Investigate called CallExpressions situation

[Andarist]

Decide how to annotate this one:

fn()()()

At the moment it produces:

/*#__PURE__*//*#__PURE__*//*#__PURE__*/fn()()()

Which needs to be changed somehow.

[Andarist]

mishoo/UglifyJS#2331
At the moment pure callable expressions are considered as completely pure - this means that:

• it is sufficient to annotate only the outermost callable expression
• if callable expression is used as callee in pure callable expression its contents are considered pure, even if containing other, possibly impure, call expressions

The latter is quite a mouthful, so let's illustrate it with an example:

input code

// ./file.js
var b = /*#__PURE__*/fn(arg1())(arg2())(arg3())

output code

$ uglifyjs --toplevel -mc passes=3 ./file.js
arg3();