Validate Shinylive app.json Structure — validate_app

Validates that a parsed app.json structure meets the requirements for a Shinylive application. Checks for proper list structure, required fields, and non-empty content. Provides detailed error messages when validation fails.

Usage

validate_app_json(json_data)

Arguments

json_data

List. Parsed JSON data from an app.json file. Should be a list where each element represents a file and contains:

name: Character string of the file name
content: Character string of the file content
type: Character string indicating the file type

Value

Logical TRUE if validation passes. If validation fails, throws an error with detailed information about the validation failure using cli_abort().

Validation Rules

The function checks these requirements:

json_data must be a list
json_data must contain at least one element
Each element must be a list (representing a file)
Each file list must contain all required fields:
- name
- content
- type

Error Messages

The function provides detailed error messages for these cases:

Not a list: "Expected a list or array of files"
Empty list: "File list is empty"
Invalid file entry: "Each entry must be a file object"
Missing fields: Lists specific missing required fields

Expected JSON Structure

The expected JSON structure is an array of objects, where each object represents a file in the application.

[
  {
    "name": "app.R",
    "content": "library(shiny)\n...",
    "type": "text"
  },
  {
    "name": "data/example.csv",
    "content": "x,y\n1,2\n...",
    "type": "text"
  }
]

Examples

if (FALSE) { # \dontrun{
# Valid structure
valid_data <- list(
  list(
    name = "app.R",
    content = "library(shiny)\n...",
    type = "text"
  ),
  list(
    name = "data.csv",
    content = "x,y\n1,2",
    type = "text"
  )
)
validate_app_json(valid_data)  # Returns TRUE

# Invalid structures that will error:
validate_app_json(list())  # Empty list
validate_app_json(list(
  list(name = "app.R")  # Missing required fields
))
} # }

Validate Shinylive `app.json` Structure