Remove async function Has Fix

• Playground Link

Description

The async keyword in Python is used to define asynchronous functions that can be awaited.

In this example, we want to remove the async keyword from a function definition and replace it with a synchronous version of the function. We also need to remove the await keyword from the function body.

By default, ast-grep will not apply overlapping replacements. This means await keywords will not be modified because they are inside the async function body.

However, we can use the rewriter to apply changes inside the matched function body.

YAML

id: remove-async-def
language: python
rule:
  # match async function definition
  pattern:
    context: 'async def $FUNC($$$ARGS): $$$BODY'
    selector: function_definition
rewriters:
# define a rewriter to remove the await keyword
  remove-await-call:
    pattern: 'await $$$CALL'
    fix: $$$CALL # remove await keyword
# apply the rewriter to the function body
transform:
  REMOVED_BODY:
    rewrite:
      rewriters: [remove-await-call]
      source: $$$BODY
fix: |-
  def $FUNC($$$ARGS):
    $REMOVED_BODY

Example

async def main3():
  await somecall(1, 5)

Diff

async def main3(): 
  await somecall(1, 5) 
def main3(): 
  somecall(1, 5) 

Contributed by

Inspired by the ast-grep issue #1185