How to merge 2 dataframes and fill blank spaces with previous dataframe values in R

I have two datasets like the following:

df1:

df2:

I want to join the two dataframes by the gene_id column and fill the gene_name blanks with the corresponding gene_id.

The result I would like to obtain is as follows:

How could I get the above result in R preferably using dplyr (or tidyverse)?

I tried to use left_join, but in gene_name there are blank spaces not filled.

new_df <- left_join(df1, df2, by = "gene_id") 

>Solution :

After you do the join just use this. It will check for the empty values and place the gene_id for that row in gene_name:

new_df$gene_name <- ifelse(df$gene_name == '',df$gene_id,df$gene_name)