Merge pull request #1516 from snyk/fix/dont-create-json-if-you-dont-n…

…eed-it

Don't create JSON if we don't need it

src/cli/commands/test/formatters/format-test-results.ts

@@ -26,6 +26,7 @@ import { formatDockerBinariesIssues } from './docker';
 import { createSarifOutputForContainers } from '../sarif-output';
 import { createSarifOutputForIac } from '../iac-output';
 import { isNewVuln, isVulnFixable } from '../vuln-helpers';
+import { jsonStringifyLargeObject } from '../../../../lib/json';
 
 export function formatJsonOutput(jsonData) {
   const jsonDataClone = _.cloneDeep(jsonData);
@@ -46,29 +47,29 @@ export function extractDataToSendFromResults(
   options: Options,
 ): OutputDataTypes {
   let sarifData = {};
+  let stringifiedSarifData = '';
   if (options.sarif || options['sarif-file-output']) {
     sarifData = !options.iac
       ? createSarifOutputForContainers(results)
       : createSarifOutputForIac(results);
+    stringifiedSarifData = jsonStringifyLargeObject(sarifData);
   }
 
-  const stringifiedJsonData = JSON.stringify(
-    formatJsonOutput(jsonData),
-    null,
-    2,
-  );
-  const stringifiedSarifData = JSON.stringify(sarifData, null, 2);
+  let stringifiedJsonData = '';
+  if (options.json || options['json-file-output']) {
+    stringifiedJsonData = jsonStringifyLargeObject(formatJsonOutput(jsonData));
+  }
 
   const dataToSend = options.sarif ? sarifData : jsonData;
   const stringifiedData = options.sarif
     ? stringifiedSarifData
     : stringifiedJsonData;
 
   return {
-    stdout: dataToSend,
-    stringifiedData,
-    stringifiedJsonData,
-    stringifiedSarifData,
+    stdout: dataToSend, // this is for the human-readable stdout output and is set (but not used) even if --json or --sarif is set
+    stringifiedData, // this will be used to display either the Snyk or SARIF format JSON to stdout if --json or --sarif is set
+    stringifiedJsonData, // this will be used for the --json-file-output=<file.json> option
+    stringifiedSarifData, // this will be used for the --sarif-file-output=<file.json> option
   };
 }
 

src/lib/json.ts

@@ -0,0 +1,20 @@
+const debug = require('debug')('snyk-json');
+
+/**
+ * Attempt to json-stringify an object which is potentially very large and might exceed the string limit.
+ * If it does exceed the string limit, try again without pretty-print to hopefully come out below the string limit.
+ * @param obj the object from which you want to get a JSON string
+ */
+export function jsonStringifyLargeObject(obj: any): string {
+  let res = '';
+  try {
+    // first try pretty-print
+    res = JSON.stringify(obj, null, 2);
+    return res;
+  } catch (err) {
+    // if that doesn't work, try non-pretty print
+    debug('JSON.stringify failed - trying again without pretty print', err);
+    res = JSON.stringify(obj);
+    return res;
+  }
+}