feat(terraform-docs): Add support for replace mode for TF 0.12+; Use native saving to file for TF 0.12+. Both requires terraform-docs v0.12.0+ which released in 2021.

[MaxymVlasov]

Important

Should be merged after #706

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

Closes #179

How can we test changes

.terraform-docs.yml:

formatter: "md"
output:
  mode: replace
  template: |-
        {{ .Content }}

.pre-commit-config.yaml:

repos:
  - repo: https://github.com/antonbabenko/pre-commit-terraform
    rev: ece0c17b91c17b29201aba379f99e79f59813438
    hooks:
      - id: terraform_docs
        args:
          - --args=--config=.terraform-docs.yml
          ## Also CLI options have precedence over YAML config
          ##  that's default behavior of major chunk of tools, so we just preserve it.
          #- --args=--output-mode=inject

[yermulnik]

JFYI: I'm still concerned with picking last key instead of first despite YAML requires keys to be unique — https://yaml.org/spec/1.2-old/spec.html#id2764044

The content of a mapping node is an unordered set of key: value node pairs, with the restriction that each of the keys is unique.

[MaxymVlasov]

In YAML you can do next

foo: &anchor
    key: 111

bar: 
    <<: *anchor
    key: 222

I not sure what words in https://yaml.org/spec/1.2-old/spec.html#id2765878 exactly means, but it actually same to

foo:
    key: 111

bar: 
    key: 111
    key: 222

[yermulnik]

I might have worded it a bit ambiguous. What I mean is when you do grep -A1000 -e '^output:$' "$config_file" | grep -E '^[[:space:]]+mode:' | tail -n 1, you actually allow the below YAML within 1001 lines starting from the first match of ^output:$:

output:
    mode: 111

output: 
    mode: 222
    mode: 333

The output is what YAML expects to be unique node. Else YAML is incorrect.
From my point of view the first occurrence of output.mode key with value of 111 is what must be rendered as value for output.mode, whilst your implementation means the output.mode key with value 333 is what is taken as correct value.

[yermulnik]

Given we're trying to employ as less third-party tools as feasible and to keep solution simple, I'd suggest we take first occurrence of output.mode since duplicates are not allowed.

[antonbabenko]

This PR is included in version 1.94.0 🎉