run npm install and link once before tests

.travis.yml

@@ -218,7 +218,7 @@ before_install:
 script:
   - |
     cd runtime-testsuite;
-    travis_wait 4 ../.travis/run-tests-$TARGET.sh;
-    rc=$?;
-    cat target/surefire-reports/*.dumpstream || true;
+    travis_wait 4 ../.travis/run-tests-$TARGET.sh
+    rc=$?
+    cat target/surefire-reports/*.dumpstream || true
     exit $rc

.travis/run-tests-javascript.sh

@@ -2,4 +2,8 @@
 
 set -euo pipefail
 
+cd ../runtime/JavaScript
+npm install
+npm link
+cd ../../runtime-testsuite
 mvn -q -Dparallel=methods -DthreadCount=1 -Dtest=javascript.* test

runtime-testsuite/test/org/antlr/v4/test/runtime/javascript/BaseNodeTest.java

@@ -268,8 +268,8 @@ public class BaseNodeTest implements RuntimeTestSupport {
 	public String execModule(String fileName) {
 		try {
 			String npmPath = locateNpm();
-			installRuntime(npmPath);
-			registerRuntime(npmPath);
+			// installRuntime(npmPath);
+			// registerRuntime(npmPath);
 			String modulePath = new File(new File(tmpdir), fileName)
 					.getAbsolutePath();
 			linkRuntime(npmPath);