Terraform + Tofu Plugins Bug: terraform fmt + tofu fmt erroneously run against **.tf.json files

[Gowiem]

Info

When committing / changing our backend.tf.json file (which is a standard file in both tofu + terraform), both plugins are trying to run their fmt command against those files. This results in the following error:

trunk_cli_version: 1.22.8
title: terraform exited with exit_code=2
report:
  - terraform exited with exit_code=2
  - linter:
      command: |
        /<MY_USER_PATH>/.cache/trunk/tools/terraform/1.1.0-6bc9ed0aa441bfb0bf13ee36e04a2bde/terraform fmt -no-color -
      stdin_path: |
        /private/var/folders/7l/fp_bz3gx6yzg24hw08ww9vp00000gn/T/trunk-501/GlML4Y/root-modules/kms/backend.tf.json
      run_from: /private/var/folders/7l/fp_bz3gx6yzg24hw08ww9vp00000gn/T/trunk-501/GlML4Y
      timeout: 10m
      rerun: (cd /private/var/folders/7l/fp_bz3gx6yzg24hw08ww9vp00000gn/T/trunk-501/GlML4Y; cat /private/var/folders/7l/fp_bz3gx6yzg24hw08ww9vp00000gn/T/trunk-501/GlML4Y/root-modules/kms/backend.tf.json | env -i PATH=/<MY_USER_PATH>/.cache/trunk/tools/terraform/1.1.0-6bc9ed0aa441bfb0bf13ee36e04a2bde:/<MY_USER_PATH>/.cache/trunk/tools/terraform/1.1.0-6bc9ed0aa441bfb0bf13ee36e04a2bde HOME=/<MY_USER_PATH> /<MY_USER_PATH>/.cache/trunk/tools/terraform/1.1.0-6bc9ed0aa441bfb0bf13ee36e04a2bde/terraform fmt -no-color -)
      affects_cache:
        []
      direct_configs:
        []
      exit_status: exited
      exit_code: 2
      stdout: (none)
      stderr: |

        Error: Argument or block definition required

          on <stdin> line 1:
           1: {

        An argument or block definition is required here.


    parser: |
      (none)

If you run terraform fmt against that file directly via terraform fmt -no-color backend.tf.json then you get the following:

Error: Only .tf, .tfvars, and .tftest.hcl files can be processed with terraform fmt

This goes to say that trunk should not be trying to run fmt against these ****.tf.json files and this now causing a false error.

We've been using these plugins for a while and this is the first that we're running into this. So we believe something must have changed upstream in trunk check itself?

trunk.yaml

version: 0.1
cli:
  version: 1.22.8
plugins:
  sources:
    - id: trunk
      ref: v1.6.6
      uri: https://github.com/trunk-io/plugins
lint:
  disabled:
    # TODO: Re-enable checkov once the below issue is fixed:
    # https://github.com/bridgecrewio/checkov/issues/6915
    # This is fixed in https://github.com/bridgecrewio/checkov/pull/6918, but that is not released yet.
    - checkov
  enabled:
    - [email protected]
    - [email protected]
    - [email protected]
    - [email protected]
    - [email protected]
    - [email protected]
    - [email protected]
    - git-diff-check
    - [email protected]
    - [email protected]
    - [email protected]
    - [email protected]
runtimes:
  enabled:
    - [email protected]
    - [email protected]
    - [email protected]
actions:
  disabled:
    - trunk-announce
  enabled:
    - trunk-cache-prune
    - trunk-check-pre-push
    - trunk-fmt-pre-commit
    - trunk-upgrade-available

[TylerJang27]

Hi! Thanks for flagging this. I have a repro and confirm the issue. This file config has been the case in Trunk for as long as I can remember, and we haven't made any recent changes that would have affected this, so I'm not sure why this would suddenly crop up for you.

Regardless, I will raise a fix to handle this. In the meantime, you can always add an ignore for those .tf.json files.