From 73641476283bbb257e598f5d80813e50b977989b Mon Sep 17 00:00:00 2001
From: Tuomas Borman <60338854+TuomasBorman@users.noreply.github.com>
Date: Thu, 7 Mar 2024 17:24:19 +0200
Subject: [PATCH] Fix merging of lists (#18)

---
 R/utils.R | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/R/utils.R b/R/utils.R
index d1aa386..74e11b5 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -390,12 +390,23 @@
 # data.frame
 #' @importFrom dplyr full_join
 .full_join_list <- function(res){
-    df <- Reduce(function(df1, df2){
-        # Get common columns
-        common_cols <- intersect(colnames(df1), colnames(df2))
-        # Merge based on common columns
-        temp <- full_join(df1, df2, by = common_cols)
-        return(temp)
-    }, res)
+    # Remove empty elements
+    res <- res[ lengths(res) > 0 ]
+    # If there is more than one element, merge them
+    if( length(res) > 1 ){
+        df <- Reduce(function(df1, df2){
+            # Get common columns
+            common_cols <- intersect(colnames(df1), colnames(df2))
+            # Merge based on common columns
+            temp <- full_join(df1, df2, by = common_cols)
+            return(temp)
+        }, res)
+    } else if( length(res) == 1 ){
+        # Otherwise if there is only one element, give the element
+        df <- res[[1]]
+    } else{
+        # If all the data.frames were without information, give NULL
+        df <- NULL
+    }
     return(df)
 }