IDEA-161257 Add Java-8 migration fix to use Map.computeIfAbsent where appropriate

java/java-tests/testData/inspection/java8CollectionsApi/afterComputeIfAbsent.java

@@ -0,0 +1,11 @@
+// "Replace with 'computeIfAbsent' method call" "true"
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class Main {
+  public void testMap(Map<String, List<String>> map, String key, String value) {
+    List<String> list = map.computeIfAbsent(key, k -> new ArrayList<>());
+      list.add(value);
+  }
+}

java/java-tests/testData/inspection/java8CollectionsApi/afterComputeIfAbsentVarConflict.java

@@ -0,0 +1,13 @@
+// "Replace with 'computeIfAbsent' method call" "true"
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class Main {
+  String k;
+
+  public void testMap(Map<String, List<String>> map, String value) {
+    List<String> list = map.computeIfAbsent(this.k, k1 -> new ArrayList<>());
+      list.add(value);
+  }
+}

java/java-tests/testData/inspection/java8CollectionsApi/beforeComputeIfAbsent.java

@@ -0,0 +1,15 @@
+// "Replace with 'computeIfAbsent' method call" "true"
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class Main {
+  public void testMap(Map<String, List<String>> map, String key, String value) {
+    List<String> list = map.get(key);
+    if(list == nul<caret>l) {
+      list = new ArrayList<>();
+      map.put(key, list);
+    }
+    list.add(value);
+  }
+}

java/java-tests/testData/inspection/java8CollectionsApi/beforeComputeIfAbsentNonFinal.java

@@ -0,0 +1,17 @@
+// "Replace with 'computeIfAbsent' method call" "false"
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class Main {
+  public void testMap(Map<String, List<String>> map, String key, String value) {
+    int size = 5;
+    if(map.isEmpty()) size = 10;
+    List<String> list = map.get(key);
+    if(list == <caret>null) {
+      list = new ArrayList<>(size);
+      map.put(key, list);
+    }
+    list.add(value);
+  }
+}

java/java-tests/testData/inspection/java8CollectionsApi/beforeComputeIfAbsentVarConflict.java

@@ -0,0 +1,17 @@
+// "Replace with 'computeIfAbsent' method call" "true"
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class Main {
+  String k;
+
+  public void testMap(Map<String, List<String>> map, String value) {
+    List<String> list = map.get(this.k);
+    if(list == nul<caret>l) {
+      list = new ArrayList<>();
+      map.put(this.k, list);
+    }
+    list.add(value);
+  }
+}

java/java-tests/testData/inspection/java8CollectionsApi/beforeGetOrDefaultAssignment.java

@@ -6,8 +6,8 @@ public class Main {
   public void testGetOrDefault(Map<String, String> map, String key) {
     Integer num = 123;
     System.out.println(num);
-    num = map.get(k<caret>ey);
-    if(num == null) num = 0;
+    num = map.get(key);
+    if(num == nu<caret>ll) num = 0;
     System.out.println(num);
   }
 }

java/java-tests/testData/inspection/java8CollectionsApi/beforeGetOrDefaultField.java

@@ -7,8 +7,8 @@ public class Main {
   private String str;
 
   public void testGetOrDefault(Map<String, String> map, String key, Main other) {
-    str = map.get(k<caret>ey);
-    if(str == null) {
+    str = map.get(key);
+    if(str == nul<caret>l) {
       /*
       block comment
        */

java/java-tests/testData/inspection/java8CollectionsApi/beforeGetOrDefaultFieldOther.java

@@ -5,8 +5,8 @@ public class Main {
   private String str;
 
   public void testGetOrDefault(Map<String, String> map, String key, Main other) {
-    str = map.get(k<caret>ey);
-    if(other.str == null) {
+    str = map.get(key);
+    if(other.str ==<caret> null) {
       // comment
       str = "";
     }

java/java-tests/testData/inspection/java8CollectionsApi/beforeGetOrDefaultFieldOther2.java

@@ -5,8 +5,8 @@ public class Main {
   private String str;
 
   public void testGetOrDefault(Map<String, String> map, String key, Main other) {
-    str = map.get(k<caret>ey);
-    if(str == null) {
+    str = map.get(key);
+    if(s<caret>tr == null) {
       // comment
       other.str = "";
     }

java/java-tests/testData/inspection/java8CollectionsApi/beforeGetOrDefaultLocal.java

@@ -4,8 +4,8 @@ import java.util.Map;
 public class Main {
 
   public void testGetOrDefault(Map<String, String> map, String key, Main other) {
-    String a = null, str = map.get(k<caret>ey);
-    if(str == null) {
+    String a = null, str = map.get(key);
+    if(str == nu<caret>ll) {
       // comment
       str = "";
     }