Adding in NoMissingUnitTest linter rule

sqlmesh/core/context.py

@@ -115,6 +115,7 @@
     ModelTestMetadata,
     generate_test,
     run_tests,
+    filter_tests_by_patterns,
 )
 from sqlmesh.core.user import User
 from sqlmesh.utils import UniqueKeyDict, Verbosity
@@ -146,8 +147,8 @@
     from typing_extensions import Literal
 
     from sqlmesh.core.engine_adapter._typing import (
-        BigframeSession,
         DF,
+        BigframeSession,
         PySparkDataFrame,
         PySparkSession,
         SnowparkSession,
@@ -390,6 +391,8 @@ def __init__(
         self._standalone_audits: UniqueKeyDict[str, StandaloneAudit] = UniqueKeyDict(
             "standaloneaudits"
         )
+        self._models_with_tests: t.Set[str] = set()
+        self._model_test_metadata: t.List[ModelTestMetadata] = []
         self._macros: UniqueKeyDict[str, ExecutableOrMacro] = UniqueKeyDict("macros")
         self._metrics: UniqueKeyDict[str, Metric] = UniqueKeyDict("metrics")
         self._jinja_macros = JinjaMacroRegistry()
@@ -639,6 +642,8 @@ def load(self, update_schemas: bool = True) -> GenericContext[C]:
             self._requirements.update(project.requirements)
             self._excluded_requirements.update(project.excluded_requirements)
             self._environment_statements.extend(project.environment_statements)
+            self._models_with_tests.update(project.models_with_tests)
+            self._model_test_metadata.extend(project.model_test_metadata)
 
             config = loader.config
             self._linters[config.project] = Linter.from_rules(
@@ -1041,6 +1046,11 @@ def standalone_audits(self) -> MappingProxyType[str, StandaloneAudit]:
         """Returns all registered standalone audits in this context."""
         return MappingProxyType(self._standalone_audits)
 
+    @property
+    def models_with_tests(self) -> t.Set[str]:
+        """Returns all models with tests in this context."""
+        return self._models_with_tests
+
     @property
     def snapshots(self) -> t.Dict[str, Snapshot]:
         """Generates and returns snapshots based on models registered in this context.
@@ -2212,7 +2222,9 @@ def test(
 
             pd.set_option("display.max_columns", None)
 
-        test_meta = self.load_model_tests(tests=tests, patterns=match_patterns)
+        test_meta = self._filter_preloaded_tests(
+            test_meta=self._model_test_metadata, tests=tests, patterns=match_patterns
+        )
 
         result = run_tests(
             model_test_metadata=test_meta,
@@ -2773,6 +2785,35 @@ def _get_engine_adapter(self, gateway: t.Optional[str] = None) -> EngineAdapter:
             raise SQLMeshError(f"Gateway '{gateway}' not found in the available engine adapters.")
         return self.engine_adapter
 
+    def _filter_preloaded_tests(
+        self,
+        test_meta: t.List[ModelTestMetadata],
+        tests: t.Optional[t.List[str]] = None,
+        patterns: t.Optional[t.List[str]] = None,
+    ) -> t.List[ModelTestMetadata]:
+        """Filter pre-loaded test metadata based on tests and patterns."""
+
+        if tests:
+            filtered_tests = []
+            for test in tests:
+                if "::" in test:
+                    filename, test_name = test.split("::", maxsplit=1)
+                    filtered_tests.extend(
+                        [
+                            t
+                            for t in test_meta
+                            if str(t.path) == filename and t.test_name == test_name
+                        ]
+                    )
+                else:
+                    filtered_tests.extend([t for t in test_meta if str(t.path) == test])
+            test_meta = filtered_tests
+
+        if patterns:
+            test_meta = filter_tests_by_patterns(test_meta, patterns)
+
+        return test_meta
+
     def _snapshots(
         self, models_override: t.Optional[UniqueKeyDict[str, Model]] = None
     ) -> t.Dict[str, Snapshot]:

sqlmesh/core/linter/rules/builtin.py

@@ -129,6 +129,21 @@ def check_model(self, model: Model) -> t.Optional[RuleViolation]:
             return self.violation()
 
 
+class NoMissingUnitTest(Rule):
+    """All models must have a unit test found in the test/ directory yaml files"""
+
+    def check_model(self, model: Model) -> t.Optional[RuleViolation]:
+        #  External models cannot have unit tests
+        if isinstance(model, ExternalModel):
+            return None
+
+        if model.name not in self.context.models_with_tests:
+            return self.violation(
+                violation_msg=f"Model {model.name} is missing unit test(s). Please add in the tests/ directory."
+            )
+        return None
+
+
 class NoMissingExternalModels(Rule):
     """All external models must be registered in the external_models.yaml file"""
 

sqlmesh/core/loader.py

@@ -64,6 +64,8 @@ class LoadedProject:
     excluded_requirements: t.Set[str]
     environment_statements: t.List[EnvironmentStatements]
     user_rules: RuleSet
+    model_test_metadata: t.List[ModelTestMetadata]
+    models_with_tests: t.Set[str]
 
 
 class CacheBase(abc.ABC):
@@ -243,6 +245,12 @@ def load(self) -> LoadedProject:
 
             user_rules = self._load_linting_rules()
 
+            model_test_metadata = self.load_model_tests()
+
+            models_with_tests = {
+                model_test_metadata.model_name for model_test_metadata in model_test_metadata
+            }
+
             project = LoadedProject(
                 macros=macros,
                 jinja_macros=jinja_macros,
@@ -254,6 +262,8 @@ def load(self) -> LoadedProject:
                 excluded_requirements=excluded_requirements,
                 environment_statements=environment_statements,
                 user_rules=user_rules,
+                model_test_metadata=model_test_metadata,
+                models_with_tests=models_with_tests,
             )
             return project
 

sqlmesh/core/test/discovery.py

@@ -20,6 +20,10 @@ class ModelTestMetadata(PydanticModel):
     def fully_qualified_test_name(self) -> str:
         return f"{self.path}::{self.test_name}"
 
+    @property
+    def model_name(self) -> str:
+        return self.body["model"]
+
     def __hash__(self) -> int:
         return self.fully_qualified_test_name.__hash__()
 

tests/core/linter/test_builtin.py

@@ -172,3 +172,63 @@ def test_no_missing_external_models_with_existing_file_not_ending_in_newline(
     )
     fix_path = sushi_path / "external_models.yaml"
     assert edit.path == fix_path
+
+
+def test_no_missing_unit_tests(tmp_path, copy_to_temp_path):
+    """
+    Tests that the NoMissingUnitTest linter rule correctly identifies models
+    without corresponding unit tests in the tests/ directory
+
+    This test checks the sushi example project, enables the linter,
+    and verifies that the linter raises a rule violation for the models
+    that do not have a unit test
+    """
+    sushi_paths = copy_to_temp_path("examples/sushi")
+    sushi_path = sushi_paths[0]
+
+    # Override the config.py to turn on lint
+    with open(sushi_path / "config.py", "r") as f:
+        read_file = f.read()
+
+    before = """    linter=LinterConfig(
+        enabled=False,
+        rules=[
+            "ambiguousorinvalidcolumn",
+            "invalidselectstarexpansion",
+            "noselectstar",
+            "nomissingaudits",
+            "nomissingowner",
+            "nomissingexternalmodels",
+        ],
+    ),"""
+    after = """linter=LinterConfig(enabled=True, rules=["nomissingunittest"]),"""
+    read_file = read_file.replace(before, after)
+    assert after in read_file
+    with open(sushi_path / "config.py", "w") as f:
+        f.writelines(read_file)
+
+    # Load the context with the temporary sushi path
+    context = Context(paths=[sushi_path])
+
+    # Lint the models
+    lints = context.lint_models(raise_on_error=False)
+
+    # Should have violations for models without tests (most models except customers)
+    assert len(lints) >= 1
+
+    # Check that we get violations for models without tests
+    violation_messages = [lint.violation_msg for lint in lints]
+    assert any("is missing unit test(s)" in msg for msg in violation_messages)
+
+    # Check that models with existing tests don't have violations
+    models_with_tests = ["customer_revenue_by_day", "customer_revenue_lifetime", "order_items"]
+
+    for model_name in models_with_tests:
+        model_violations = [
+            lint
+            for lint in lints
+            if model_name in lint.violation_msg and "is missing unit test(s)" in lint.violation_msg
+        ]
+        assert len(model_violations) == 0, (
+            f"Model {model_name} should not have a violation since it has a test"
+        )