DiamondOperatorForVariableDefinitionCheck false negatives

[romani]

Force Diamond check missed following cases: https://github.com/checkstyle/checkstyle/commit/1395a92adb0d8fd0767bee81dc407c5e58b37252

Check: https://github.com/sevntu-checkstyle/sevntu.checkstyle/blob/master/sevntu-checks/src/main/java/com/github/sevntu/checkstyle/checks/coding/DiamondOperatorForVariableDefinitionCheck.java

[scop]

Not sure if it's the same issue, but it also misses cases like:

HashMap<String, String> foo;
foo = new HashMap<String, String>();

[rnveach]

Current check is only looking at VARIABLE_DEF and it looks like it needs to look at LITERAL_NEW too. It probably should follow variable declarations and scope similar to RequireThisCheck.

One issue with:

-        this(new HashMap<String, String>(1));
+        this(new HashMap<>(1));

We can't tell if the method parameter is missing type or has wildcard type. This may be a limitation of the check if method/constructor is declared in another file.

[romani]

This may be a limitation of the check

this is limitation of the whole checkstyle. Check should skip such cases from validation.