test: use json stream parser in existing test

package.json

@@ -156,12 +156,13 @@
     "depcheck": "^1.4.3",
     "eslint": "6.8.0",
     "eslint-config-prettier": "^6.1.0",
-    "jest-junit": "^16.0.0",
     "eslint-plugin-anti-trojan-source": "^1.1.1",
     "eslint-plugin-jest": "^24.4.0",
     "express": "^4.17.1",
     "fs-extra": "^9.1.0",
     "jest": "^28.1.3",
+    "jest-junit": "^16.0.0",
+    "jsonparse": "^1.3.1",
     "lodash": "^4.17.20",
     "mock-fs": "^4.13.0",
     "node-loader": "^2.0.0",

test/jest/acceptance/cli-json-output.spec.ts

@@ -101,33 +101,23 @@ describe('test --json', () => {
         },
       );
 
-      // check for these properties in the buffer chunks
-      const pathString = `"path": "${imageName}"`;
+      if (stderrBuffer && stderrBuffer.length > 0)
+        console.log(stderrBuffer?.toString('utf8'));
+
       let hasExpectedPathString = false;
-      const vulnerabilitiesString = `"vulnerabilities": [`;
       let hasExpectedVulnerabilitiesString = false;
 
-      const chunkSize = 1024 * 1024 * 450; // 450 MB
-      if (stdoutBuffer) {
-        for (let i = 0; i < stdoutBuffer.length; i += chunkSize) {
-          const chunk = stdoutBuffer.slice(
-            i,
-            Math.min(i + chunkSize, stdoutBuffer.length),
-          );
-
-          if (!hasExpectedVulnerabilitiesString) {
-            hasExpectedVulnerabilitiesString = chunk
-              .toString('utf8')
-              .includes(vulnerabilitiesString);
-          }
-
-          if (!hasExpectedPathString) {
-            hasExpectedPathString = chunk.toString('utf8').includes(pathString);
-          }
+      const Parser = require('jsonparse');
+      const p = new Parser();
+      p.onValue = function(value) {
+        if (this.key === 'path' && value === imageName) {
+          hasExpectedPathString = true;
+        } else if (this.key === 'vulnerabilities') {
+          hasExpectedVulnerabilitiesString = true;
         }
-      }
+      };
 
-      if (stderrBuffer) console.log(stderrBuffer.toString('utf8'));
+      p.write(stdoutBuffer);
 
       expect(code).toEqual(1);
       expect(hasExpectedVulnerabilitiesString).toBeTruthy();