Incorrectly merging built-in and user config languages.toml files for typescript lsp

[sno2]

Reproduction steps

You need to have deno installed to be able to reproduce and consult wiki for helix config/log directories.

1. Create an empty languages.toml in the Helix config directory.
2. Copy in the text from helix/languages.toml
3. Navigate to the language entry that has a name of typescript
4. Change the language-server value to be of { command = "deno", args = ["lsp"] } and save
5. Create a dummy file with a ts file extension
6. Insert the following code:

console.log("Hello, world!");

7. Close helix
8. Open the file in helix again with the -v flag
9. Open the helix log file and see the errors listed below.

Environment

• Platform: Windows
• Helix version: 0.5

C:\Users\carte\AppData\Local\helix\helix.log

2021-11-06T21:20:10.786 helix_lsp::transport [INFO] -> {"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{"textDocument":{"codeAction":{"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["","quickfix","refactor","refactor.extract","refactor.inline","refactor.rewrite","source","source.organizeImports"]}}},"completion":{"completionItem":{"snippetSupport":false},"completionItemKind":{}},"hover":{"contentFormat":["markdown"]}},"window":{"workDoneProgress":true}},"processId":20380,"rootUri":null},"id":0}
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "\u{1b}[0m\u{1b}[1m\u{1b}[31merror\u{1b}[0m: Found argument '--stdio' which wasn't expected, or isn't valid in this context\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "USAGE:\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "    deno [OPTIONS] [SUBCOMMAND]\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "For more information try --help\n"
2021-11-06T21:20:10.870 helix_lsp::transport [ERROR] err <- "\n"
2021-11-06T21:20:10.876 helix_lsp::transport [ERROR] err: <- StreamClosed
2021-11-06T21:20:10.876 helix_lsp::transport [ERROR] err: <- StreamClosed

[sno2]

You can confirm this bug by replacing the merge_toml_tests module in helix-core/lib.rs with the following code:

#[cfg(test)]
mod merge_toml_tests {
    use super::merge_toml_values;

    #[test]
    fn language_tomls() {
        use toml::Value;

        const USER: &str = r#"
        [[language]]
        name = "typescript"
        test = "bbb"
        indent = { tab-width = 4, unit = "    ", test = "aaa" }
        language-server = { command = "deno", args = ["lsp"] }
        "#;

        let base: Value = toml::from_slice(include_bytes!("../../languages.toml"))
            .expect("Couldn't parse built-in langauges config");
        let user: Value = toml::from_str(USER).unwrap();

        let merged = merge_toml_values(base, user);
        let languages = merged.get("language").unwrap().as_array().unwrap();
        let ts = languages
            .iter()
            .find(|v| v.get("name").unwrap().as_str().unwrap() == "typescript")
            .unwrap();
        let ts_indent = ts.get("indent").unwrap();

        // We changed tab-width and unit in indent so check them if they are the new values
        assert_eq!(ts_indent.get("tab-width").unwrap().as_integer().unwrap(), 4);
        assert_eq!(ts_indent.get("unit").unwrap().as_str().unwrap(), "    ");
        // We added a new keys, so check them
        assert_eq!(ts.get("test").unwrap().as_str().unwrap(), "bbb");
        assert_eq!(ts_indent.get("test").unwrap().as_str().unwrap(), "aaa");
        assert_eq!(
            ts.get("language-server")
                .unwrap()
                .get("args")
                .unwrap()
                .as_array()
                .unwrap(),
            &vec![Value::String("lsp".into())],
        );
    }
}

It will then give you this error in the tests:

failures:

---- merge_toml_tests::language_tomls stdout ----
thread 'merge_toml_tests::language_tomls' panicked at 'assertion failed: `(left == right)`
  left: `[String("--stdio"), String("lsp")]`,
 right: `[String("lsp")]`', helix-core\src\lib.rs:178:9


failures:
    merge_toml_tests::language_tomls

[archseer]

Need to reopen this sadly as I had to revert #1004. It fixed the bug, but it stopped merging the built in languages.toml with the user overrides, so all grammars had to be specified in the user config. We want to merge the toplevel languages array, but replace any nested arrays.

[the-mikedavis]

#2145 had to be reverted as well for other merging bugs.