[R-package][ci] Added more R linters (fixes #2477) (#2533)

* Added more linters on R code

* started working on implicit integers

* finished style changes to handle implicit integers

* regenned documentation and added concatenation linter

* changed channel for r-lintr

* try building stringi before lintr

* trying to get libicui18n

* trying another thing

* trying conda-forge again

* added re-install of stringi

* uncommented other stages

* Update .ci/test.sh

Co-Authored-By: Nikita Titov <nekit94-08@mail.ru>

* removed apt update and changed lintr version floor

* get lintr from CRAN

* R needs to come before C++ linting

* testing lintr install from CRAN

* trying one more thing

* more verbose

* order might matter

* removed commented code

* cleaned up linting block in test.sh

* grouped conda install calls and fixed a few integer array things

.ci/lint_r_code.R

@@ -4,7 +4,7 @@ library(lintr)
 args <- commandArgs(
     trailingOnly = TRUE
 )
-SOURCE_DIR <- args[[1]]
+SOURCE_DIR <- args[[1L]]
 
 FILES_TO_LINT <- list.files(
     path = SOURCE_DIR
@@ -17,22 +17,34 @@ FILES_TO_LINT <- list.files(
 )
 
 LINTERS_TO_USE <- list(
-    "closed_curly" = lintr::closed_curly_linter
+    "assignment" = lintr::assignment_linter
+    , "closed_curly" = lintr::closed_curly_linter
+    , "equals_na" = lintr::equals_na_linter
+    , "function_left" = lintr::function_left_parentheses_linter
+    , "commas" = lintr::commas_linter
+    , "concatenation" = lintr::unneeded_concatenation_linter
+    , "implicit_integers" = lintr::implicit_integer_linter
     , "infix_spaces" = lintr::infix_spaces_linter
-    , "long_lines" = lintr::line_length_linter(length = 120)
+    , "long_lines" = lintr::line_length_linter(length = 120L)
     , "tabs" = lintr::no_tab_linter
     , "open_curly" = lintr::open_curly_linter
+    , "paren_brace_linter" = lintr::paren_brace_linter
+    , "semicolon" = lintr::semicolon_terminator_linter
+    , "seq" = lintr::seq_linter
+    , "single_quotes" = lintr::single_quotes_linter
     , "spaces_inside" = lintr::spaces_inside_linter
     , "spaces_left_parens" = lintr::spaces_left_parentheses_linter
+    , "todo_comments" = lintr::todo_comment_linter
     , "trailing_blank" = lintr::trailing_blank_lines_linter
     , "trailing_white" = lintr::trailing_whitespace_linter
+    , "true_false" = lintr::T_and_F_symbol_linter
 )
 
 cat(sprintf("Found %i R files to lint\n", length(FILES_TO_LINT)))
 
-results <- c()
+results <- NULL
 
-for (r_file in FILES_TO_LINT){
+for (r_file in FILES_TO_LINT) {
 
     this_result <- lintr::lint(
         filename = r_file
@@ -52,7 +64,7 @@ for (r_file in FILES_TO_LINT){
 
 issues_found <- length(results)
 
-if (issues_found > 0){
+if (issues_found > 0L) {
     cat("\n")
     print(results)
 }

.ci/test.sh

@@ -50,11 +50,14 @@ if [[ $TRAVIS == "true" ]] && [[ $TASK == "check-docs" ]]; then
     exit 0
 fi
 
-if [[ $TASK == "lint" ]]; then
+if [[ $TRAVIS == "true" ]] && [[ $TASK == "lint" ]]; then
     conda install -q -y -n $CONDA_ENV \
         pycodestyle \
         pydocstyle \
-        r-lintr
+        r-stringi  # stringi needs to be installed separate from r-lintr to avoid issues like 'unable to load shared object stringi.so'
+    conda install -q -y -n $CONDA_ENV \
+        -c conda-forge \
+            r-lintr>=2.0
     pip install --user cpplint
     echo "Linting Python code"
     pycodestyle --ignore=E501,W503 --exclude=./compute,./.nuget . || exit -1

R-package/R/aliases.R

@@ -5,7 +5,7 @@
 #               lazy evaluation (so it doesn't matter what order R sources files during installation).
 # [return] A named list, where each key is a main LightGBM parameter and each value is a character
 #          vector of corresponding aliases.
-.PARAMETER_ALIASES <- function(){
+.PARAMETER_ALIASES <- function() {
     return(list(
         "boosting" = c(
             "boosting"

R-package/R/callback.R

@@ -9,7 +9,7 @@ CB_ENV <- R6::R6Class(
     end_iteration = NULL,
     eval_list = list(),
     eval_err_list = list(),
-    best_iter = -1,
+    best_iter = -1L,
     best_score = NA,
     met_early_stop = FALSE
   )
@@ -30,7 +30,7 @@ cb.reset.parameters <- function(new_params) {
   init <- function(env) {
 
     # Store boosting rounds
-    nrounds <<- env$end_iteration - env$begin_iteration + 1
+    nrounds <<- env$end_iteration - env$begin_iteration + 1L
 
     # Check for model environment
     if (is.null(env$model)) { stop("Env should have a ", sQuote("model")) }
@@ -60,7 +60,7 @@ cb.reset.parameters <- function(new_params) {
       if (is.function(p)) {
 
         # Check if requires at least two arguments
-        if (length(formals(p)) != 2) {
+        if (length(formals(p)) != 2L) {
           stop("Parameter ", sQuote(n), " is a function but not of two arguments")
         }
 
@@ -117,7 +117,7 @@ cb.reset.parameters <- function(new_params) {
 format.eval.string <- function(eval_res, eval_err = NULL) {
 
   # Check for empty evaluation string
-  if (is.null(eval_res) || length(eval_res) == 0) {
+  if (is.null(eval_res) || length(eval_res) == 0L) {
     stop("no evaluation results")
   }
 
@@ -133,15 +133,15 @@ format.eval.string <- function(eval_res, eval_err = NULL) {
 merge.eval.string <- function(env) {
 
   # Check length of evaluation list
-  if (length(env$eval_list) <= 0) {
+  if (length(env$eval_list) <= 0L) {
     return("")
   }
 
   # Get evaluation
   msg <- list(sprintf("[%d]:", env$iteration))
 
   # Set if evaluation error
-  is_eval_err <- length(env$eval_err_list) > 0
+  is_eval_err <- length(env$eval_err_list) > 0L
 
   # Loop through evaluation list
   for (j in seq_along(env$eval_list)) {
@@ -162,25 +162,25 @@ merge.eval.string <- function(env) {
 
 }
 
-cb.print.evaluation <- function(period = 1) {
+cb.print.evaluation <- function(period = 1L) {
 
   # Create callback
   callback <- function(env) {
 
     # Check if period is at least 1 or more
-    if (period > 0) {
+    if (period > 0L) {
 
       # Store iteration
       i <- env$iteration
 
       # Check if iteration matches moduo
-      if ( (i - 1) %% period == 0 || is.element(i, c(env$begin_iteration, env$end_iteration))) {
+      if ((i - 1L) %% period == 0L || is.element(i, c(env$begin_iteration, env$end_iteration))) {
 
         # Merge evaluation string
         msg <- merge.eval.string(env)
 
         # Check if message is existing
-        if (nchar(msg) > 0) {
+        if (nchar(msg) > 0L) {
           cat(merge.eval.string(env), "\n")
         }
 
@@ -205,15 +205,15 @@ cb.record.evaluation <- function() {
   callback <- function(env) {
 
     # Return empty if empty evaluation list
-    if (length(env$eval_list) <= 0) {
+    if (length(env$eval_list) <= 0L) {
       return()
     }
 
     # Set if evaluation error
-    is_eval_err <- length(env$eval_err_list) > 0
+    is_eval_err <- length(env$eval_err_list) > 0L
 
     # Check length of recorded evaluation
-    if (length(env$model$record_evals) == 0) {
+    if (length(env$model$record_evals) == 0L) {
 
       # Loop through each evaluation list element
       for (j in seq_along(env$eval_list)) {
@@ -290,7 +290,7 @@ cb.early.stop <- function(stopping_rounds, verbose = TRUE) {
     eval_len <<- length(env$eval_list)
 
     # Early stopping cannot work without metrics
-    if (eval_len == 0) {
+    if (eval_len == 0L) {
       stop("For early stopping, valids must have at least one element")
     }
 
@@ -301,7 +301,7 @@ cb.early.stop <- function(stopping_rounds, verbose = TRUE) {
 
     # Maximization or minimization task
     factor_to_bigger_better <<- rep.int(1.0, eval_len)
-    best_iter <<- rep.int(-1, eval_len)
+    best_iter <<- rep.int(-1L, eval_len)
     best_score <<- rep.int(-Inf, eval_len)
     best_msg <<- list()