Fix: readded missing should not duplicate fingerprint entries test

Author: Stefan-Gabriel Muscalu

test/internal/tls.test.js

@@ -180,6 +180,60 @@ describe('trust-on-first-use', function() {
       done();
     });
   });
+
+  it('should not duplicate fingerprint entries', function(done) {
+    // Assuming we only run this test on NodeJS with TOFU support
+    if( !hasFeature("trust_on_first_use") ) {
+      done();
+      return;
+    }
+
+    // Given
+    var knownHostsPath = "build/known_hosts";
+    if( fs.existsSync(knownHostsPath) ) {
+      fs.unlinkSync(knownHostsPath);
+    }
+    fs.writeFileSync(knownHostsPath, '');
+
+    driver = neo4j.driver("bolt://localhost", neo4j.auth.basic("neo4j", "neo4j"), {
+      encrypted: true,
+      trust: "TRUST_ON_FIRST_USE",
+      knownHosts: knownHostsPath
+    });
+
+    // When
+    driver.session();
+    driver.session();
+
+    // Then
+    setTimeout(function() {
+      var lines = {};
+      fs.readFileSync(knownHostsPath, 'utf8')
+          .split('\n')
+          .filter(function(line) {
+            return !! (line.trim());
+          })
+          .forEach(function(line) {
+            if (!lines[line]) {
+              lines[line] = 0;
+            }
+            lines[line]++;
+          });
+
+      var duplicatedLines = Object
+          .keys(lines)
+          .map(function(line) {
+            return lines[line];
+          })
+          .filter(function(count) {
+            return count > 1;
+          })
+          .length;
+
+      expect( duplicatedLines ).toBe( 0 );
+      done();
+    }, 1000);
+  });
 
   it('should should give helpful error if database cert does not match stored certificate', function(done) {
     // Assuming we only run this test on NodeJS with TOFU support