IDEA-133425 Add simple test for JSON injection in Java string

json/tests/json-tests.iml

@@ -12,6 +12,6 @@
     <orderEntry type="module" module-name="json" scope="TEST" />
     <orderEntry type="module" module-name="testFramework-java" scope="TEST" />
     <orderEntry type="module" module-name="spellchecker" scope="TEST" />
+    <orderEntry type="module" module-name="codeInsight-tests" scope="TEST" />
   </component>
-</module>
-
+</module>

json/tests/test/com/intellij/json/JsonInjectionTest.java

@@ -0,0 +1,43 @@
+package com.intellij.json;
+
+import com.intellij.codeInsight.daemon.impl.HighlightInfo;
+import com.intellij.codeInsight.injected.InjectedLanguageTestCase;
+import com.intellij.codeInspection.LocalInspectionTool;
+import com.intellij.json.codeinsight.JsonStandardComplianceInspection;
+import com.intellij.lang.annotation.HighlightSeverity;
+import com.intellij.openapi.util.Condition;
+import com.intellij.testFramework.PlatformTestUtil;
+import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.util.List;
+
+/**
+ * @author Mikhail Golubev
+ */
+public class JsonInjectionTest extends InjectedLanguageTestCase {
+  // PY-133425
+  public void testJsonFragmentInjectedInJavaString() {
+    configureByFile("/injected/" + getTestName(false) + ".java");
+    final List<HighlightInfo> highlightInfos = doHighlighting(HighlightSeverity.WARNING);
+    assertNull(ContainerUtil.find(highlightInfos, new Condition<HighlightInfo>() {
+      @Override
+      public boolean value(HighlightInfo info) {
+        return info.getDescription().equals(JsonBundle.message("msg.compliance.problem.illegal.property.key"));
+      }
+    }));
+  }
+
+  @NotNull
+  @Override
+  protected LocalInspectionTool[] configureLocalInspectionTools() {
+    return new LocalInspectionTool[]{new JsonStandardComplianceInspection()};
+  }
+
+  @NotNull
+  @Override
+  protected String getTestDataPath() {
+    return PlatformTestUtil.getCommunityPath().replace(File.separatorChar, '/') + "/json/tests/testData";
+  }
+}

json/tests/testData/injected/JsonFragmentInjectedInJavaString.java

@@ -0,0 +1,4 @@
+class JsonFragmentInjectedInJavaString {
+  // language=JSON
+  String json = "{\"foo\": null}";
+}