Adds assert_namespace calls to Appender initializers where appropriate;

skip print.Appender*() tests if not all required packages are available

Author: Stefan Fleck

DESCRIPTION

@@ -40,6 +40,7 @@ Suggests:
     rotor (>= 0.2.2),
     RPostgres,
     rprojroot,
+    RPushbullet,
     RSQLite,
     sendmailR,
     testthat,

NEWS.md

@@ -3,7 +3,8 @@
 ## new features
   * added `logger_tree()` which provides an overview of all registered loggers
   * added `print()` and `format()` methods for Appenders
-  * `AppenderMemory`: added `data` and `dt` active fields
+  * `AppenderMemory`: added `data` and `dt` active fields (which return the
+    log as a data.frame or data.table)
 
 ## API changes
   * Removed deprecated functions `FATAL()`, `ERROR()`. Use `lgr$fatal()`, 

R/Appender.R

@@ -419,6 +419,8 @@ AppenderJson <- R6::R6Class(
       layout = LayoutJson$new(),
       filters = NULL
     ){
+      assert_namespace("jsonlite")
+
       self$set_file(file)
       self$set_threshold(threshold)
       self$set_layout(layout)
@@ -655,6 +657,7 @@ AppenderDt <- R6::R6Class(
       buffer_size = 1e5,
       filters = NULL
     ){
+      assert_namespace("data.table")
       assert(is_scalar_integerish(buffer_size))
       assert(
         data.table::is.data.table(prototype) && is.integer(prototype$.id),
@@ -1948,6 +1951,8 @@ AppenderPushbullet <- R6::R6Class(
       apikey = NULL,
       filters = NULL
     ){
+      assert_namespace("RPushbullet")
+
       private$initialize_buffer(buffer_size)
       self$set_flush_on_rotate(FALSE)
       self$set_flush_on_exit(FALSE)

tests/testthat/test_print_Appender.R

@@ -4,6 +4,16 @@ context("print_Appender")
 
 
 test_that("all Appenders print() without failure", {
+  if (
+    !requireNamespace("sendmailR") ||
+    !requireNamespace("RPushbullet") ||
+    !requireNamespace("rotor") ||
+    !requireNamespace("DBI") ||
+    !requireNamespace("RSQLite")
+  ){
+    skip("Required packages not installed")
+  }
+
   tf <- tempfile()
   on.exit(unlink(tf))