ark: Autocomplete of environment variables not working for Sys.getenv()

[noamross]

tl;dr: In https://github.com/posit-dev/ark/blob/398cfb945edb6d0be4552929c30e346c794ec517/crates/ark/src/modules/positron/completions.R#L76-L83, changing "x" to "x = NULL" fixes autocompletion. Will PR if desired.

System details:

Positron and OS details:

Positron Version: 2024.09.0 (Universal) build 27
Code - OSS Version: 1.92.0
Commit: d996153
Date: 2024-09-11T02:38:46.408Z (2 days ago)
Electron: 30.1.2
Chromium: 124.0.6367.243
Node.js: 20.14.0
V8: 12.4.254.20-electron.0
OS: Darwin arm64 23.6.0

Interpreter details:

R 4.4.1

Describe/Steps to reproduce the issue:

In an R script, Quarto document R cell, or console, typing Sys.getenv( and pressing TAB does not present environment variables for autocompletion:

It does work for Sys.setenv:

Completions also work for library(), options(), and getOption().

It does not matter if I prefix Sys.getenv( with base:: or base:::.

I can retrieve the custom completion:

> .ps.completions.getCustomCallCompletions("Sys.getenv", "x", "name")
[[1]]
 [1] "_"                                  "__CF_USER_TEXT_ENCODING"           
 [3] "__CFBundleIdentifier"               "COLORTERM"                         
 [5] "COMMAND_MODE"                       "DISPLAY"                           
 [7] "EDITOR"                             "ELECTRON_RUN_AS_NODE"              
 [9] "GIT_ASKPASS"                        "HOME"                              
[11] "HOMEBREW_CELLAR"                    "HOMEBREW_PREFIX"                   
[13] "HOMEBREW_REPOSITORY"                "INFOPATH"                          
[15] "LANG"                               "LN_S"                              
[17] "LOGNAME"                            "MAKE"                              
[19] "MallocNanoZone"                     "OLDPWD"                            
[21] "ORIGINAL_XDG_CURRENT_DESKTOP"       "PAGER"                             
[23] "PATH"                               "POSITRON"                          
[25] "POSITRON_VERSION"                   "PWD"                               
[27] "R_BROWSER"                          "R_BZIPCMD"                         
[29] "R_GZIPCMD"                          "R_HOME"                            
[31] "R_LIBS_SITE"                        "R_LIBS_USER"                       
[33] "R_PAPERSIZE"                        "R_PDFVIEWER"                       
[35] "R_PLATFORM"                         "R_PRINTCMD"                        
[37] "R_QPDF"                             "R_RD4PDF"                          
[39] "R_SESSION_TMPDIR"                   "R_STRIP_SHARED_LIB"                
[41] "R_STRIP_STATIC_LIB"                 "R_TEXI2DVICMD"                     
[43] "R_UNZIPCMD"                         "R_ZIPCMD"                          
[45] "RSTUDIO_PANDOC"                     "RUST_BACKTRACE"                    
[47] "RUST_LOG"                           "SED"                               
[49] "SHELL"                              "SHLVL"                             
[51] "SSH_ASKPASS"                        "SSH_AUTH_SOCK"                     
[53] "SUDO_ASKPASS"                       "TAR"                               
[55] "TERM"                               "TERM_PROGRAM"                      
[57] "TERM_PROGRAM_VERSION"               "TMPDIR"                            
[59] "USER"                               "VSCODE_AMD_ENTRYPOINT"             
[61] "VSCODE_CODE_CACHE_PATH"             "VSCODE_CRASH_REPORTER_PROCESS_TYPE"
[63] "VSCODE_CWD"                         "VSCODE_GIT_ASKPASS_EXTRA_ARGS"     
[65] "VSCODE_GIT_ASKPASS_MAIN"            "VSCODE_GIT_ASKPASS_NODE"           
[67] "VSCODE_GIT_IPC_HANDLE"              "VSCODE_HANDLES_UNCAUGHT_ERRORS"    
[69] "VSCODE_IPC_HOOK"                    "VSCODE_NLS_CONFIG"                 
[71] "VSCODE_PID"                         "XDG_CACHE_HOME"                    
[73] "XDG_CONFIG_HOME"                    "XDG_DATA_HOME"                     
[75] "XPC_FLAGS"                          "XPC_SERVICE_NAME"                  
[77] "ZDOTDIR"                           

[[2]]
[1] "unknown"

[[3]]
[1] TRUE

[[4]]
[1] ""

I am also able to register new completions:

However, running the completion definition at https://github.com/posit-dev/ark/blob/398cfb945edb6d0be4552929c30e346c794ec517/crates/ark/src/modules/positron/completions.R#L76-L83 manually does not work:

If I insert a print statement into the callback for the Sys.getenv() completion, it does not print when I press tab. But it does for the cos() example above, so I guess the custom completion is not being called.

---

OK, after some digging, I find that the name argument being passed to the custom completion handler is x = NULL, not x, so the following does work:

I could PR this into ark, but I don't know if this is the desired setup, or something should change so that the name passed to the handler does not include default arguments. Also, why sign a contributor license agreement for 7 characters?

(While you're add it, I'd suggest adding a handler for Sys.unsetenv() 😉).

Were there any error messages in the UI, Output panel, or Developer Tools console?

No errors. Here is what appears in the "Positron Language Server: R 4.4.1" output pane when TAB is pressed after Sys.getenv(:

[Info  - 12:23:48 PM] Completion(
    CompletionParams {
        text_document_position: TextDocumentPositionParams {
            text_document: TextDocumentIdentifier {
                uri: Url {
                    scheme: "untitled",
                    cannot_be_a_base: true,
                    username: "",
                    password: None,
                    host: None,
                    port: None,
                    path: "Untitled-1",
                    query: None,
                    fragment: None,
                },
            },
            position: Position {
                line: 1,
                character: 11,
            },
        },
        work_done_progress_params: WorkDoneProgressParams {
            work_done_token: None,
        },
        partial_result_params: PartialResultParams {
            partial_result_token: None,
        },
        context: Some(
            CompletionContext {
                trigger_kind: Invoked,
                trigger_character: None,
            },
        ),
    },
)
[Info  - 12:23:48 PM] Completion context: DocumentContext {
    document: Document {
        contents: [
            "\nSys.getenv(\n\n",
        ],
        ast: {Tree {Node program (1, 0) - (3, 0)}},
    },
    node: {Node ( (1, 10) - (1, 11)},
    point: Point {
        row: 1,
        column: 11,
    },
    trigger: None,
}
[Info  - 12:23:48 PM] CompletionResolve(
    CompletionItem {
        label: "x = ",
        label_details: None,
        kind: Some(
            Field,
        ),
        detail: None,
        documentation: None,
        deprecated: None,
        preselect: None,
        sort_text: Some(
            "1-0-x",
        ),
        filter_text: Some(
            "x",
        ),
        insert_text: Some(
            "x = ",
        ),
        insert_text_format: Some(
            Snippet,
        ),
        insert_text_mode: None,
        text_edit: None,
        additional_text_edits: None,
        command: None,
        commit_characters: None,
        data: Some(
            Object {
                "Parameter": Object {
                    "name": String("x"),
                    "function": String("Sys.getenv"),
                },
            },
        ),
        tags: None,
    },
)

Here is what appears for Sys.setenv(:

[Info  - 12:25:33 PM] Completion(
    CompletionParams {
        text_document_position: TextDocumentPositionParams {
            text_document: TextDocumentIdentifier {
                uri: Url {
                    scheme: "untitled",
                    cannot_be_a_base: true,
                    username: "",
                    password: None,
                    host: None,
                    port: None,
                    path: "Untitled-1",
                    query: None,
                    fragment: None,
                },
            },
            position: Position {
                line: 1,
                character: 11,
            },
        },
        work_done_progress_params: WorkDoneProgressParams {
            work_done_token: None,
        },
        partial_result_params: PartialResultParams {
            partial_result_token: None,
        },
        context: Some(
            CompletionContext {
                trigger_kind: Invoked,
                trigger_character: None,
            },
        ),
    },
)
[Info  - 12:25:33 PM] Completion context: DocumentContext {
    document: Document {
        contents: [
            "\nSys.setenv()\n\n",
        ],
        ast: {Tree {Node program (1, 0) - (3, 0)}},
    },
    node: {Node ( (1, 10) - (1, 11)},
    point: Point {
        row: 1,
        column: 11,
    },
    trigger: None,
}
[Info  - 12:25:33 PM] CompletionResolve(
    CompletionItem {
        label: "COLORTERM",
        label_details: None,
        kind: None,
        detail: None,
        documentation: None,
        deprecated: None,
        preselect: None,
        sort_text: Some(
            "1-COLORTERM",
        ),
        filter_text: None,
        insert_text: Some(
            "COLORTERM = ",
        ),
        insert_text_format: Some(
            PlainText,
        ),
        insert_text_mode: None,
        text_edit: None,
        additional_text_edits: None,
        command: None,
        commit_characters: None,
        data: Some(
            String("Unknown"),
        ),
        tags: None,
    },
)

[DavisVaughan]

@noamross we will probably adjust the internals so that you really can just put "x" there rather than "x = NULL".

I think I know what the problem is though, it's likely related to our parser though so I'm happy to just handle this one if that's okay with you.

[testlabauto]

Verified Fixed

Positron Version(s) : 2024.09.0-95
OS Version          : OSX

Test scenario(s)

TAB presents list now with Sys.getenv(

Link(s) to TestRail test cases run or created: