Move plain text-specific part of EnterActionTest to platform-tests module

GitOrigin-RevId: 732eae92ffc94e0c792f7b263ffe0415cdeb0225

platform/platform-tests/testData/codeInsight/enterAction/EnterInTextFile.txt

@@ -0,0 +1,4 @@
+text text text
+   text text text<caret>
+ text text
+text tetetetetet

platform/platform-tests/testData/codeInsight/enterAction/EnterInTextFile_after.txt

@@ -0,0 +1,5 @@
+text text text
+   text text text
+   <caret>
+ text text
+text tetetetetet

platform/platform-tests/testSrc/com/intellij/codeInsight/PlainTextEnterActionTest.java

@@ -0,0 +1,52 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.codeInsight;
+
+import com.intellij.testFramework.PlatformTestUtil;
+import org.jetbrains.annotations.NotNull;
+
+public class PlainTextEnterActionTest extends AbstractEnterActionTestCase {
+  @NotNull
+  @Override
+  protected String getTestDataPath() {
+    return PlatformTestUtil.getPlatformTestDataPath();
+  }
+
+  public void testEnterInTextFile() throws Exception {
+    doTest("txt");
+  }
+
+  public void testEnterWithSpacesAfterCaret() {
+    doTextTest("txt", "abc <caret> ", "abc \n<caret> ");
+  }
+
+  public void testSCR2236() {
+    doTextTest("txt", "//file/text/<caret>text/text", "//file/text/\n" + "<caret>text/text");
+  }
+
+  public void testUnmatchedBraceAtPlainTextFile() {
+    // Inspired by IDEA-64060
+    doTextTest(
+      "txt",
+      "   class Foo {<caret>",
+      "   class Foo {\n" +
+      "   <caret>\n" +
+      "   }"
+    );
+  }
+
+  public void testInJavaDocLikeStringOfPlainTextFile() {
+    // Inspired by IDEA-65108
+    doTextTest(
+      "txt",
+      "Here is a list of bullet points:\n" +
+      "* Bullet one.  <caret>Bullet two.",
+      "Here is a list of bullet points:\n" +
+      "* Bullet one.  \n" +
+      "<caret>Bullet two."
+    );
+  }
+
+  public void testIndentCalculationWithTabsInIndent() {
+    doTextTest("txt", "\t<caret>\tabc", "\t\n\t<caret>\tabc");
+  }
+}