node.js middleware engine for AWS Lambda",
   "main": "./index.js",
   "files": [

src/middlewares/__tests__/ssm.js

@@ -392,4 +392,27 @@ describe('🔒 SSM Middleware', () => {
       done
     })
   })
+
+  test('It should allow multiple option names to point at the same SSM path', (done) => {
+    testScenario({
+      ssmMockResponses: [
+        {
+          Parameters: [{ Name: '/dev/service_name/key_name', Value: 'key-value' }]
+        }
+      ],
+      middlewareOptions: {
+        names: {
+          KEY_NAME_1: '/dev/service_name/key_name',
+          KEY_NAME_2: '/dev/service_name/key_name'
+        }
+      },
+      callbacks: [
+        () => {
+          expect(process.env.KEY_NAME_1).toEqual('key-value')
+          expect(process.env.KEY_NAME_2).toEqual('key-value')
+        }
+      ],
+      done
+    })
+  })
 })

src/middlewares/ssm.js

@@ -56,7 +56,6 @@ module.exports = opts => {
         },
         []
       )
-
       const ssmParamNames = getSSMParamValues(options.names)
       if (ssmParamNames.length) {
         const ssmPromise = ssmInstance
@@ -149,7 +148,7 @@ const getTargetObjectToAssign = (handler, options) =>
   options.setToContext ? handler.context : process.env
 
 const getSSMParamValues = userParamsMap =>
-  Object.keys(userParamsMap).map(key => userParamsMap[key])
+  [...new Set(Object.keys(userParamsMap).map(key => userParamsMap[key]))]
 
 /**
  * Lazily load aws-sdk and initialize SSM constructor
@@ -191,11 +190,9 @@ const handleInvalidParams = ({ Parameters, InvalidParameters }) => {
  * @return {Object} Merged object for assignment to target object
  */
 const getParamsToAssignByName = (userParamsMap, ssmParams) => {
-  const ssmToUserParamsMap = invertObject(userParamsMap)
-
-  return ssmParams.reduce((aggregator, ssmParam) => {
-    aggregator[ssmToUserParamsMap[ssmParam.Name]] = ssmParam.Value
-    return aggregator
+  return Object.keys(userParamsMap).reduce((acc, key) => {
+    acc[key] = ssmParams.find(param => param.Name === userParamsMap[key]).Value
+    return acc
   }, {})
 }
 
@@ -218,9 +215,3 @@ const getParamsToAssignByPath = (
       ssmParam.Value
     return aggregator
   }, {})
-
-const invertObject = obj =>
-  Object.keys(obj).reduce((aggregator, key) => {
-    aggregator[obj[key]] = key
-    return aggregator
-  }, {})