fix: avoid adding parens to static property in new expression

[sorafujitani]

Summary

Fixes #2441

When formatting code like new Yii::$app->class([]), the formatter was incorrectly adding parentheses to produce new Yii::$app()->class([]). This changes the semantics from accessing a static property (Yii::$app) to calling a static method (Yii::$app()).

Changes

• Added logic in printer.mjs to skip adding parentheses for new expressions when:
  • The new is inside a member chain (parent is a lookup node or call)
  • The constructor has no arguments
  • The original source did not have parentheses
  • The target is a staticlookup (e.g., Yii::$app)

Test plan

• Added test cases in tests/parens/new.php for Issue Bug: Prettier incorrectly adds parentheses when using new with a static property #2441
• All existing tests pass (592 tests)
• AST comparison tests pass (1166 tests)

[czosel]

I took a closer look, because the need for options.originalText.charAt( is a bit of a code smell - the AST should contain all the information to tell the two cases apart, but currently it doesn't. Both

new Foo::$bar->baz();

and

new Foo::$bar()->baz();

are parsed like this:

{
  "kind": "expressionstatement",
  "expression": {
    "kind": "call",
    "what": {
      "kind": "propertylookup",
      "what": {
        "kind": "new",
        "what": {
          "kind": "staticlookup",
          "what": {
            "kind": "name",
            "name": "Foo",
            "resolution": "uqn"
          },
          "offset": {
            "kind": "variable",
            "name": "bar",
            "curly": false
          }
        },
        "arguments": []
      },
      "offset": {
        "kind": "identifier",
        "name": "baz"
      }
    },
    "arguments": []
  }
}

While nikic/PHP-Parser parses

new Foo::$bar->baz();

like this:

array(
    0: Stmt_Expression(
        expr: Expr_New(
            class: Expr_PropertyFetch(
                var: Expr_StaticPropertyFetch(
                    class: Name(
                        name: Foo
                    )
                    name: VarLikeIdentifier(
                        name: bar
                    )
                )
                name: Identifier(
                    name: baz
                )
            )
            args: array(
            )
        )
    )
)

and

new Foo::$bar()->baz();

like this:

array(
    0: Stmt_Expression(
        expr: Expr_MethodCall(
            var: Expr_New(
                class: Expr_StaticPropertyFetch(
                    class: Name(
                        name: Foo
                    )
                    name: VarLikeIdentifier(
                        name: bar
                    )
                )
                args: array(
                )
            )
            name: Identifier(
                name: baz
            )
            args: array(
            )
        )
    )
)

So I think this needs to be fixed in the parser, which might even include a bit of a refactor since the general AST structure differes quite a bit between the two parsers (?).

[MasonD]

Indeed, the parser itself is incorrect in its handling of the new operator. It might be more illustrative to use parentheses like this:

new (Foo::$bar->baz)();

The above is identical semantically to new Foo::$bar->baz();, but results in the following AST, (new Foo::$bar->baz(); should give this same AST but is bugged)

{
  "kind": "expressionstatement",
  "expression": {
    "kind": "new",
    "what": {
      "kind": "propertylookup",
      "what": {
        "kind": "staticlookup",
        "what": {
          "kind": "name",
          "name": "Foo",
          "resolution": "uqn"
        },
        "offset": {
          "kind": "variable",
          "name": "bar",
          "curly": false
        }
      },
      "offset": {
        "kind": "identifier",
        "name": "baz"
      }
    },
    "arguments": []
  }
}

[czosel]

Thanks for clarifying @MasonD! I created an issue over at glayzzle/php-parser#1177.