use-fstring.yaml

# This file contains optional rules
# that spot when f-string should be used
# instead of an older string formatting mechanism.
#
# Related default rules:
#
# https://docs.sourcery.ai/Reference/Default-Rules/refactorings/use-fstring-for-concatenation/
# https://docs.sourcery.ai/Reference/Default-Rules/refactorings/use-fstring-for-formatting/

rules:
  # You can use this rule in the Sourcery CLI with the --enable option:
  #
  # sourcery review --enable no-str-format .
  #
  # To review with this rule and the related default f-string rules:
  #
  # sourcery review --enable use-fstring .
  #
- id: no-str-format
  description: Use f-string instead of `str.format`
  explanation: |
    f-string is less verbose and faster than `str.format()`

    f-string was introduced to use the same syntax and machinery as `str.format()`, but solve some of its issues:

    * Verbosity.
    * The placeholder and the replacement value are often far away from each other.

    See the [Rationale section of PEP-498](https://peps.python.org/pep-0498/#rationale).

  pattern: ${text}.format(...)
  condition: text.has_type("str")
  tests:
  - match: "'{0}. place'.format(placement)"
  - match: "'{0}. chapter {1}'.format(nr, title)"
  - match: |
      template = "{0}. place"
      template.format(placement)
  - no-match: |
      sth = CustomObject()
      sth.format(placement)

rule_tags:
  use-fstring:
  - no-str-format
  - use-fstring-for-concatenation
  - use-fstring-for-formatting