Error in ts.findAncestor caused by ASI

[tzengshinfu]

🔎 Search Terms

semicolon findAncestor
asi findAncestor

🕗 Version & Regression Information

5.8.3

⏯ Playground Link

No response

💻 Code

// Reference to the VSCode extension
import * as ts from 'typescript'

// The target JS code to analyze
const a = 1
const b = 2
const c = 3
(a + b) - c
//        ▲
//        │
//      node: ts.Node

// Get the parent binary expression
ts.findAncestor(node, ts.isBinaryExpression).getFullText()

🙁 Actual behavior

It shouldn't include 3.
│
▼
' 3
(a + b) - c'

🙂 Expected behavior

'
(a + b) - c'

Additional information about the issue

I'm planning to develop a VSCode extension, and one of its features involves parsing the AST of JavaScript code.
Most of the target JavaScript code uses ASI (Automatic Semicolon Insertion), which causes unexpected behavior when calling ts.findAncestor.

[MartinJohns]

The JavaScript

const c = 3
(a + b) - c

is equivalent to const c = 3(a + b) - c, so this looks alright to me.

[tzengshinfu]

Hi, MartinJohns,
It was my misunderstanding.
Due to certain reasons, the code was entered as (a + b) - c first,
and then const d = was entered afterward.
If it were a complete line like const d = (a + b) - c,
ASI would have worked correctly.
Thanks for your reply.

The JavaScript

const c = 3
(a + b) - c

is equivalent to const c = 3(a + b) - c, so this looks alright to me.