Description

This PR fixes handling of empty or undefined metavariables.

Suppose if we have (1) the following pattern:

pattern: |
  resource "hoge" :[NAME] {
    b = 2
    :[...C]
  }

and (2) the following code to match (in HCL, for example):

  resource "hoge" "foo" {
    b = 2
  }

and (3) the following rewrite option:

rewrite: |
  resource "hoge" :[NAME] {
    b = 3
    :[...C]
  }

The current version of Shisho emits the rewritten code with an unnecessary newline, due to metavariable C, as follows:

resource "hoge" "foo" {
  b = 3
  
}

This PR changes this behaviour. In detail, now Shisho emits the following clean output:

resource "hoge" "foo" {
  b = 3
}

Checklist

• I opened a draft PR or added the [WIP] to the title if my PR is not ready for review.
• I have reviewed the code by myself.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• I have added tests enough to show how your code behaves and that your code works as expected.

Additional Notes

N/A