JS autocomplete doesn't work for object literal shorthands

[jurajmatus]

TS Template added by @mjbvz

TypeScript Version: 4.1.0-dev.20201026

Search Terms

• suggest / suggestion
• intellisense
• object short hand

---

• VSCode Version: 1.51.0-insider (7a3bdf4)
• OS Version: Arch Linux

Steps to Reproduce:

1. Suppose there are variables in the current context (be it local or global)
2. Create an object literal and try to use a variable in a shorthand style
3. No semantic autocompletion is offered, and textual autocomplete is only offered after 3 characters

GIF file to better demonstrate:

Does this issue occur when all extensions are disabled?: Yes

[orange4glace]

If you don't mind, I'd like to work with this issue. FYI @andrewbranch

[andrewbranch]

Sounds good @orange4glace, let me know if you get stuck. You have about a month and a half before we need to get a fix in.

[orange4glace]

@andrewbranch Thanks for the reply! I have one question for this.
I'm planning to change the code like this.
Every tests are passed except completionListAtIdentifierDefinitionLocations_destructuring, which is,

/// <reference path='fourslash.ts' />

//// var [x/*variable1*/

//// var [x, y/*variable2*/

//// var [./*variable3*/

//// var [x, ...z/*variable4*/

//// var {x/*variable5*/

//// var {x, y/*variable6*/

//// function func1({ a/*parameter1*/

//// function func2({ a, b/*parameter2*/
                         ~
                         Getting Global Autocompletion

verify.completions({ marker: test.markers(), exact: undefined });

As l understood, the parenthesis { of the last line following by the func2( is recognized as ObjectLiteral with any type rather than ObjectBinding since the line is getting following error,

var [x/*variable1*/

var [x, y/*variable2*/

var [./*variable3*/

var [x, ...z/*variable4*/

var {x/*variable5*/

var {x, y/*variable6*/

function func1({ a/*parameter1*/

function func2({ a, b/*parameter2*/



'}' expected.ts(1005)
41259.ts(15, 16): The parser expected to find a '}' to match the '{' token here.
41259.ts(13, 16): The parser expected to find a '}' to match the '{' token here.

I'm curious that,

1. Is the test case valid one even though there's an syntax error? (Original PR for testcase : Less aggresive completion list #1767)
2. If so, Fixing the code to satisfy both original issue and the testcase seems pretty hard as I think.

I'm very new to this community and anything that can be helped would be much appreciated!

[andrewbranch]

We definitely want test cases that have syntax errors because they reflect half-written code as though a user is actively editing, and we want completions to work in those cases. That said, any particular assertion in a test like this might become wrong and need to be updated. What completion is showing up there?

[orange4glace]

With my modified version, it autocompletes global symbols at,

....
var {x, y/*variable6*/
function func1({ a/*parameter1*/
function func2({ a, b/*parameter2*/
                    ~
                    Global symbols Autocompletion

whereas with Typescript v4.0.5, it autocompletes nothing. (Playground)

Currently, the compiler parses the testcase code like this,

/* Statement #0 Starts (VariableStatement) */
var [x
/* Statement #1 Starts (VariableStatement) */
var [x, y
/* Statement #2 Starts (VariableStatement) */
var [.
/* Statement #3 Starts (VariableStatement) */
var [x, ...z
/* Statement #4 Starts (VariableStatement) */
var {x
var {x, y
function func1/* Statement #5 Starts (ExpressionStatement) */({ a
function func2({ a, b

The opening bracket { in the func2({ a, b is recognized as an ObjectLiteralExpression even though it looks like (or it should be) an ObjectBindingPattern, finally it autocompletes with global symbols.

[andrewbranch]

I think that’s probably alright. Can you go ahead and open a draft PR so we can make a playground build?

[orange4glace]

Sure! I've just opened it. :)