Allow to exclude specific qualified names from import in tests

In tests, ImportFix imports the first available candidate. This can
lead to non-deterministic tests when multiple candidates are available.
With this fix, unwanted candidates can be excluded.

idea/idea-test-framework/src/org/jetbrains/kotlin/idea/test/KotlinTestImportFilter.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.test
+
+import com.intellij.codeInsight.ImportFilter
+import com.intellij.openapi.application.ApplicationManager
+import com.intellij.psi.PsiFile
+import org.jetbrains.kotlin.test.InTextDirectivesUtils
+
+object KotlinTestImportFilter : ImportFilter() {
+    override fun shouldUseFullyQualifiedName(targetFile: PsiFile, classQualifiedName: String): Boolean {
+        if (!ApplicationManager.getApplication().isUnitTestMode) {
+            return false
+        }
+        val doNotImport = InTextDirectivesUtils.findLinesWithPrefixesRemoved(targetFile.text, "// DO_NOT_IMPORT:")
+        return classQualifiedName in doNotImport
+    }
+}