Make EcrScanEvent severities optional (#783)

* Make EcrScanEvent severities optional

* Add the ecr example json file needed by test

Author: RafalSumislawski

lambda-events/src/event/ecr_scan/mod.rs

@@ -43,18 +43,24 @@ pub struct EcrScanEventDetailType {
 #[derive(Debug, Clone, Eq, PartialEq, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct EcrScanEventFindingSeverityCounts {
+    #[serde(default)]
     #[serde(rename = "CRITICAL")]
-    pub critical: i64,
+    pub critical: Option<i64>,
+    #[serde(default)]
     #[serde(rename = "HIGH")]
-    pub high: i64,
+    pub high: Option<i64>,
+    #[serde(default)]
     #[serde(rename = "MEDIUM")]
-    pub medium: i64,
+    pub medium: Option<i64>,
+    #[serde(default)]
     #[serde(rename = "LOW")]
-    pub low: i64,
+    pub low: Option<i64>,
+    #[serde(default)]
     #[serde(rename = "INFORMATIONAL")]
-    pub informational: i64,
+    pub informational: Option<i64>,
+    #[serde(default)]
     #[serde(rename = "UNDEFINED")]
-    pub undefined: i64,
+    pub undefined: Option<i64>,
 }
 
 #[cfg(test)]
@@ -70,4 +76,14 @@ mod test {
         let reparsed: EcrScanEvent = serde_json::from_slice(output.as_bytes()).unwrap();
         assert_eq!(parsed, reparsed);
     }
+
+    #[test]
+    #[cfg(feature = "ecr_scan")]
+    fn example_ecr_image_scan_event_with_missing_severities() {
+        let data = include_bytes!("../../fixtures/example-ecr-image-scan-event-with-missing-severities.json");
+        let parsed: EcrScanEvent = serde_json::from_slice(data).unwrap();
+        let output: String = serde_json::to_string(&parsed).unwrap();
+        let reparsed: EcrScanEvent = serde_json::from_slice(output.as_bytes()).unwrap();
+        assert_eq!(parsed, reparsed);
+    }
 }

lambda-events/src/fixtures/example-ecr-image-scan-event-with-missing-severities.json

@@ -0,0 +1,22 @@
+{
+    "version": "0",
+    "id": "85fc3613-e913-7fc4-a80c-a3753e4aa9ae",
+    "detail-type": "ECR Image Scan",
+    "source": "aws.ecr",
+    "account": "123456789012",
+    "time": "2019-10-29T02:36:48Z",
+    "region": "us-east-1",
+    "resources": [
+        "arn:aws:ecr:us-east-1:123456789012:repository/my-repository-name"
+    ],
+    "detail": {
+        "scan-status": "COMPLETE",
+        "repository-name": "my-repository-name",
+        "finding-severity-counts": {
+	       "CRITICAL": 10,
+	       "MEDIUM": 9
+	     },
+        "image-digest": "sha256:7f5b2640fe6fb4f46592dfd3410c4a79dac4f89e4782432e0378abcd1234",
+        "image-tags": []
+    }
+}