vcs: new implementation for assertContainsOrdered

Previous implementation uses retainAll. It is not perfectly match the case if we want to check if elements which is exist in "collection" list contains in the same order in "expected" list.

platform/testFramework/src/com/intellij/testFramework/UsefulTestCase.java

@@ -31,6 +31,8 @@ import com.intellij.testFramework.exceptionCases.AbstractExceptionCase;
 import com.intellij.testFramework.fixtures.IdeaTestExecutionPolicy;
 import com.intellij.util.*;
 import com.intellij.util.containers.ContainerUtil;
+import com.intellij.util.containers.PeekableIterator;
+import com.intellij.util.containers.PeekableIteratorWrapper;
 import com.intellij.util.containers.hash.HashMap;
 import com.intellij.util.lang.CompoundRuntimeException;
 import com.intellij.util.ui.UIUtil;
@@ -43,6 +45,7 @@ import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.junit.Assert;
+import org.junit.ComparisonFailure;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -559,9 +562,20 @@ public abstract class UsefulTestCase extends TestCase {
   }
 
   public static <T> void assertContainsOrdered(@NotNull Collection<? extends T> collection, @NotNull Collection<? extends T> expected) {
-    ArrayList<T> copy = new ArrayList<>(collection);
-    copy.retainAll(expected);
-    assertOrderedEquals(toString(collection), copy, expected);
+    PeekableIterator<T> expectedIt = new PeekableIteratorWrapper<>(expected.iterator());
+    PeekableIterator<T> actualIt = new PeekableIteratorWrapper<>(collection.iterator());
+
+    while (actualIt.hasNext() && expectedIt.hasNext()) {
+      T expectedElem = expectedIt.peek();
+      T actualElem = actualIt.peek();
+      if (expectedElem.equals(actualElem)) {
+        expectedIt.next();
+      }
+      actualIt.next();
+    }
+    if (expectedIt.hasNext()) {
+      throw new ComparisonFailure("", toString(expected), toString(collection));
+    }
   }
 
   @SafeVarargs

plugins/git4idea/tests/git4idea/ignore/GitIgnoredFileTest.kt

@@ -4,12 +4,10 @@ package git4idea.ignore
 import com.intellij.openapi.command.WriteCommandAction
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.openapi.vfs.encoding.EncodingProjectManager
-import com.intellij.util.containers.PeekableIteratorWrapper
 import git4idea.GitUtil
 import git4idea.repo.GitRepositoryFiles.GITIGNORE
 import git4idea.test.GitPlatformTest
 import git4idea.test.createRepository
-import org.junit.Assert
 import java.io.File
 
 const val OUT = "out"
@@ -60,32 +58,7 @@ class GitIgnoredFileTest : GitPlatformTest() {
     val generatedGitIgnoreContent = gitIgnoreFile.readText(projectCharset)
     assertFalse("Generated ignore file is empty", generatedGitIgnoreContent.isBlank())
     assertFalse("Generated ignore file content should be system-independent", generatedGitIgnoreContent.contains('\\'))
-    assertIncludesAllOrdered(generatedGitIgnoreContent.lines(), gitIgnoreExpectedContentList)
-  }
-
-  private fun assertIncludesAllOrdered(actualList: List<String>, expectedList: List<String>) {
-    val expectedIt = PeekableIteratorWrapper(expectedList.iterator())
-    val actualIt = PeekableIteratorWrapper(actualList.iterator())
-
-    while (actualIt.hasNext() && expectedIt.hasNext()) {
-      val expected = expectedIt.peek()
-      val actual = actualIt.peek()
-      if (expected == actual) {
-        expectedIt.next()
-        actualIt.next()
-      }
-      else {
-        actualIt.next()
-      }
-    }
-
-    if(expectedIt.hasNext()){
-      Assert.fail("""
-         Expected: $expectedList
-         Actual: $actualList
-         Not included in the same order.
-      """.trimIndent())
-    }
+    assertContainsOrdered(generatedGitIgnoreContent.lines(), gitIgnoreExpectedContentList)
   }
 
   private fun VirtualFile.findOrCreateDir(dirName: String) = this.findChild(dirName) ?: createChildDirectory(this, dirName)