thinkr-open/golem/golem-fix-missing-ns

Check for Missing ns() in Modules

Validate that all module input/output IDs are properly namespaced.

Why Namespacing Matters

In Shiny modules, all input and output IDs must be namespaced using the ns() function. This prevents ID conflicts when the same module is used multiple times in an app.

Correct vs Incorrect

✅ Correct

mod_analytics_ui <- function(id) {
  ns <- NS(id)
  tagList(
    selectInput(
      ns("type_filter"),
      label = NULL,
      choices = c("All", "None")
    )
  )
}

❌ Incorrect

mod_analytics_ui <- function(id) {
  ns <- NS(id)
  tagList(
    selectInput(
      "type_filter",  # Missing ns()!
      label = NULL,
      choices = c("All", "None")
    )
  )
}

What to Check

In Module UI Functions

• All input IDs: textInput(), selectInput(), actionButton(), etc.
• All output IDs: plotOutput(), tableOutput(), uiOutput(), etc.
• All input control IDs used in ns() calls

In Module Server Functions

• JavaScript handler IDs that reference the module namespace
• observeEvent(input$...) references
• output$... definitions
• renderUI() generated element IDs

Places to Look

• Any file starting with mod_ in the R/ directory
• Both UI and server functions within modules

How Claude Checks

1. Locate all IDs in module files (files starting with mod_)

• Search for common patterns: Input(), Output(), input/output IDs

1. Verify namespacing by checking each ID is wrapped in ns()

• Exception: Only the first NS(id) definition doesn't need wrapping

1. Report findings

• If all IDs are properly namespaced: ✅ All good
• If missing IDs found: ❌ List them and ask for permission to fix

1. Fix if approved

• Wrap missing IDs in ns()
• Preserve code structure and formatting

Common Mistakes

When to Run

• After creating or modifying module UI functions
• Before running devtools::check()
• When adding new inputs/outputs to modules
• Before deploying to production

Example Workflow

User: Check my modules for missing ns()
 
Claude:
1. Scans all mod_*.R files
2. Identifies 3 missing ns() wrappings
3. Shows the issues with line numbers
4. Asks: "Should I fix these?"
 
User: Yes, fix them
 
Claude:
- Updates the files
- Runs the check again to verify
- Confirms: "All fixed! ✅"

Notes

• This check is for UI and reactive server code, not data processing functions
• Only module files (mod_*.R) need this check
• Regular functions (fct_*.R, utils_*.R) don't need namespace wrapping
• Module server functions are called with the module ID, which handles the namespacing