improve test

.changes/unreleased/Features-20251215-174308.yaml

@@ -0,0 +1,6 @@
+kind: Features
+body: Support --empty flag for dbt seed
+time: 2025-12-15T17:43:08.807815-05:00
+custom:
+    Author: michelleark
+    Issue: "8981"

.changes/unreleased/Under the Hood-20251215-155046.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: Bump lower bound for dbt-common to 1.37.2
+time: 2025-12-15T15:50:46.857793-05:00
+custom:
+    Author: michelleark
+    Issue: "12284"

core/dbt/cli/main.py

@@ -691,6 +691,7 @@ def run_operation(ctx, **kwargs):
 @cli.command("seed")
 @click.pass_context
 @global_flags
+@p.empty
 @p.exclude
 @p.full_refresh
 @p.profiles_dir

core/dbt/constants.py

@@ -6,6 +6,9 @@ SECRET_PLACEHOLDER = "$$$DBT_SECRET_START$$${}$$$DBT_SECRET_END$$$"
 
 MAXIMUM_SEED_SIZE = 1 * 1024 * 1024
 MAXIMUM_SEED_SIZE_NAME = "1MB"
+# Number of rows to load as agate table to obtain column types for empty seed table creation
+# Seed materializations themselves avoid loading the data to the warehouse
+EMPTY_SEED_SIZE = 5
 
 PIN_PACKAGE_URL = (
     "https://docs.getdbt.com/docs/package-management#section-specifying-package-versions"

core/dbt/context/providers.py

@@ -43,7 +43,7 @@ from dbt.clients.jinja import (
 )
 from dbt.clients.jinja_static import statically_parse_unrendered_config
 from dbt.config import IsFQNResource, Project, RuntimeConfig
-from dbt.constants import DEFAULT_ENV_PLACEHOLDER
+from dbt.constants import DEFAULT_ENV_PLACEHOLDER, EMPTY_SEED_SIZE
 from dbt.context.base import Var, contextmember, contextproperty
 from dbt.context.configured import FQNLookup
 from dbt.context.context_config import ContextConfig
@@ -1269,6 +1269,8 @@ class ProviderContext(ManifestContext):
         delimiter = self.model.config.delimiter
         try:
             table = agate_helper.from_csv(path, text_columns=column_types, delimiter=delimiter)
+            if getattr(self.config.args, "EMPTY", False):
+                table = table.limit(EMPTY_SEED_SIZE)  # type: ignore
         except ValueError as e:
             raise LoadAgateTableValueError(e, node=self.model)
         # this is used by some adapters

core/pyproject.toml

@@ -54,7 +54,7 @@ dependencies = [
     "dbt-extractor>=0.5.0,<=0.6",
     "dbt-semantic-interfaces>=0.9.0,<0.10",
     # Minor versions for these are expected to be backwards-compatible
-    "dbt-common>=1.37.0,<2.0",
+    "dbt-common>=1.37.2,<2.0",
     "dbt-adapters>=1.15.5,<2.0",
     "dbt-protos>=1.0.405,<2.0",
     "pydantic<3",

tests/functional/configs/test_get_default.py

@@ -33,7 +33,7 @@ select {{ config.require('meta_key') }} as col_value
 
 meta_model_meta_require_sql = """
 -- models/meta_model.sql
-select {{ config.require('meta_key') }} as col_value
+select {{ config.meta_require('meta_key') }} as col_value
 """
 
 
@@ -66,11 +66,11 @@ class TestConfigGetMeta:
         self,
         project,
     ):
-        # This test runs a model with a config.get(key, default)
+        # This test runs a model with a config.get(key, default) -> default value returned
         results = run_dbt(["run"], expect_pass=False)
         assert len(results) == 1
         assert str(results[0].status) == "error"
-        assert 'column "my_meta_value" does not exist' in results[0].message
+        assert 'column "meta_default_value" does not exist' in results[0].message
 
         write_file(meta_model_meta_get_sql, "models", "meta_model.sql")
         results = run_dbt(["run"], expect_pass=False)
@@ -95,10 +95,10 @@ class TestConfigGetMetaRequire:
         results = run_dbt(["run"], expect_pass=False)
         assert len(results) == 1
         assert str(results[0].status) == "error"
-        assert 'column "my_meta_value" does not exist' in results[0].message
+        assert "does not define a required config parameter 'meta_key'" in results[0].message
 
         write_file(meta_model_meta_require_sql, "models", "meta_model.sql")
         results = run_dbt(["run"], expect_pass=False)
         assert len(results) == 1
         assert str(results[0].status) == "error"
-        assert 'column "my_meta_value" does not exist' in results[0].message
+        assert 'column "none" does not exist' in results[0].message

tests/functional/test_empty.py

@@ -15,6 +15,10 @@ raw_source_csv = """id
 3
 """
 
+raw_seed_csv = """a,b,c,d,e,f
+3.2,3,US,2025-01-01,none,false
+4.5,4,UK,2025-01-02,2,true
+"""
 
 model_sql = """
 select *
@@ -67,8 +71,29 @@ unit_tests:
         2
 """
 
+unit_tests_seed_yml = """
+unit_tests:
+  - name: test_my_seed
+    model: model
+    given:
+      - input: ref('raw_seed')
+    expect:
+      format: csv
+      rows: |
+        a,b,c,d,e,f
+        3.2,3,US,2025-01-01,none,false
+        4.5,4,UK,2025-01-02,2,true
+"""
 
-class TestEmptyFlag:
+
+class BaseTestEmptyFlag:
+    def assert_row_count(self, project, relation_name: str, expected_row_count: int):
+        relation = relation_from_name(project.adapter, relation_name)
+        result = project.run_sql(f"select count(*) as num_rows from {relation}", fetch="one")
+        assert result[0] == expected_row_count
+
+
+class TestEmptyFlag(BaseTestEmptyFlag):
     @pytest.fixture(scope="class")
     def seeds(self):
         return {
@@ -86,14 +111,10 @@ class TestEmptyFlag:
             "unit_tests.yml": unit_tests_yml,
         }
 
-    def assert_row_count(self, project, relation_name: str, expected_row_count: int):
-        relation = relation_from_name(project.adapter, relation_name)
-        result = project.run_sql(f"select count(*) as num_rows from {relation}", fetch="one")
-        assert result[0] == expected_row_count
-
     def test_run_with_empty(self, project):
-        # create source from seed
+        # Create source from seed for run and build command testing
         run_dbt(["seed"])
+        self.assert_row_count(project, "raw_source", 1)
 
         # run without empty - 3 expected rows in output - 1 from each input
         run_dbt(["run"])
@@ -113,3 +134,27 @@ class TestEmptyFlag:
 
         # ensure dbt compile supports --empty flag
         run_dbt(["compile", "--empty"])
+
+
+class TestEmptyFlagSeed(BaseTestEmptyFlag):
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {
+            "raw_seed.csv": raw_seed_csv,
+        }
+
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "model.sql": "select * from {{ ref('raw_seed') }}",
+            "unit_tests.yml": unit_tests_seed_yml,
+        }
+
+    def test_run_with_empty(self, project):
+        run_dbt(["seed", "--empty"])
+        self.assert_row_count(project, "raw_seed", 0)
+
+        results = run_dbt(["build", "--empty"])
+        self.assert_row_count(project, "raw_seed", 0)
+
+        assert len(results) == 3