The following bit of code is formatted in 2 passes:

$this->addFlash('success', sprintf(
    'A bit of text.'
));

$this->addFlash('success', sprintf(
    'A bit of text.'
)
);

$this->addFlash(
    'success',
    sprintf(
        'A bit of text.'
    )
);

Formatting options used:

"php.format.rules.arrayInitializersNewLineBeforeFirstElement": true,
"php.format.rules.newLineAfterImplements": true,
"php.format.rules.forStatementNewLineBeforeRightParen": true,
"php.format.rules.groupUseNewLineBeforeFirstDeclaration": true,
"php.format.rules.ifStatementNewLineAfterLeftParen": true,
"php.format.rules.ifStatementNewLineBeforeRightParen": true,
"php.format.rules.forStatementNewLineAfterLeftParen": true,
"php.format.rules.declParametersNewLineBeforeRightParen": true,
"php.format.rules.declParametersNewLineAfterLeftParen": true,
"php.format.rules.declCompactEmptyBody": true,
"php.format.rules.chainedMethodCallsSemicolonOnNewLine": true,
"php.format.rules.callParametersNewLineBeforeRightParen": true,
"php.format.rules.whileStatementNewLineAfterLeftParen": true,
"php.format.rules.whileStatementNewLineBeforeRightParen": true,
"php.format.rules.callParametersNewLineAfterLeftParen": true,
"php.format.rules.arrayInitializersNewLineAfterLastElement": true,
"php.format.rules.arrayInitializersAlignKeyValuePairs": false,
"php.format.rules.spaceBeforeParenthesesInControlStatements": true,
"php.format.rules.spaceBeforeParenthesesInArrowFunctions": true,
"php.format.rules.spaceAroundConcatenation": true,
"php.format.rules.spaceAfterUnaryNot": false,
"php.format.rules.spaceAfterCast": true,
"php.format.rules.openBraceOnNewLineForTypes": true,
"php.format.rules.openBraceOnNewLineForNamespaces": true,
"php.format.rules.openBraceOnNewLineForFunctions": true,
"php.format.rules.endWithNewLine": true,
"php.format.rules.removeReduntandClosingTag": true,
"php.format.rules.indentBraces": false,
"php.format.rules.nullConstantCasing": "lowercase",
"php.format.rules.booleanConstantCasing": "lowercase",
"php.format.rules.addCommaAfterLastDeclParameter": false,
"php.format.rules.addCommaAfterLastCallParameter": false,
"php.format.rules.addCommaAfterLastArrayElement": true,