Allow to use meta variable captured outside of rewrite rule inside the rewriter

[ptorbynskyy]

⭐ Suggestion

I would like to be able to use meta variable that captured outside of rewrite rule inside it.

💻 Use Cases

Here is my case
I tried to replace spread with set of calls.

Source:

createService(
    ...c.resolve("A", "B", "С")
)

Goal:

createService(
    c.resolve("A"),
    c.resolve("B"),
    c.resolve("C")
)

Rule:

# YAML Rule is more powerful!
# https://ast-grep.github.io/guide/rule-config.html#rule
rule:
   kind: spread_element
   has: 
      kind: call_expression
      pattern: $NAME.resolve($$$IDENTS)
rewriters:
  - id: rewrite-identifer
    rule:
      pattern: $IDENT
      kind: string
    fix: $NAME.resolve($IDENT)
transform:
  RESOLVES:
    rewrite:
      rewriters: [rewrite-identifer]
      source: $$$IDENTS
      joinBy: "\n"
fix: $RESOLVES

$NAME is empty inside the rewriters.
I suggest to make external context available.

Additional Links:

• my case
• Discord discussion

[HerringtonDarkholme]

thanks for reporting. I will try to implement it in 0.21.x releases

[HerringtonDarkholme]

• Pass variables from outside to rewriters
• Pass captured AST nodes to rewriters fix