feat: Support .tofu files

[hinricht]

Put an x into the box if that apply:

• This PR introduces breaking change.
• This PR fixes a bug.
• This PR adds new functionality.
• This PR enhances existing functionality.

Description of your changes

Fixes #6

How can we test changes

Current behaviour:

$ git clonehttps://github.com/NorddeutscherRundfunk/opentofu-example.git
$ cd opentofu-example
$ echo "#" >> hello.tofu 
$ git add hello.tofu
$ git commit -m'test'
OpenTofu fmt.........................................(no files to check)Skipped
OpenTofu validate....................................(no files to check)Skipped
OpenTofu validate with tflint........................(no files to check)Skipped
[main c5fa2ee] test
 1 file changed, 1 insertion(+)

Behaviour of this PR:

$ git checkout support-tofu-files 
$ echo "#" >> hello.tofu 
$ git add hello.tofu
$ git commit -m'test'
OpenTofu fmt.............................................................Passed
OpenTofu validate........................................................Passed
OpenTofu validate with tflint............................................Failed
- hook id: tofu_tflint
- exit code: 2

Command 'tflint --init' successfully done:




TFLint in ./:
5 issue(s) found:

Warning: Missing version constraint for provider "null" in `required_providers` (terraform_required_providers)

  on hello.tf line 1:
   1: resource "null_resource" "hello_tf" {

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.9.1/docs/rules/terraform_required_providers.md

Warning: terraform "required_version" attribute is required (terraform_required_version)

  on hello.tf line 1:

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.9.1/docs/rules/terraform_required_version.md

Warning: Module should include a main.tf file as the primary entrypoint (terraform_standard_module_structure)

  on main.tf line 1:
   (source code not available)

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.9.1/docs/rules/terraform_standard_module_structure.md

Warning: Module should include an empty outputs.tf file (terraform_standard_module_structure)

  on outputs.tf line 1:
   (source code not available)

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.9.1/docs/rules/terraform_standard_module_structure.md

Warning: Module should include an empty variables.tf file (terraform_standard_module_structure)

  on variables.tf line 1:
   (source code not available)

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.9.1/docs/rules/terraform_standard_module_structure.md

[kvendingoldo]

Amazing, thank you!

[kvendingoldo]

Can you fix DCO, please?

[hinricht]

@kvendingoldo I fixed the DCO job, but I'm struggleing with the remaining jobs, i.e. https://github.com/tofuutils/pre-commit-opentofu/actions/runs/11363665717/job/31608100666?pr=14

Error: The subject "support .tofu files" found in the pull request title "feat: support .tofu files"
didn't match the configured pattern. Please ensure that the subject
starts with an uppercase character.

I already tried Feat: in the beginning of the PR title, but it didn't work neither. Can you help me here pls ?

[hinricht]

@kvendingoldo Nevermind, I fixed all CI jobs already.

[hinricht]

I updated the description with steps how to test this PR.

[kvendingoldo]

Great job!

[kvendingoldo]

This PR is included in version 2.1.0 🎉