Java8MapApiInspection: support some scenarios to produce Map.merge (IDEA-163910)

java/java-tests/testData/inspection/java8MapApi/afterComputeIfAbsentVarUnused.java

@@ -4,7 +4,6 @@ import java.util.Map;
 public class Main {
 
   public void test(Map<String, List<String>> map, String key) {
-    List<String> list = map.get(key);
       map.computeIfAbsent(key, k -> new ArrayList<>());
     System.out.println(map);
   }

java/java-tests/testData/inspection/java8MapApi/afterMergeMethod.java

@@ -0,0 +1,11 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+    public void testMerge(Map<String, Integer> map, String key, int max) {
+        /*get!*/
+        // check
+        /*get max*/
+        map.merge(key, /* passed max value */ max, Math::max)
+    }
+}

java/java-tests/testData/inspection/java8MapApi/afterMergeSimple.java

@@ -0,0 +1,8 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key) {
+      map.merge(key, 1, (a, b) -> a + b)
+  }
+}

java/java-tests/testData/inspection/java8MapApi/afterMergeVariable.java

@@ -0,0 +1,8 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key) {
+      map.merge(key, 1, (a, b) -> b + a)
+  }
+}

java/java-tests/testData/inspection/java8MapApi/afterMergeVariableUsed.java

@@ -0,0 +1,10 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key, int add) {
+    Integer val = map.get(key);
+      map.merge(key, add, (a, b) -> b + a)
+    System.out.println(val);
+  }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeMethod.java

@@ -0,0 +1,14 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+    public void testMerge(Map<String, Integer> map, String key, int max) {
+        Integer val = /*get!*/map.get(key);
+        // check
+        if(val<caret> == null) {
+            map.put(key, /* passed max value */ max)
+        } else {
+            map.put(key, Math.max(/*get max*/val, max));
+        }
+    }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeMismatch.java

@@ -0,0 +1,14 @@
+// "Replace with 'merge' method call" "false"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key, int add) {
+    Integer val = map.get(key);
+    if(val<caret> == null) {
+      map.put(key, add + val);
+    } else {
+      map.put(key, add)
+    }
+    System.out.println(val);
+  }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeMismatch2.java

@@ -0,0 +1,14 @@
+// "Replace with 'merge' method call" "false"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key, int add) {
+    Integer val = map.get(key);
+    if(val<caret> == null) {
+      map.put(key, add);
+    } else {
+      map.put(key, add + 1)
+    }
+    System.out.println(val);
+  }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeSimple.java

@@ -0,0 +1,12 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key) {
+    if(map.get(key)<caret> == null) {
+      map.put(key, 1)
+    } else {
+      map.put(key, map.get(key) + 1);
+    }
+  }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeVariable.java

@@ -0,0 +1,13 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key) {
+    Integer val = map.get(key);
+    if(val<caret> == null) {
+      map.put(key, 1)
+    } else {
+      map.put(key, 1 + val);
+    }
+  }
+}

java/java-tests/testData/inspection/java8MapApi/beforeMergeVariableUsed.java

@@ -0,0 +1,14 @@
+// "Replace with 'merge' method call" "true"
+import java.util.Map;
+
+public class Main {
+  public void testMerge(Map<String, Integer> map, String key, int add) {
+    Integer val = map.get(key);
+    if(val<caret> == null) {
+      map.put(key, add)
+    } else {
+      map.put(key, add + val);
+    }
+    System.out.println(val);
+  }
+}