add generate_surrogate_key macro throw deprecation warning in surroga…

…te key

macros/sql/generate_surrogate_key.sql

@@ -0,0 +1,56 @@
+{%- macro generate_surrogate_key(field_list) -%}
+    {# needed for safe_add to allow for non-keyword arguments see SO post #}
+    {# https://stackoverflow.com/questions/13944751/args-kwargs-in-jinja2-macros #}
+    {% set frustrating_jinja_feature = varargs %}
+    {{ return(adapter.dispatch('generate_surrogate_key', 'dbt_utils')(field_list, *varargs)) }}
+{% endmacro %}
+
+{%- macro default__generate_surrogate_key(field_list) -%}
+
+{%- if varargs|length >= 1 or field_list is string %}
+
+{%- set error_message = '
+Warning: the `surrogate_key` macro now takes a single list argument instead of \
+multiple string arguments. Support for multiple string arguments will be \
+deprecated in a future release of dbt-utils. The {}.{} model triggered this warning. \
+'.format(model.package_name, model.name) -%}
+
+{%- do exceptions.warn(error_message) -%}
+
+{# first argument is not included in varargs, so add first element to field_list_xf #}
+{%- set field_list_xf = [field_list] -%}
+
+{%- for field in varargs %}
+{%- set _ = field_list_xf.append(field) -%}
+{%- endfor -%}
+
+{%- else -%}
+
+{# if using list, just set field_list_xf as field_list #}
+{%- set field_list_xf = field_list -%}
+
+{%- endif -%}
+
+{% if var('surrogate_key_treat_nulls_as_empty_strings', False) %}
+    {% set default_null_value = "" %}
+{% else %}
+    {% set default_null_value = '_dbt_utils_surrogate_key_null_'%}
+{% endif %}
+
+{%- set fields = [] -%}
+
+{%- for field in field_list_xf -%}
+
+    {%- set _ = fields.append(
+        "coalesce(cast(" ~ field ~ " as " ~ type_string() ~ "), '" ~ default_null_value  ~"')"
+    ) -%}
+
+    {%- if not loop.last %}
+        {%- set _ = fields.append("'-'") -%}
+    {%- endif -%}
+
+{%- endfor -%}
+
+{{ hash(concat(fields)) }}
+
+{%- endmacro -%}

macros/sql/surrogate_key.sql

@@ -1,51 +1,19 @@
 {%- macro surrogate_key(field_list) -%}
-    {# needed for safe_add to allow for non-keyword arguments see SO post #}
-    {# https://stackoverflow.com/questions/13944751/args-kwargs-in-jinja2-macros #}
     {% set frustrating_jinja_feature = varargs %}
     {{ return(adapter.dispatch('surrogate_key', 'dbt_utils')(field_list, *varargs)) }}
 {% endmacro %}
 
 {%- macro default__surrogate_key(field_list) -%}
 
-{%- if varargs|length >= 1 or field_list is string %}
-
 {%- set error_message = '
-Warning: the `surrogate_key` macro now takes a single list argument instead of \
-multiple string arguments. Support for multiple string arguments will be \
-deprecated in a future release of dbt-utils. The {}.{} model triggered this warning. \
+Warning: the `dbt_utils.surrogate_key` macro has been fully deprecated in favor of \
+the new `generate_surrogate_key` macro. This new macro adjusts the default string value \
+passed to the coalesce function. To achieve parity with the original macro, \
+add a variable called `surrogate_key_treat_nulls_as_empty_strings` to your project with a \
+value of True. \
+The {}.{} model triggered this warning. \
 '.format(model.package_name, model.name) -%}
 
-{%- do exceptions.warn(error_message) -%}
-
-{# first argument is not included in varargs, so add first element to field_list_xf #}
-{%- set field_list_xf = [field_list] -%}
-
-{%- for field in varargs %}
-{%- set _ = field_list_xf.append(field) -%}
-{%- endfor -%}
-
-{%- else -%}
-
-{# if using list, just set field_list_xf as field_list #}
-{%- set field_list_xf = field_list -%}
-
-{%- endif -%}
-
-
-{%- set fields = [] -%}
-
-{%- for field in field_list_xf -%}
-
-    {%- set _ = fields.append(
-        "coalesce(cast(" ~ field ~ " as " ~ type_string() ~ "), '')"
-    ) -%}
-
-    {%- if not loop.last %}
-        {%- set _ = fields.append("'-'") -%}
-    {%- endif -%}
-
-{%- endfor -%}
-
-{{ hash(concat(fields)) }}
+{%- do exceptions.raise_compiler_error(error_message) -%}
 
 {%- endmacro -%}