Array declarator bracket placement in TYPE_ARGUMENTS AST is incorrect

[nrmancuso]

➜  src javac Test.java

➜  src cat Test.java
import java.lang.reflect.TypeVariable;

public class Test {
    public TypeVariable<Class<String>>[] getTypeParameters() {
        return null;
    }
}

➜  src java -jar checkstyle-8.43-all.jar -t Test.javav
Files to process must be specified, found 0.

➜  src java -jar checkstyle-8.44-SNAPSHOT-all.jar -t Test.java 
IMPORT -> import [1:0]
|--DOT -> . [1:24]
|   |--DOT -> . [1:16]
|   |   |--DOT -> . [1:11]
|   |   |   |--IDENT -> java [1:7]
|   |   |   `--IDENT -> lang [1:12]
|   |   `--IDENT -> reflect [1:17]
|   `--IDENT -> TypeVariable [1:25]
`--SEMI -> ; [1:37]
CLASS_DEF -> CLASS_DEF [3:0]
|--MODIFIERS -> MODIFIERS [3:0]
|   `--LITERAL_PUBLIC -> public [3:0]
|--LITERAL_CLASS -> class [3:7]
|--IDENT -> Test [3:13]
`--OBJBLOCK -> OBJBLOCK [3:18]
    |--LCURLY -> { [3:18]
    |--METHOD_DEF -> METHOD_DEF [4:4]
    |   |--MODIFIERS -> MODIFIERS [4:4]
    |   |   `--LITERAL_PUBLIC -> public [4:4]
    |   |--TYPE -> TYPE [4:11]
    |   |   |--IDENT -> TypeVariable [4:11]
    |   |   `--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:23]
    |   |       |--GENERIC_START -> < [4:23]
    |   |       |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:24]
    |   |       |   |--IDENT -> Class [4:24]
    |   |       |   |--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:29]
    |   |       |   |   |--GENERIC_START -> < [4:29]
    |   |       |   |   |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:30]
    |   |       |   |   |   |--IDENT -> String [4:30]
    |   |       |   |   |   `--ARRAY_DECLARATOR -> [ [4:36] // Correct
    |   |       |   |   |       `--RBRACK -> ] [4:37]
    |   |       |   |   `--GENERIC_END -> > [4:38]
    |   |       |   `--ARRAY_DECLARATOR -> [ [4:40] // Incorrect
    |   |       |       `--RBRACK -> ] [4:41]
    |   |       `--GENERIC_END -> > [4:39]
    |   |--IDENT -> getTypeParameters [4:43]
    |   |--LPAREN -> ( [4:60]
    |   |--PARAMETERS -> PARAMETERS [4:61]
    |   |--RPAREN -> ) [4:61]
    |   `--SLIST -> { [4:63]
    |       |--LITERAL_RETURN -> return [5:8]
    |       |   |--EXPR -> EXPR [5:15]
    |       |   |   `--LITERAL_NULL -> null [5:15]
    |       |   `--SEMI -> ; [5:19]
    |       `--RCURLY -> } [6:4]
    `--RCURLY -> } [7:0]

The [] that follow the type arguments of the getTypeParameters() method are part of the return type of the method itself, and should be located in the method declaration's TYPE subtree.
Example:

IMPORT -> import [1:0]
|--DOT -> . [1:24]
|   |--DOT -> . [1:16]
|   |   |--DOT -> . [1:11]
|   |   |   |--IDENT -> java [1:7]
|   |   |   `--IDENT -> lang [1:12]
|   |   `--IDENT -> reflect [1:17]
|   `--IDENT -> TypeVariable [1:25]
`--SEMI -> ; [1:37]
CLASS_DEF -> CLASS_DEF [3:0]
|--MODIFIERS -> MODIFIERS [3:0]
|   `--LITERAL_PUBLIC -> public [3:0]
|--LITERAL_CLASS -> class [3:7]
|--IDENT -> Test [3:13]
`--OBJBLOCK -> OBJBLOCK [3:18]
    |--LCURLY -> { [3:18]
    |--METHOD_DEF -> METHOD_DEF [4:4]
    |   |--MODIFIERS -> MODIFIERS [4:4]
    |   |   `--LITERAL_PUBLIC -> public [4:4]
    |   |--TYPE -> TYPE [4:11]
    |   |   |--IDENT -> TypeVariable [4:11]
    |   |   |--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:23]
    |   |   |   |--GENERIC_START -> < [4:23]
    |   |   |   |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:24]
    |   |   |   |   |--IDENT -> Class [4:24]
    |   |   |   |   `--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:29]
    |   |   |   |       |--GENERIC_START -> < [4:29]
    |   |   |   |       |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:30]
    |   |   |   |       |   |--IDENT -> String [4:30]
    |   |   |   |       |   `--ARRAY_DECLARATOR -> [ [4:36] // Correct
    |   |   |   |       |       `--RBRACK -> ] [4:37]
    |   |   |   |       `--GENERIC_END -> > [4:38]
    |   |   |   `--GENERIC_END -> > [4:39]
    |   |   `--ARRAY_DECLARATOR -> [ [4:40]     // Correct
    |   |       `--RBRACK -> ] [4:41]             
    |   |--IDENT -> getTypeParameters [4:43]
    |   |--LPAREN -> ( [4:60]
    |   |--PARAMETERS -> PARAMETERS [4:61]
    |   |--RPAREN -> ) [4:61]
    |   `--SLIST -> { [4:63]
    |       |--LITERAL_RETURN -> return [5:8]
    |       |   |--EXPR -> EXPR [5:15]
    |       |   |   `--LITERAL_NULL -> null [5:15]
    |       |   `--SEMI -> ; [5:19]
    |       `--RCURLY -> } [6:4]
    `--RCURLY -> } [7:0]

[pbludov]

This is a bug. Such tree should be created for something like

    public TypeVariable<Class<String>[]> getTypeParameters()

interesting that for

    public TypeVariable<Class<String[]>[]>[] getTypeParameters()

the AST is correct:

    |--METHOD_DEF -> METHOD_DEF [4:4]
    |   |--MODIFIERS -> MODIFIERS [4:4]
    |   |   |--LITERAL_PUBLIC -> public [4:4]
    |   |   `--ABSTRACT -> abstract [4:11]
    |   |--TYPE -> TYPE [4:20]
    |   |   |--IDENT -> TypeVariable [4:20]
    |   |   |--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:32]
    |   |   |   |--GENERIC_START -> < [4:32]
    |   |   |   |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:33]
    |   |   |   |   |--IDENT -> Class [4:33]
    |   |   |   |   |--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:38]
    |   |   |   |   |   |--GENERIC_START -> < [4:38]
    |   |   |   |   |   |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:39]
    |   |   |   |   |   |   |--IDENT -> String [4:39]
    |   |   |   |   |   |   `--ARRAY_DECLARATOR -> [ [4:45]
    |   |   |   |   |   |       `--RBRACK -> ] [4:46]
    |   |   |   |   |   `--GENERIC_END -> > [4:47]
    |   |   |   |   `--ARRAY_DECLARATOR -> [ [4:48]
    |   |   |   |       `--RBRACK -> ] [4:49]
    |   |   |   `--GENERIC_END -> > [4:50]
    |   |   `--ARRAY_DECLARATOR -> [ [4:51]
    |   |       `--RBRACK -> ] [4:52]
    |   |--IDENT -> getTypeParameters [4:54]
    |   |--LPAREN -> ( [4:71]
    |   |--PARAMETERS -> PARAMETERS [4:72]
    |   |--RPAREN -> ) [4:72]

[nrmancuso]

Fixed via #10280:

 ➜  src cat Test.java
import java.lang.reflect.TypeVariable;

public class Test {
    public TypeVariable<Class<String>>[] getTypeParameters() {
        return null;
    }
}

➜  src java -jar ~/IdeaProjects/checkstyle/target/checkstyle-9.0-SNAPSHOT-all.jar -t Test.java
IMPORT -> import [1:0]
|--DOT -> . [1:24]
|   |--DOT -> . [1:16]
|   |   |--DOT -> . [1:11]
|   |   |   |--IDENT -> java [1:7]
|   |   |   `--IDENT -> lang [1:12]
|   |   `--IDENT -> reflect [1:17]
|   `--IDENT -> TypeVariable [1:25]
`--SEMI -> ; [1:37]
CLASS_DEF -> CLASS_DEF [3:0]
|--MODIFIERS -> MODIFIERS [3:0]
|   `--LITERAL_PUBLIC -> public [3:0]
|--LITERAL_CLASS -> class [3:7]
|--IDENT -> Test [3:13]
`--OBJBLOCK -> OBJBLOCK [3:18]
    |--LCURLY -> { [3:18]
    |--METHOD_DEF -> METHOD_DEF [4:4]
    |   |--MODIFIERS -> MODIFIERS [4:4]
    |   |   `--LITERAL_PUBLIC -> public [4:4]
    |   |--TYPE -> TYPE [4:11]
    |   |   |--IDENT -> TypeVariable [4:11]
    |   |   |--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:23]
    |   |   |   |--GENERIC_START -> < [4:23]
    |   |   |   |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:24]
    |   |   |   |   |--IDENT -> Class [4:24]
    |   |   |   |   `--TYPE_ARGUMENTS -> TYPE_ARGUMENTS [4:29]
    |   |   |   |       |--GENERIC_START -> < [4:29]
    |   |   |   |       |--TYPE_ARGUMENT -> TYPE_ARGUMENT [4:30]
    |   |   |   |       |   `--IDENT -> String [4:30]
    |   |   |   |       `--GENERIC_END -> > [4:36]
    |   |   |   `--GENERIC_END -> > [4:37]
    |   |   `--ARRAY_DECLARATOR -> [ [4:38]
    |   |       `--RBRACK -> ] [4:39]
    |   |--IDENT -> getTypeParameters [4:41]
    |   |--LPAREN -> ( [4:58]
    |   |--PARAMETERS -> PARAMETERS [4:59]
    |   |--RPAREN -> ) [4:59]
    |   `--SLIST -> { [4:61]
    |       |--LITERAL_RETURN -> return [5:8]
    |       |   |--EXPR -> EXPR [5:15]
    |       |   |   `--LITERAL_NULL -> null [5:15]
    |       |   `--SEMI -> ; [5:19]
    |       `--RCURLY -> } [6:4]
    `--RCURLY -> } [7:0]