Extra newline is inserted after beautifying code with anonymous function

[alundiak]

Description

Beautifying introduce extra new line in code. But I'm not sure it's bug.

Input

The code looked like this before beautification:

this.model.myMethod().then(function() {
	// code
}).catch(
	function() {
		// code
	}
);

1 empty line after catch( and before function() {

Expected Output

Now I am not sure what is expected.

Actual Output

The code actually looked like this after beautification:

this.model.myMethod().then(function() {
	// code
}).catch(

	function() {
		// code
	}
);

FYI

Such code is not changed by Beautifying:

this.model.myMethod().then(function() {
    // code
}).catch(function() {
    // code
});

Steps to Reproduce

• Install usage of grunt-jqbeautifier v 0.2.7 (it has dependency written in form "js-beautify": ">=1.4.2",)
• Verifiy that jsbeautifer installed 1.6.6

Environment

OS: Windows.
NodeJS 4.4.0, npm 2.4.12, grunt v 0.4.5

Settings

Example:
default by jsbeautify jsbeautifyrc

{
    "indent_size": 4,
    "indent_char": " ",
    "indent_level": 0,
    "indent_with_tabs": false,
    "preserve_newlines": true,
    "max_preserve_newlines": 10,
    "jslint_happy": false,
    "space_after_anon_function": false,
    "brace_style": "collapse,preserve-inline",
    "keep_array_indentation": false,
    "keep_function_indentation": false,
    "space_before_conditional": true,
    "break_chained_methods": false,
    "eval_code": false,
    "unescape_strings": false,
    "wrap_line_length": 0
}

My codebase grunt task:

jsbeautifier: {
	files: [srcDir + '/**/*.js', '!' + bowerDir + '/**', testDir + '/**/*.js'],
	options: {
		js: {
			indentWithTabs: true
		}
	}
},

Not sure, but maybe it's somehow related to the same cause as in #1060 or described.

[wcarmon]

+1 (we are experiencing the same with 1.6.6. Works fine in 1.6.4)

[bitwiseman]

@alundiak -
Thank you for the high-quality bug report.

function declarations that are not on the same line as the parenthesis are suppose to have a blank line before them.

For example, In a statement block:

a();

function a() {
    // Do stuff
}

function b() {
    // Do stuff
}

function c() {
    // Do stuff
}

I can see how, as a parameter of a method call, this might not be ideal.

@wcarmon - I see the same behavior between 1.6.6 and 1.6.4 for the given input. Please clarify.

[gagern]

Another use case where I'd rather avoid empty lines is when writing fallback functions like this:

var transformer =
    options.transformer ||
    globalSettings.transformer ||
    function(x) {
        return x;
    };

I'd say a function should have a preceding empty line if it is either declared in a statement, or used in an expression which is of the simple form ‹LHS› = function(…) {…}. Everything else should have newlines as given in the original code. This should cover uses of a function as an argument, or inside expressions like my || chain.

By the way, I too see this issue here and #1090 in our actual code base with 1.6.7 while 1.6.2 has no such issues. I've not yet worked out what aspect of the surrounding code makes this a new problem.

[gagern]

I did a quick git bisect. Both the original example and my test case got broken by 5fb9542 for 1.6.5.

[alundiak]

@bitwiseman Can we assume/treat mentioned SHA by @gagern as a bug in jsbeautify and it will be fixed in nearest release? Or this described behavior by me is closer to standard behavior of new jsBeautifier?

PS: How I spotted on this. I had setup of node modules, including grunt-jsbeautifier, and based on version setting of jsbeautify as dependency I receive new release when I did my project clean setup. Image my surprise, when a few files were beautified in a bit different way. So now I decide what the standard is/should be.

[bitwiseman]

@gagern - Again, good example and well said.
@alundiak - between your and gagern's examples, this case is definitely a bug, but I want to make sure we don't break related cases while fixing this.

Just to clarify, you'd like this to be unchanged:

this.model.myMethod().then(function() {
	// code
}).catch(
	function() {
		// code
	},
	function() {
		// code
	}
);