Use lintr to test that endian is always specified

Author: Bisaloo

.lintr

@@ -10,6 +10,7 @@ linters: linters_with_tags(
     object_usage_linter = NULL,
     commented_code_linter = NULL,
     indentation_linter = NULL,
-    nonportable_path_linter = NULL
+    nonportable_path_linter = NULL,
+    endian_linter = lightr:::endian_linter()
   )
 

DESCRIPTION

@@ -27,6 +27,7 @@ Imports:
 Suggests:
     digest,
     knitr,
+    lintr,
     pavo,
     rmarkdown,
     spelling,

R/endian_linter.R

@@ -0,0 +1,27 @@
+endian_linter <- function() {
+  xpath <- "
+    //SYMBOL_FUNCTION_CALL[text() = 'readBin' or text() = 'writeBin']
+      /parent::expr
+      /parent::expr[not(SYMBOL_SUB[text() = 'endian'])]
+  "
+
+  lintr::Linter(function(source_expression) {
+    if (!lintr::is_lint_level(source_expression, "expression")) {
+      return(list())
+    }
+
+    xml <- source_expression$xml_parsed_content
+
+    bad_expr <- xml2::xml_find_all(xml, xpath)
+
+    lintr::xml_nodes_to_lints(
+      bad_expr,
+      source_expression = source_expression,
+      lint_message = paste(
+        xml2::xml_find_first(bad_expr, "string(.//SYMBOL_FUNCTION_CALL)"),
+        "should always include a value for 'endian'"
+      ),
+      type = "warning"
+    )
+  })
+}