terraform fmt adds extra lines in comment blocks

[BrianHicks]

Terraform Version

$ terraform -v
Terraform v0.6.15

Affected Resource(s)

n/a

Terraform Configuration Files

# this is a long comment block spanning multiple lines. I would expect
# `terraform fmt` to keep the lines together, but it doesn't.

Debug Output

https://gist.github.com/BrianHicks/45196caa7824eb6758ea071ecf2974b0

Expected Behavior

The comment block should have been left intact, as in the sample above.

Actual Behavior

Actual output:

# this is a long comment block spanning multiple lines. I would expect


# `terraform fmt` to keep the lines together, but it doesn't.

All newlines included.

Steps to Reproduce

1. paste the above configuration into x.tf
2. run terraform fmt x.tf
3. observe the resulting file contents

Important Factoids

Installed via homebrew

References

Couldn't find any.

[dcarley]

There's an issue and PR in the upstream parser for this:

• Multiline comments get a blank line in-between. hcl#108
• Allow printer to print single list file hcl#113

[dangerp]

I ran into this issue as well, and I found a fairly simple workaround. For any multiline comments that are not attached to a resource (meaning there is an empty line between the comment and the resource), simply use the HCL syntax for a multiline comment instead of multiple single line comments. For example, instead of

# this is a long comment block spanning multiple lines. I would expect
# `terraform fmt` to keep the lines together, but it doesn't.

do this instead:

/*
this is a long comment block spanning multiple lines. I would expect
`terraform fmt` to keep the lines together, but it only does so if you use 
proper multiline comment syntax
*/

As far as I can tell, the hcl printer is treating each standalone comment line as a separate comment, therefore they are separated by empty lines. I would still consider this a bug in hcl, but at least I can use terraform fmt without spurious empty lines being added.

[mitchellh]

This is fixed!

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.