IDEA-167088 Stream API migration: support joining with delimiter

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/afterJoiningDelimited.java

@@ -0,0 +1,19 @@
+// "Replace with collect" "true"
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Test {
+  static String test(List<String> list) {
+    String sb = "";
+    if (!list.isEmpty()) {
+        sb = list.stream().filter(s -> !s.isEmpty()).map(s -> String.valueOf(s.length())).collect(Collectors.joining("\""));
+    }
+    return sb.trim();
+  }
+
+  public static void main(String[] args) {
+    System.out.println(test(Arrays.asList("abc", "", "xyz", "argh")));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeJoiningDelimited.java

@@ -0,0 +1,25 @@
+// "Replace with collect" "true"
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Test {
+  static String test(List<String> list) {
+    StringBuilder sb = new StringBuilder();
+    if (!list.isEmpty()) {
+      for (String s : li<caret>st) {
+        if (!s.isEmpty()) {
+          if (sb.length() > 0) {
+            sb.append('"');
+          }
+          sb.append(s.length());
+        }
+      }
+    }
+    return sb.toString().trim();
+  }
+
+  public static void main(String[] args) {
+    System.out.println(test(Arrays.asList("abc", "", "xyz", "argh")));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeJoiningDelimitedWrongBuilder.java

@@ -0,0 +1,26 @@
+// "Replace with collect" "false"
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Test {
+  static String test(List<String> list) {
+    StringBuilder sb = new StringBuilder();
+    StringBuilder sb2 = new StringBuilder();
+    if (!list.isEmpty()) {
+      for (String s : li<caret>st) {
+        if (!s.isEmpty()) {
+          if (sb2.length() > 0) {
+            sb.append('"');
+          }
+          sb.append(s.length());
+        }
+      }
+    }
+    return sb.toString().trim();
+  }
+
+  public static void main(String[] args) {
+    System.out.println(test(Arrays.asList("abc", "", "xyz", "argh")));
+  }
+}