feat(cf.findInMap): Default Value Support For Fn::FindInMap (#156)

bilindhajer · web-flow · commit 7d52491e1c80 · 2025-04-21T10:07:11.000-07:00
* Accept default value for Fn::FindInMap

* Support default value for Fn::FindInMap

* Update Changelog, prerelease

* 8.3.0
diff --git a/changelog.md b/changelog.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 8.3.0
+
+- Support a default value for cf.findInMap (Fn::FindInMap).
+
 ## 8.2.0
 
 - Add `LogRetentionInDays` option to Lambda shortcuts
diff --git a/lib/intrinsic.js b/lib/intrinsic.js
@@ -48,10 +48,16 @@ intrinsic.cidr = (ipBlock, count, cidrBits) => {
  * key-value pairs.
  * @param {string} attr - The second-level key name, which is set to one of the
  * keys from the list assigned to key.
+ * @param {string} defaultValue - The value that will resolve to if the key and/or attr can not be found from the mapping map.
+ * This field is optional and requires AWS::LanguageExtensions to be defined in the template.
  * @returns The value that is assigned to SecondLevelKey.
  */
-intrinsic.findInMap = (mapping, key, attr) => {
-  return { 'Fn::FindInMap': [mapping, key, attr] };
+intrinsic.findInMap = (mapping, key, attr, defaultValue) => {
+  const lookup = [mapping, key, attr];
+  if (defaultValue) {
+    lookup.push({ DefaultValue: defaultValue });
+  }
+  return { 'Fn::FindInMap': lookup };
 };
 
 /**
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mapbox/cloudfriend",
-  "version": "8.2.0",
+  "version": "8.3.0",
   "description": "Helper functions for assembling CloudFormation templates in JavaScript",
   "main": "index.js",
   "engines": {
@@ -11,6 +11,7 @@
     "lint": "eslint index.js test lib bin cloudformation",
     "lint:fix": "npm run lint -- --fix",
     "test": "nyc tape test/*.test.js | tap-spec",
+    "test:update": "UPDATE=1 npm run test",
     "coverage": "nyc --reporter html tape test/*.test.js && opener coverage/index.html",
     "build-ci-template": "bin/build-template.js cloudformation/ci.template.js > cloudformation/ci.template.json",
     "shortcuts-api-doc": "jsdoc2md lib/shortcuts/*.js > lib/shortcuts/api.md"
diff --git a/test/fixtures/shortcuts/hookshot-github-secret-ref.json b/test/fixtures/shortcuts/hookshot-github-secret-ref.json
@@ -28,7 +28,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -47,7 +47,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-github-secret-string.json b/test/fixtures/shortcuts/hookshot-github-secret-string.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-github.json b/test/fixtures/shortcuts/hookshot-github.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough-access-log-format.json b/test/fixtures/shortcuts/hookshot-passthrough-access-log-format.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -52,7 +52,7 @@
         }
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough-alarms.json b/test/fixtures/shortcuts/hookshot-passthrough-alarms.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough-enhanced-logging.json b/test/fixtures/shortcuts/hookshot-passthrough-enhanced-logging.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough-full-blown-logging.json b/test/fixtures/shortcuts/hookshot-passthrough-full-blown-logging.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough-logging.json b/test/fixtures/shortcuts/hookshot-passthrough-logging.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/hookshot-passthrough.json b/test/fixtures/shortcuts/hookshot-passthrough.json
@@ -24,7 +24,7 @@
       "Type": "AWS::ApiGateway::Stage",
       "Properties": {
         "DeploymentId": {
-          "Ref": "PassDeploymentac7cb6b9"
+          "Ref": "PassDeployment2a35d33e"
         },
         "StageName": "hookshot",
         "RestApiId": {
@@ -43,7 +43,7 @@
         ]
       }
     },
-    "PassDeploymentac7cb6b9": {
+    "PassDeployment2a35d33e": {
       "Type": "AWS::ApiGateway::Deployment",
       "DependsOn": "PassMethod",
       "Properties": {
diff --git a/test/fixtures/shortcuts/lambda-full.json b/test/fixtures/shortcuts/lambda-full.json
@@ -6,7 +6,10 @@
   "Mappings": {},
   "Conditions": {
     "Always": {
-      "Fn::Equals": ["1", "1"]
+      "Fn::Equals": [
+        "1",
+        "1"
+      ]
     }
   },
   "Resources": {
@@ -49,7 +52,9 @@
         "FunctionName": "my-function",
         "Handler": "index.something",
         "KmsKeyArn": "arn:aws:kms:us-east-1:123456789012:key/fake",
-        "Layers": ["arn:aws:fake:layer/abc"],
+        "Layers": [
+          "arn:aws:fake:layer/abc"
+        ],
         "MemorySize": 512,
         "ReservedConcurrentExecutions": 10,
         "Runtime": "nodejs18.x",
@@ -58,8 +63,12 @@
           "Mode": "Active"
         },
         "VpcConfig": {
-          "SecurityGroupIds": ["sg-12345"],
-          "SubnetIds": ["fake"]
+          "SecurityGroupIds": [
+            "sg-12345"
+          ],
+          "SubnetIds": [
+            "fake"
+          ]
         },
         "Tags": [
           {
@@ -68,7 +77,10 @@
           }
         ],
         "Role": {
-          "Fn::GetAtt": ["MyLambdaRole", "Arn"]
+          "Fn::GetAtt": [
+            "MyLambdaRole",
+            "Arn"
+          ]
         }
       }
     },
@@ -78,7 +90,9 @@
       "Properties": {
         "AlarmName": "my-alarm",
         "AlarmDescription": "some alarm",
-        "AlarmActions": ["devnull@mapbox.com"],
+        "AlarmActions": [
+          "devnull@mapbox.com"
+        ],
         "Period": 120,
         "EvaluationPeriods": 2,
         "DatapointsToAlarm": 1,
@@ -87,7 +101,9 @@
         "ComparisonOperator": "LessThanThreshold",
         "TreatMissingData": "breaching",
         "EvaluateLowSampleCountPercentile": "ignore",
-        "OKActions": ["devnull@mapbox.com"],
+        "OKActions": [
+          "devnull@mapbox.com"
+        ],
         "Namespace": "AWS/Lambda",
         "Dimensions": [
           {
@@ -118,7 +134,10 @@
               "Effect": "Allow",
               "Action": "logs:*",
               "Resource": {
-                "Fn::GetAtt": ["MyLambdaLogs", "Arn"]
+                "Fn::GetAtt": [
+                  "MyLambdaLogs",
+                  "Arn"
+                ]
               }
             }
           ]
@@ -161,4 +180,4 @@
     }
   },
   "Outputs": {}
-}
+}
diff --git a/test/fixtures/shortcuts/stream-lambda-no-defaults.json b/test/fixtures/shortcuts/stream-lambda-no-defaults.json
@@ -167,21 +167,21 @@
       "Properties": {
         "BatchSize": 10000,
         "MaximumBatchingWindowInSeconds": 300,
+        "Enabled": false,
+        "EventSourceArn": "arn:aws:kinesis:us-east-1:123456789012:stream/fake",
+        "FunctionName": {
+          "Ref": "MyLambda"
+        },
+        "StartingPosition": "TRIM_HORIZON",
         "FilterCriteria": {
           "Filters": [
             {
               "Pattern": "{\"eventName\":[\"INSERT\",\"MODIFY\"]}"
             }
           ]
-        },
-        "Enabled": false,
-        "EventSourceArn": "arn:aws:kinesis:us-east-1:123456789012:stream/fake",
-        "FunctionName": {
-          "Ref": "MyLambda"
-        },
-        "StartingPosition": "TRIM_HORIZON"
+        }
       }
     }
   },
   "Outputs": {}
-}
+}
diff --git a/test/index.test.js b/test/index.test.js
@@ -11,6 +11,7 @@ test('intrinsic functions', (assert) => {
   assert.deepEqual(cloudfriend.base64('secret'), { 'Fn::Base64': 'secret' }, 'base64');
   assert.deepEqual(cloudfriend.cidr('ipBlock', 1, 2), { 'Fn::Cidr': ['ipBlock', 1, 2] }, 'cidr');
   assert.deepEqual(cloudfriend.findInMap('mapping', 'key', 'value'), { 'Fn::FindInMap': ['mapping', 'key', 'value'] }, 'lookup');
+  assert.deepEqual(cloudfriend.findInMap('mapping', 'key', 'value', 'hello-world'), { 'Fn::FindInMap': ['mapping', 'key', 'value', { DefaultValue: 'hello-world' }] }, 'lookup with default value');
   assert.deepEqual(
     cloudfriend.forEach('somethings', 'topic', ['abra', 'cadabra'], 'magic', {
       Type: 'AWS::SNS::Topic',
