Add expect_no_rows macro

Author: psousa50

README.md

@@ -154,6 +154,23 @@ UNION ALL
 {% endcall %}
 ```
 
+### Expectations
+
+The expectations are the results you expect from the model. The framework compares the expectations with the actuals and shows the differences in the test report.
+
+```jinja
+{% call dbt_unit_testing.expect() %}
+  select ...
+{% endcall %}
+```
+
+You can use the macro `expect_no_rows` to test if the model returns no rows:
+
+```jinja
+{% call dbt_unit_testing.expect_no_rows() %}
+{% endcall %}
+```
+
 ## Running tests
 
 The framework leverages the dbt test command to run the tests. You can run all the tests in your project with the following command:
@@ -170,12 +187,13 @@ dbt test --select tag:unit-test
 
 ## Available Macros
 
-| macro name                   | description                                     |
-|------------------------------|-------------------------------------------------|
-| dbt_unit_testing.test        | Defines a Test                                  |
-| dbt_unit_testing.mock_ref    | Mocks a **model** / **snapshot** / **seed**     |
-| dbt_unit_testing.mock_source | Mocks a **source**                              |
-| dbt_unit_testing.expect      | Defines Test expectations                       |
+| macro name                      | description                                     |
+|---------------------------------|-------------------------------------------------|
+| dbt_unit_testing.test           | Defines a Test                                  |
+| dbt_unit_testing.mock_ref       | Mocks a **model** / **snapshot** / **seed**     |
+| dbt_unit_testing.mock_source    | Mocks a **source**                              |
+| dbt_unit_testing.expect         | Defines the Test expectations                   |
+| dbt_unit_testing.expect_no_rows | Used to test if the model returns no rows       |
 
 ## Test Examples
 
@@ -701,6 +719,7 @@ In this example, the `activity_details` column, which is a struct, is transforme
 | **count_column**        | The name of the `count` column in the test report        | count| project/test            |
 | **run_as_incremental**      | Runs the model in `incremental` mode (it has no effect if the model is not incremental)     | false| project/test            |
 | **column_transformations**      | A JSON structure specifying the desired transformations for each column. See [Column Transformations](#column-transformations) for more details.     | {}| project/test            |
+| last_spaces_replace_char | Replace the spaces at the end of the values with another character. See [Test Feedback](#test-feedback) for more details. | (space) | project/test |
 
 Notes:
 
@@ -740,6 +759,28 @@ Rows mismatch:
 
 The first line was not on the model, but the second line was.
 
+### Spaces at the end of the diff values
+
+It can be hard to spot the difference when the values have spaces at the end. To avoid this, you can use the option `last_spaces_replace_char` to replace the spaces at the end of the values with another character:
+
+```yaml
+vars:
+  unit_tests_config:
+    last_spaces_replace_char: "."
+```
+
+This will replace the spaces at the end of the values with a dot. The result will be displayed like this:
+
+```yaml
+MODEL: customers
+TEST:  should sum order values to calculate customer_lifetime_value
+Rows mismatch:
+| diff | count | some_column |
+| ---- | ----- | ----------- |
+| +    |     1 | John        |
+| -    |     1 | John..      |
+```
+
 # Known Limitations
 
 - You can not have a *model* with the same name as a *source* or a *seed* (unless you set the *use_qualified_sources* option to *true*).

integration-tests/tests/unit/expect_no_rows.sql

@@ -0,0 +1,13 @@
+{{
+    config(
+        tags=['unit-test', 'bigquery', 'snowflake', 'postgres']
+    )
+}}
+
+{% call dbt_unit_testing.test('model_b_references_a', 'sample test') %}
+  {% call dbt_unit_testing.mock_ref ('model_a') %}
+    select 0 as a, 'a' as b
+  {% endcall %}
+  {% call dbt_unit_testing.expect_no_rows() %}
+  {% endcall %}
+{% endcall %}

macros/mock_builders.sql

@@ -53,6 +53,17 @@
   {{ return (dbt_unit_testing.append_json(expectations)) }}
 {% endmacro %}
 
+{% macro expect_no_rows(options={}) %}
+  {% set dummy = caller() %}
+  {% set expectations = {
+      "type": "expectations",
+      "options": options,
+      "input_values": "select a from (select 1 as a) as s where false",
+    }
+  %} 
+  {{ return (dbt_unit_testing.append_json(expectations)) }}
+{% endmacro %}
+
 {% macro append_json(json) %}
   {{ return (json | tojson() ~ '####_JSON_LINE_DELIMITER_####') }}
 {% endmacro %}

macros/output.sql

@@ -1,4 +1,4 @@
-{% macro print_table(agate_table) %}
+{% macro print_table(agate_table, options={}) %}
   {% set columns_start_index = 2 %}
   {% set columns_info = [] %}
   {% for col_name in agate_table.column_names %}
@@ -47,10 +47,14 @@
   {% endfor %}
   {{ dbt_unit_testing.println("| " ~ cells | join(" | ") ~ " |")}}
 
+  {% set last_spaces_replace_char = options.last_spaces_replace_char | default(" ") %}
   {% for row in agate_table.rows %}
     {% set cells = [] %}
     {% for cell_value in row %}
       {% set col_index = loop.index0 %}
+      {% if cell_value is string %}
+        {% set cell_value = dbt_unit_testing.replace_last_spaces_with(last_spaces_replace_char, cell_value) %}
+      {% endif %}
       {% set padded = dbt_unit_testing.pad(cell_value, columns_info[col_index].max_length, pad_right=cell_value is string) %}
       {% if columns_info[col_index].has_differences %}
         {% do cells.append("{RED}" ~ padded ~ "{RESET}") %}
@@ -60,7 +64,20 @@
     {% endfor %}
     {{ dbt_unit_testing.println("| " ~ cells | join(" | ") ~ " |")}}
   {% endfor %}
+{% endmacro %}
 
+{% macro replace_last_spaces_with(replacement, s) %}
+  {% set rs = s | reverse %}
+  {% set replaced = namespace(value="", stop=false) %}
+  {% for i in range(0, rs | length) %}
+    {% if rs[i] == ' ' and not replaced.stop %}
+      {% set replaced.value = replaced.value ~ replacement %}
+    {% else %}
+      {% set replaced.value = replaced.value ~ rs[i] %}
+      {% set replaced.stop = true %}
+    {% endif %}
+  {% endfor %}
+  {{ return(replaced.value | reverse) }}
 {% endmacro %}
 
 {% macro pad(v, pad, pad_right=false, c=" ") %}
@@ -77,6 +94,7 @@
       .replace("{RED}", "\x1b[0m\x1b[31m")
       .replace("{GREEN}", "\x1b[0m\x1b[32m")
       .replace("{YELLOW}", "\x1b[0m\x1b[33m")
+      .replace("{BG_YELLOW}", "\x1b[0m\x1b[43m")
       .replace("{RESET}", "\x1b[0m")) }}
 {% endmacro %}
 

macros/tests.sql

@@ -147,7 +147,7 @@
   {% endif %}
   {% if test_report.different_rows_count > 0 %}
     {{ dbt_unit_testing.println('{RED}ERROR: {YELLOW}Rows mismatch:') }}
-    {{ dbt_unit_testing.print_table(test_report.test_differences) }}
+    {{ dbt_unit_testing.print_table(test_report.test_differences, options=test_configuration.options) }}
   {% endif %}
 {% endmacro %}