Files starting with a multiline comment lead to out of range errors in LSP

[dbanck]

We discovered in #1050 (unrelated to the bug reported in #1050) that having a file start with a multiline comment results in out of range errors for all kinds of LSP requests.

Server Version

0.29.1

Terraform Configuration Files

/********************************
 Some comment
********************************/

data "google_project" "project" {
  project_id = var.project_id
}

Log Output

2022/08/26 15:34:17 rpc_logger.go:29: Incoming request for "textDocument/documentLink" (ID 2): {"textDocument":{"uri":"file:///Users/dbanck/tmp/issue1050/main.tf"}}
2022/08/26 15:34:17 rpc_logger.go:29: Incoming request for "textDocument/documentSymbol" (ID 1): {"textDocument":{"uri":"file:///Users/dbanck/tmp/issue1050/main.tf"}}
2022/08/26 15:34:17 provider_schema.go:256: PSS: getting provider schema (/Users/dbanck/tmp/issue1050, registry.terraform.io/-/google, )
2022/08/26 15:34:17 provider_schema.go:256: PSS: getting provider schema (/Users/dbanck/tmp/issue1050, registry.terraform.io/-/google, )
2022/08/26 15:34:17 opts.go:218: Received response for callback "2"
2022/08/26 15:34:17 opts.go:218: Posting server call "client.refreshModuleCalls" 
2022/08/26 15:34:17 opts.go:218: Received response for callback "3"
2022/08/26 15:34:17 opts.go:218: Posting server call "workspace/semanticTokens/refresh" 
2022/08/26 15:34:17 opts.go:218: Received response for callback "4"
2022/08/26 15:34:17 rpc_logger.go:50: Response to "textDocument/documentSymbol" (ID 1): [{"name":"data \"google_project\" \"project\"","kind":5,"range":{"start":{"line":4,"character":0},"end":{"line":6,"character":1}},"selectionRange":{"start":{"line":4,"character":0},"end":{"line":6,"character":1}},"children":[{"name":"project_id","kind":14,"range":{"start":{"line":5,"character":2},"end":{"line":5,"character":29}},"selectionRange":{"start":{"line":5,"character":2},"end":{"line":5,"character":29}}}]}]
2022/08/26 15:34:17 opts.go:218: Completed 1 requests [50.012484ms elapsed]
2022/08/26 15:34:17 rpc_logger.go:45: Error for "textDocument/documentLink" (ID 2): [-32098] main.tf: position 1,1 is out of range main.tf:3,34-8,1
2022/08/26 15:34:17 opts.go:218: Completed 1 requests [3.859428ms elapsed]
[Error - 3:34:17 PM] Request textDocument/documentLink failed.
  Message: main.tf: position 1,1 is out of range main.tf:3,34-8,1
  Code: -32098 
2022/08/26 15:34:17 opts.go:218: Received request batch of size 1 (qlen=0)
2022/08/26 15:34:17 opts.go:218: Dequeued request batch of length 1 (qlen=0)
2022/08/26 15:34:17 rpc_logger.go:29: Incoming request for "textDocument/semanticTokens/full" (ID 3): {"textDocument":{"uri":"file:///Users/dbanck/tmp/issue1050/main.tf"}}
2022/08/26 15:34:17 provider_schema.go:256: PSS: getting provider schema (/Users/dbanck/tmp/issue1050, registry.terraform.io/-/google, )
2022/08/26 15:34:17 rpc_logger.go:45: Error for "textDocument/semanticTokens/full" (ID 3): [-32098] main.tf: position 1,1 is out of range main.tf:3,34-8,1
2022/08/26 15:34:17 opts.go:218: Completed 1 requests [3.050845ms elapsed]
[Error - 3:34:17 PM] Request textDocument/semanticTokens/full failed.
  Message: main.tf: position 1,1 is out of range main.tf:3,34-8,1
  Code: -32098

Expected Behavior

No errors, usual responses to all requests.

Actual Behavior

Out of range errors for requests with a position lower than line 3.

Degraded DX, because of broken features like semantic tokens.

Proposal

Raise this issue upstream in HCL

[dbanck]

Filed this as an upstream bug in HCL: hashicorp/hcl#551

[radeksimko]

This is somewhat related to #105 - if we implement region folding, comment blocks are likely one of those things which users will want to fold, so having them parsed correctly by HCL (currently they're ignored) would be necessary there too.

I believe HCL parser(s) currently ignore comments, which the described bug may be side effect of.

[radeksimko]

@dbanck came up with an idea for a local fix (without having to touch upstream), which involves changing the logic for textDocument/documentLink and relevant semantic tokens method to avoid lookup with position as that's not necessary:

https://github.com/hashicorp/hcl-lang/blob/c6076d3b6a2868550b601d4ac7c23f8c395f7dc1/decoder/links.go#L21-L24