From c2e79f4b0df0500ad3680940aa97ac8d732dc5aa Mon Sep 17 00:00:00 2001
From: jwildfire <jwildfire@gmail.com>
Date: Mon, 22 Apr 2019 07:29:26 -0700
Subject: [PATCH] allow null in hasField/Column checks. fix #240

---
 R/hasColumn.R                   | 11 ++++++++---
 R/hasField.R                    | 22 +++++++++++++---------
 tests/testthat/test_hasColumn.R |  5 ++++-
 tests/testthat/test_hasField.R  |  3 +++
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/R/hasColumn.R b/R/hasColumn.R
index d64fc52d..b1149dc1 100644
--- a/R/hasColumn.R
+++ b/R/hasColumn.R
@@ -14,10 +14,15 @@
 
 hasColumn <- function(columnName, data){
   stopifnot(
-    typeof(columnName)=="character",
-    length(columnName)==1,
+    typeof(columnName)=="character" || is.null(columnName),
+    length(columnName)==1  || is.null(columnName),
     is.data.frame(data)
   )
   
-  return(toupper(columnName) %in% toupper(colnames(data)))
+  if(is.null(columnName)){
+    return(FALSE)
+  } else {
+    return(toupper(columnName) %in% toupper(colnames(data)))  
+  }
+  
 }
diff --git a/R/hasField.R b/R/hasField.R
index ab038568..f4612c6a 100644
--- a/R/hasField.R
+++ b/R/hasField.R
@@ -16,18 +16,22 @@
 hasField<- function(fieldValue, columnName, data){
   stopifnot(
     length(fieldValue)==1,
-    typeof(columnName)=="character",
-    length(columnName)==1,
+    typeof(columnName)=="character" || is.null(columnName),
+    length(columnName)==1  || is.null(columnName), 
     is.data.frame(data)
   )
 
-  columnFound <- hasColumn(columnName=columnName, data=data)
-  if(columnFound){
+  if(is.null(columnName)){
+    return(FALSE)
+  } else {
+    columnFound <- hasColumn(columnName=columnName, data=data)
+    if(columnFound){
+      validFields <- unique(data[[columnName]])
+    } else{
+      validFields <- c()
+    }
+
     validFields <- unique(data[[columnName]])
-  } else{
-    validFields <- c()
+    return(fieldValue %in% validFields)
   }
-
-  validFields <- unique(data[[columnName]])
-  return(fieldValue %in% validFields)
 }
diff --git a/tests/testthat/test_hasColumn.R b/tests/testthat/test_hasColumn.R
index 5145492b..4751ebc8 100644
--- a/tests/testthat/test_hasColumn.R
+++ b/tests/testthat/test_hasColumn.R
@@ -13,7 +13,10 @@ test_that("columns are found when expected",{
   # returns false when fieldValue isn't there or there is a type mismatch
   expect_false(hasColumn(columnName="PARAMETER",data=adlbc))
   expect_false(hasColumn(columnName="SUBJID2",data=adlbc))
-
+  
+  # returns false for null columnName
+  expect_false(hasColumn(columnName=NULL,data=adlbc))
+  
   # fails with invalid parameters
   expect_error(hasColumn(columnName=123,data=adlbc))
   expect_error(hasColumn(columnName=c("PARAM","SUBJID"),data=adlbc))
diff --git a/tests/testthat/test_hasField.R b/tests/testthat/test_hasField.R
index a1e9197e..7c18ed53 100644
--- a/tests/testthat/test_hasField.R
+++ b/tests/testthat/test_hasField.R
@@ -20,6 +20,9 @@ test_that("fields are found when expected",{
   expect_false(hasField(fieldValue="Not_a_real_value",columnName="PARAM",data=adlbc))
   expect_false(hasField(fieldValue=12,columnName="PARAM",data=adlbc))
 
+  # returns false for null columnName
+  expect_false(hasField(fieldValue="Bilirubin (umol/L)",columnName=NULL,data=adlbc))
+  
   # fails with invalid parameters
   expect_error(hasField(fieldValue="Bilirubin (umol/L)",columnName=c("PARAM","ID"),data=adlbc))
   expect_error(hasField(columnName="PARAM",data=list(adlbc))) #fieldValue missing