trailing commas on dictionaries should be all or none

[docwhat]

Introduction

Uneven commas can make terraform code confusing. On dictionaries, they should either be on all or none.

I would expect that tflint would raise an warning on this snippet of code:

locals {
  a_dictionary = {
    "one"  = "fish"
    "two"  = "fish",
    "red"  = "fish"
    "blue" = "fish"
  }
}

I would expect the two line to be flagged as the rest of the lines do not have commas.

Proposal

The rule should take these values:

• all: All dictionary entries should end in a comma.
• none: All dictionary entries should not end in a comma.
• match: All the dictionary entries in a given dictionary should be the same; either all commas or all without commas.

References

None