Remove ununsed models from model config (#94)

Author: scottypate

build/ci/integration-test.sh

@@ -25,7 +25,3 @@ if [[ $MONGO_RESULTS_LENGTH -ne 1 ]]; then
   echo "Expected 1 row in mongodb_test, got $MONGO_RESULTS_LENGTH"
   exit 1
 fi
-
-
-echo "Information schema results from test suite:"
-echo $(bin/preen query -f json"select * from preen_information_schema;")

build/ci/models.yaml

@@ -34,4 +34,4 @@ models:
         test_data_types.mysql_field_set,
         test_data_types.mysql_field_json
       from
-        test_data_types;
+        test_data_types;

build/ci/models/unused.yml

@@ -0,0 +1,7 @@
+name: unused
+type: database
+query: |
+  select
+    test_data_types.not_used
+  from
+    test_data_types;

internal/engine/config.go

@@ -23,6 +23,10 @@ func ValidateConfigs(sc *SourceConfig, mc *ModelConfig) error {
 		return fmt.Errorf("error on missing models: %w", err)
 	}
 
+	if err := removeUnusedModels(sc, mc); err != nil {
+		return fmt.Errorf("error removing unused models: %w", err)
+	}
+
 	if err := parseModels(mc); err != nil {
 		return fmt.Errorf("error parsing models: %w", err)
 	}

internal/engine/models.go

@@ -125,6 +125,10 @@ func BuildModels(sc *SourceConfig, mc *ModelConfig) error {
 		return fmt.Errorf("error building information schema: %w", err)
 	}
 
+	if err := removeUnusedModels(sc, mc); err != nil {
+		return fmt.Errorf("error removing unused models: %w", err)
+	}
+
 	columnMetadata, err := BuildColumnMetadata()
 	if err != nil {
 		return fmt.Errorf("error building column metadata: %w", err)
@@ -277,3 +281,22 @@ func errorOnMissingModels(sc *SourceConfig, mc *ModelConfig) error {
 	}
 	return nil
 }
+
+// Remove unused models from ModelConfig. If a model is not referenced in any source, it is unused.
+func removeUnusedModels(sc *SourceConfig, mc *ModelConfig) error {
+	usedModels := make([]string, 0)
+	for _, source := range sc.Sources {
+		for _, modelName := range source.Models {
+			usedModels = append(usedModels, string(modelName))
+		}
+	}
+
+	for i, model := range mc.Models {
+		if !slices.Contains(usedModels, string(model.Name)) {
+			Info(fmt.Sprintf("Removing unused model: %s", model.Name))
+			mc.Models = append(mc.Models[:i], mc.Models[i+1:]...)
+		}
+	}
+
+	return nil
+}