Fix #365

[lucivpav]

Fixes issue #365 (maybe more).

Changes:

• fix of processing of parenthesized expressions that start with comments
• add tests
• the trailing comments are still the same (incorrect placement), but they do not affect the syntax (can be addressed in a future PR)
• blank line preservation: seems no new problems with this

[lucivpav]

@micschro

[lucivpav]

arrow functions are affected too! #426 (comment)
Solved.

[lucivpav]

Maybe these kind of bugs should be treated from another point of view - if a parenthesis expression contains comments, then the parenthesis must stay.

[Meir017]

@lucivpav the new test is failing...

[lucivpav]

It is failing on purpose, because I did not implement a fix of arrow functions in this PR yet :)

[Meir017]

another scenario that's related to broken parens

(1).toString()

is generated as

1.toString()

which is invalid js :(

[papandreou]

1.toString()

Not sure if you're saying that's broken on this branch or in the latest release, but it's not reproducible on master:

> require('escodegen').generate({ type: 'CallExpression', callee: { type: 'MemberExpression', object: { type: 'Literal', value: 1 }, property: { type: 'Identifier', name: 'toString' }, computed: false, optional: false }, arguments: [], optional: false })
'1 .toString()'

[Meir017]

1.toString()

Not sure if you're saying that's broken on this branch or in the latest release, but it's not reproducible on master:

require('escodegen').generate({ type: 'CallExpression', callee: { type: 'MemberExpression', object: { type: 'Literal', value: 1 }, property: { type: 'Identifier', name: 'toString' }, computed: false, optional: false }, arguments: [], optional: false })
'1 .toString()'

the output should wrap the Literal number with parens, running the generated code fails with a syntax error

[papandreou]

Did you notice the space between . and toString? That makes it run.

[Meir017]

@papandreou my bad.
although I still think this is incorrect behavior is incorrect but it's not very important

[papandreou]

You're of course entitled to your opinion, but why do you think it's incorrect? ;)

[Meir017]

the behavior isn't consistent.
for example:

(1).toString(); // outputs "1"
(1+2).toString(); // outputs "3"
1 + 2 .toString(); // outputs "12"

is converted to

1 .toString(); // outputs "1"
(1 + 2).toString(); // outputs "3"
1 + 2 .toString(); // outputs "12"

maybe this is just a js thing that is confusing...

[papandreou]

maybe this is just a js thing that is confusing...

Yeah, I think those examples are JavaScript being weird more than escodegen :)

[lucivpav]

@michaelficarra could you please take a look at this PR, when you have time?

[lucivpav]

Do not merge as it is now. I discovered a bug in cases like these:

class MyClass {
    /**
     * description
     */
    foo(a, b) {
        a.bar(b);
    }
}