From 1c3934a15d969b253d3bc1cf1f36d92b09f4d39c Mon Sep 17 00:00:00 2001
From: Tristan Handy <jthandy@gmail.com>
Date: Tue, 26 Feb 2019 10:43:13 -0500
Subject: [PATCH] made changes to right() function

---
 .../data/cross_db/data_right.csv              |  3 ++-
 .../models/cross_db_utils/test_right.sql      |  2 +-
 macros/cross_db_utils/right.sql               | 25 ++++++++++++++++---
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/integration_tests/data/cross_db/data_right.csv b/integration_tests/data/cross_db/data_right.csv
index a9b5cc06..63af8e6a 100644
--- a/integration_tests/data/cross_db/data_right.csv
+++ b/integration_tests/data/cross_db/data_right.csv
@@ -1,4 +1,5 @@
 string_text,length_expression,output
 abcdef,3,def
 fishtown,4,town
-december,5,ember
\ No newline at end of file
+december,5,ember
+december,0,
\ No newline at end of file
diff --git a/integration_tests/models/cross_db_utils/test_right.sql b/integration_tests/models/cross_db_utils/test_right.sql
index 249bbbe8..eaad4f4f 100644
--- a/integration_tests/models/cross_db_utils/test_right.sql
+++ b/integration_tests/models/cross_db_utils/test_right.sql
@@ -7,6 +7,6 @@ with data as (
 select
 
     {{ dbt_utils.right('string_text', 'length_expression') }} as actual,
-    output as expected
+    coalesce(output, '') as expected
 
 from data
\ No newline at end of file
diff --git a/macros/cross_db_utils/right.sql b/macros/cross_db_utils/right.sql
index dc760cfb..5a2d5226 100644
--- a/macros/cross_db_utils/right.sql
+++ b/macros/cross_db_utils/right.sql
@@ -13,9 +13,26 @@
 
 {% macro bigquery__right(string_text, length_expression) %}
 
-    substr(
-        {{ string_text }},
-        -1 * ({{ length_expression }})
-    )
+    case when {{ length_expression }} = 0 
+        then ''
+    else 
+        substr(
+            {{ string_text }},
+            -1 * ({{ length_expression }})
+        )
+    end
+
+{%- endmacro -%}
+
+{% macro snowflake__right(string_text, length_expression) %}
+
+    case when {{ length_expression }} = 0 
+        then ''
+    else 
+        right(
+            {{ string_text }},
+            {{ length_expression }}
+        )
+    end
 
 {%- endmacro -%}
\ No newline at end of file