Importing json/yaml crashes nls

[simonzkl]

Describe the bug

Importing json/yaml crashes nls. It works fine in nickel.

To Reproduce

let a = import "test.json" in
a

[2023-06-19T08:37:03Z DEBUG nls::linearization] adding term: Import("test.json") @ Original(RawSpan { src_id: FileId(5), start: ByteIndex(8), end: ByteIndex(26) })
[2023-06-19T08:37:03Z DEBUG nls::linearization] Add wildcard item: Import("test.json")
[2023-06-19T08:37:03Z DEBUG nls::linearization] adding term: Var(Ident { label: "a" }) @ Original(RawSpan { src_id: FileId(5), start: ByteIndex(30), end: ByteIndex(31) })
[2023-06-19T08:37:03Z DEBUG nls::linearization] adding usage of variable a followed by chain None
[2023-06-19T08:37:03Z DEBUG nls::linearization] linearizing
[2023-06-19T08:37:03Z DEBUG nls::linearization] unresolved references: []
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', lsp/nls/src/cache.rs:104:97
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', /private/tmp/nix-build-nls-1.0.0.drv-0/nls-1.0.0-vendor.tar.gz/lsp-server/src/stdio.rs:29:37

Expected behavior
Should not crash.

Environment

• OS name + version: MacOS 13.4
• Version of the code: nickel-lang-lsp 1.0.0

[simonzkl]

Anecdotally, I've also had it panic in a different location for the same reason:

nickel/lsp/nls/src/linearization/mod.rs

Lines 463 to 466 in 00b6ce9

	// This is safe because the import file is resolved, before we linearize
	// the containing file, therefore the cache MUST have the term stored.
	let term = lin.cache.get(*file).unwrap();
	let position = final_term_pos(&term);

[yannham]

@simonzkl I have a fix for my simple test case (and which makes sense with respect to the original location of the panic). But I didn't hit the second location yet. Maybe it's an artifact of the first issue, but just in case, would you mind sharing the JSON file you tried?

[simonzkl]

After narrowing it down, I think just switching to yaml triggers this one. It's a different line than I wrote though. Mentioned it from memory, so it was incorrect.

import "test.yaml"

[2023-06-20T06:58:23Z TRACE nls::files] Parsed, checking types
[2023-06-20T06:58:23Z DEBUG nls::linearization] adding term: Null @ None
[2023-06-20T06:58:23Z DEBUG nls::linearization] linearizing
[2023-06-20T06:58:23Z DEBUG nls::linearization] unresolved references: []
[2023-06-20T06:58:23Z DEBUG nls::linearization] adding term: ResolvedImport(FileId(4)) @ Original(RawSpan { src_id: FileId(3), start: ByteIndex(1), end: ByteIndex(19) })
thread 'main' panicked at 'TermPos::unwrap', lsp/nls/src/linearization/mod.rs:471:38
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[Error - 08:58:23] Connection to server got closed. Server will not be restarted.

[yannham]

Ok, this is more in line with my own findings. Thanks!