I'm still not able to get it work, still the same issue

I follow the SDK guide "Tests Prerequisites" http://www.jetbrains.org/intellij/sdk/docs/tutorials/writing_tests_for_plugins/tests_prerequisites.html and set the idea.home.path to point to my IJ

-ea
-Xbootclasspath/p:../out/classes/production/boot
-XX:+HeapDumpOnOutOfMemoryError
-Xmx512m
-XX:MaxPermSize=320m
-Didea.system.path=target/test-system
-Didea.config.path=target/test-config
-Didea.test.group=ALL_EXCLUDE_DEFINED
-Didea.load.plugins.id=org.apache.camel
-Didea.home.path="C:/Program Files (x86)/JetBrains/IntelliJ IDEA Community Edition 2016.3.2/"

it must point to checked out IJ community sources, not the installation

Thanks, I missed that part in your previous comment

It's works now :-)

The code news it's working for JDK classes now, but after that I got the same problem for 3 party libraries.

public void testAnnotatorCamelPredicateValidation() {
    myFixture.configureByText("AnnotatorTestData.java", getJavaWithCamelPredicate());
    myFixture.checkHighlighting(false, false, false, true);
}

private String getJavaWithCamelPredicate() {
 return "import org.apache.camel.builder.RouteBuilder;\n"
 + "public class MyRouteBuilder extends RouteBuilder {\n"
 + " public void configure() throws Exception {\n"
 + " from(\"direct:start\")\n"
 + " .loopDoWhile(simple(\"${body.length} <error descr=\"Unexpected token !\">=!=</error> 12\"))\n"
 + " .to(\"mock:loop\")\n"
 + " .transform(body().append(\"A\"))\n"
 + " .end()\n"
 + " .to(\"mock:result\");"
 + " }\n"
 + " }";
}

I have added the camel-core lib to myModule, but it still fail with "Cannot resolve symbol" for Apache Camel classes

import <error descr="Cannot resolve symbol 'org'">org</error>.apache.camel.builder.RouteBuilder;
public class MyRouteBuilder extends <error descr="Cannot resolve symbol 'RouteBuilder'">RouteBuilder</error> {
 public void configure() throws <error descr="Cannot resolve symbol 'Exception'">Exception</error> {
 <error descr="Cannot resolve method 'from(java.lang.String)'">from</error>("direct:start")
 .loopDoWhile(<error descr="Cannot resolve method 'simple(java.lang.String)'">simple</error>("${body.length} =!= 12"))
 .to("mock:loop")
 .transform(<error descr="Cannot resolve method 'body()'">body</error>().append("A"))
 .end()
 .to("mock:result"); }
 }

File[] mavenArtifacts = getMavenArtifacts(CAMEL_CORE_MAVEN_ARTIFACT);
VirtualFile virtualFile = LocalFileSystem.getInstance().refreshAndFindFileByIoFile(mavenArtifacts[0]);
PsiTestUtil.addProjectLibrary(myModule, "Maven: " + CAMEL_CORE_MAVEN_ARTIFACT, virtualFile);
final LibraryTable projectLibraryTable = LibraryTablesRegistrar.getInstance().getLibraryTable(myModule.getProject());

ApplicationManager.getApplication().runWriteAction(() -> {
    Library library = projectLibraryTable.createLibrary("Maven: " + CAMEL_CORE_MAVEN_ARTIFACT);
    final Library.ModifiableModel libraryModifiableModel = library.getModifiableModel();
    libraryModifiableModel.addRoot(virtualFile, OrderRootType.CLASSES);
    libraryModifiableModel.commit();
    ModuleRootModificationUtil.addDependency(myModule, library);
});

How do you make it aware of 3 party libs in my test?

Thanks

Please use com.intellij.testFramework.PsiTestUtil to add libraries and perform other test project modifications.

Thanks!!!!

With the insight your provided, I was able to solve it by adding the library in the "getProjectDescription" method

@Override
protected LightProjectDescriptor getProjectDescriptor() {

    return new DefaultLightProjectDescriptor() {
        @Override
        public void configureModule(@NotNull Module module, @NotNull ModifiableRootModel model, @NotNull ContentEntry contentEntry) {
            super.configureModule(module, model, contentEntry);
            File[] mavenArtifacts;
            try {
                mavenArtifacts = getMavenArtifacts(CAMEL_CORE_MAVEN_ARTIFACT);
                PsiTestUtil.addLibrary(module, model, "Maven: " + CAMEL_CORE_MAVEN_ARTIFACT, mavenArtifacts[0].getParent(), mavenArtifacts[0].getName());
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    };
}