Improve error handling and code style in R functions

Refactored multiple R scripts to use more robust tryCatch error handling, improved code formatting, and enhanced user feedback for error cases. These changes increase reliability and maintainability across gen_docs, gen_image, gen_tests, setEnv, setAPI, vertex, and utility functions.

Author: jhk0530

R/gemini_narrative.R

@@ -40,7 +40,7 @@ gemini_narrative <- function(input, type = "table", prompt = NULL, ...) {
       input,
       format = "pipe",
       col.names = colnames(input)
-    ), collapse = '\n')
+    ), collapse = "\n")
     # Use user prompt if provided, otherwise use default
     if (is.null(prompt)) {
       # Default prompt for table with a newline before the table
@@ -58,8 +58,8 @@ gemini_narrative <- function(input, type = "table", prompt = NULL, ...) {
   } else if (type == "figure") {
     # Check if input is a valid image file path and a scalar string
     if (!is.character(input) || length(input) != 1 ||
-        !file.exists(input) ||
-        !(tools::file_ext(input) %in% c("png", "jpeg", "jpg", "webp", "heic", "heif"))) {
+      !file.exists(input) ||
+      !(tools::file_ext(input) %in% c("png", "jpeg", "jpg", "webp", "heic", "heif"))) {
       stop("Input must be a single valid image file path (png, jpeg, jpg, webp, heic, heif) when type is 'figure'.")
     }
     # Determine image type

R/gen_docs.R

@@ -3,17 +3,17 @@
 #' @description Generates Roxygen2 documentation for an R function based on the currently selected code.
 #'
 #' @param prompt  A character string specifying additional instructions for the LLM.  Defaults to a prompt requesting Roxygen2 documentation without the original code.
-#' 
+#'
 #' @return Invisibly returns the generated documentation string, but primarily inserts the text into the RStudio console.
 #' @examples
 #' \dontrun{
 #' # Select your function code in the editor, then run:
 #' gen_docs()
-#' 
+#'
 #' # For custom instructions:
 #' gen_docs("Generate minimal Roxygen docs for this function")
 #' }
-#' 
+#'
 #' @importFrom rstudioapi getActiveDocumentContext executeCommand insertText
 #' @importFrom cli cli_alert_danger cli_status cli_status_clear
 #' @export
@@ -30,7 +30,7 @@ gen_docs <- function(prompt = NULL) {
 
   context <- getActiveDocumentContext()
   selectedCode <- context$selection[[1]]$text
-  
+
   # Check if code is selected
   if (nchar(trim(selectedCode)) == 0) {
     cli_alert_danger("No code selected. Please select an R function to document.")
@@ -39,42 +39,44 @@ gen_docs <- function(prompt = NULL) {
 
   # Show status message
   sb <- cli_status("Generating Roxygen documentation...")
-  
+
   # API call and error handling
-  description <- tryCatch({
-    result <- gemini(
-      prompt = paste0(
-        prompt,
-        "\n---",
-        selectedCode
+  description <- tryCatch(
+    {
+      result <- gemini(
+        prompt = paste0(
+          prompt,
+          "\n---",
+          selectedCode
+        )
       )
-    )
-    
-    if (is.null(result) || length(result) == 0 || nchar(trim(result)) == 0) {
+
+      if (is.null(result) || length(result) == 0 || nchar(trim(result)) == 0) {
+        cli_status_clear(id = sb)
+        cli_alert_danger("Failed to generate documentation or received empty response.")
+        return(invisible(NULL))
+      }
+
+      result
+    },
+    error = function(e) {
       cli_status_clear(id = sb)
-      cli_alert_danger("Failed to generate documentation or received empty response.")
+      cli_alert_danger(paste0("Error generating documentation: ", e$message))
       return(invisible(NULL))
     }
-    
-    result
-  }, 
-  error = function(e) {
-    cli_status_clear(id = sb)
-    cli_alert_danger(paste0("Error generating documentation: ", e$message))
-    return(invisible(NULL))
-  })
-  
+  )
+
   # Early exit if error occurred
   if (is.null(description)) {
     return(invisible(NULL))
   }
-  
+
   cli_status_clear(id = sb)
-  
+
   # Insert result into console if available
   executeCommand("activateConsole")
   insertText(text = description)
-  
+
   # Return generated documentation invisibly
   return(invisible(description))
 }

R/gen_image.R

@@ -33,7 +33,7 @@ gen_image <- function(prompt, filename = "gemini_image.png", overwrite = TRUE,
   if (!validate_params(prompt, model, temperature, topP, topK, seed, api_key = TRUE)) {
     return(NULL)
   }
-  
+
   # Check if the model is for image generation
   if (model != "2.0-flash-exp-image-generation") {
     cli_alert_danger("Error: For image generation, model must be '2.0-flash-exp-image-generation'")
@@ -48,59 +48,65 @@ gen_image <- function(prompt, filename = "gemini_image.png", overwrite = TRUE,
 
   # Generate the image
   sb <- cli_status("Generating image with Gemini...")
-  
+
   # 2. Add error handling for response
-  response <- tryCatch({
-    gemini(
-      prompt = prompt, 
-      model = model, 
-      temperature = temperature, 
-      maxOutputTokens = maxOutputTokens,
-      topK = topK,
-      topP = topP,
-      seed = seed
-    )
-  }, error = function(e) {
-    cli_status_clear(id = sb)
-    cli_alert_danger(paste("Error generating image:", e$message))
-    return(NULL)
-  })
-  
+  response <- tryCatch(
+    {
+      gemini(
+        prompt = prompt,
+        model = model,
+        temperature = temperature,
+        maxOutputTokens = maxOutputTokens,
+        topK = topK,
+        topP = topP,
+        seed = seed
+      )
+    },
+    error = function(e) {
+      cli_status_clear(id = sb)
+      cli_alert_danger(paste("Error generating image:", e$message))
+      return(NULL)
+    }
+  )
+
   # 3. Handle case when response is NULL
   if (is.null(response)) {
     cli_status_clear(id = sb)
     cli_alert_danger("Failed to generate image - no response received")
     return(NULL)
   }
-  
+
   cli_status_clear(id = sb)
 
   # 4. Add validation for response structure
   if (length(response) < 2) {
     cli_alert_danger("Invalid response format - missing image data")
     return(NULL)
   }
-  
+
   # 5. Improve error handling for file saving
-  tryCatch({
-    # Extract image data part (second element)
-    base64_data <- response[2]
-    
-    # Add check for empty data
-    if (is.null(base64_data) || nchar(base64_data) == 0) {
-      cli_alert_danger("Empty image data received")
+  tryCatch(
+    {
+      # Extract image data part (second element)
+      base64_data <- response[2]
+
+      # Add check for empty data
+      if (is.null(base64_data) || nchar(base64_data) == 0) {
+        cli_alert_danger("Empty image data received")
+        return(NULL)
+      }
+
+      # Base64 decode
+      image_data <- base64enc::base64decode(base64_data)
+
+      # Write file
+      writeBin(image_data, filename)
+      cli_alert_success(paste("Image saved to", filename))
+      return(filename)
+    },
+    error = function(e) {
+      cli_alert_danger(paste("Error saving image:", e$message))
       return(NULL)
     }
-    
-    # Base64 decode
-    image_data <- base64enc::base64decode(base64_data)
-    
-    # Write file
-    writeBin(image_data, filename)
-    cli_alert_success(paste("Image saved to", filename))
-    return(filename)
-  }, error = function(e) {
-    cli_alert_danger(paste("Error saving image:", e$message))
-    return(NULL)
-  })
+  )
 }

R/gen_tests.R

@@ -11,7 +11,7 @@
 #' \dontrun{
 #' # Select your function code in the editor, then run:
 #' gen_tests()
-#' 
+#'
 #' # For custom instructions:
 #' gen_tests("Generate comprehensive testthat tests with edge cases")
 #' }
@@ -32,19 +32,22 @@ gen_tests <- function(prompt = NULL) {
   }
 
   # Get selected code from the editor
-  context <- tryCatch({
-    getActiveDocumentContext()
-  }, error = function(e) {
-    cli_alert_danger("Failed to get active document context: ", e$message)
-    return(NULL)
-  })
-  
+  context <- tryCatch(
+    {
+      getActiveDocumentContext()
+    },
+    error = function(e) {
+      cli_alert_danger("Failed to get active document context: ", e$message)
+      return(NULL)
+    }
+  )
+
   if (is.null(context)) {
     return(invisible(NULL))
   }
-  
+
   selectedCode <- context$selection[[1]]$text
-  
+
   # Check if code is selected
   if (is.null(selectedCode) || nchar(trim(selectedCode)) == 0) {
     cli_alert_danger("No code selected. Please select an R function to generate tests for.")
@@ -53,46 +56,51 @@ gen_tests <- function(prompt = NULL) {
 
   # Show status message
   sb <- cli_status("Generating unit tests...")
-  
+
   # API call and error handling
-  test_code <- tryCatch({
-    result <- gemini(
-      prompt = paste0(
-        prompt,
-        "\n---\n",
-        selectedCode
+  test_code <- tryCatch(
+    {
+      result <- gemini(
+        prompt = paste0(
+          prompt,
+          "\n---\n",
+          selectedCode
+        )
       )
-    )
-    
-    if (is.null(result) || length(result) == 0 || nchar(trim(result)) == 0) {
+
+      if (is.null(result) || length(result) == 0 || nchar(trim(result)) == 0) {
+        cli_status_clear(id = sb)
+        cli_alert_danger("Failed to generate test code or received empty response.")
+        return(invisible(NULL))
+      }
+
+      result
+    },
+    error = function(e) {
       cli_status_clear(id = sb)
-      cli_alert_danger("Failed to generate test code or received empty response.")
+      cli_alert_danger(paste0("Error generating test code: ", e$message))
       return(invisible(NULL))
     }
-    
-    result
-  }, 
-  error = function(e) {
-    cli_status_clear(id = sb)
-    cli_alert_danger(paste0("Error generating test code: ", e$message))
-    return(invisible(NULL))
-  })
-  
+  )
+
   # Early exit if error occurred
   if (is.null(test_code)) {
     return(invisible(NULL))
   }
-  
+
   cli_status_clear(id = sb)
-  
+
   # Insert test code into the console
-  tryCatch({
-    executeCommand("activateConsole")
-    insertText(text = test_code)
-  }, error = function(e) {
-    cli_alert_danger(paste0("Failed to insert text into console: ", e$message))
-  })
-  
+  tryCatch(
+    {
+      executeCommand("activateConsole")
+      insertText(text = test_code)
+    },
+    error = function(e) {
+      cli_alert_danger(paste0("Failed to insert text into console: ", e$message))
+    }
+  )
+
   # Return generated test code invisibly
   return(invisible(test_code))
 }

R/setAPI.R

@@ -19,13 +19,13 @@ setAPI <- function(api_key) {
     cli_alert_danger("API key must be a non-empty string.")
     return(invisible())
   }
-  
+
   # Check typical API key length (Google API keys are usually 39 characters)
   if (nchar(api_key) < 10) {
     cli_alert_danger("API key seems too short. Please verify your key.")
     return(invisible())
   }
-  
+
   # Safely display only the last part of the API key
   last_chars <- 4
   if (nchar(api_key) > last_chars) {
@@ -34,7 +34,7 @@ setAPI <- function(api_key) {
     # If the API key is too short, show only the last character
     last <- substr(api_key, nchar(api_key), nchar(api_key))
   }
-  
+
   # Set environment variable
   Sys.setenv(GEMINI_API_KEY = api_key)
 
@@ -44,6 +44,6 @@ setAPI <- function(api_key) {
   cli_end()
 
   cli_alert("You may try {.run gemini_chat('What is CRAN?')}")
-  
+
   return(invisible())
 }