feat: add DataSource.reset() API

When writing tests, for performance reasons we often want to reuse the same data-source instance for many tests suites. At the same time, we want to keep such test suites independent and allow them to reuse the same model name for different model classes. Juggler does support redefinition of a model with the same name. This change is adding a new API called `dataSource.reset()` that allows tests to remove all old models before creating new ones (typically from a `before` hook). Signed-off-by: Miroslav Bajtoš <[email protected]>
loopbackio · Jul 18, 2019 · fde6d6a · fde6d6a
1 parent 6aea50a
commit fde6d6a
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diff --git a/lib/datasource.js b/lib/datasource.js
@@ -844,6 +844,16 @@ DataSource.prototype.deleteModelByName = function(modelName) {
   delete this.connector._models[modelName];
 };
 
+/**
+ * Remove all models from the registry, but keep the connector instance
+ * (including the pool of database connections).
+ */
+DataSource.prototype.reset = function() {
+  for (const m in this.modelBuilder.models) {
+    this.deleteModelByName(m);
+  }
+};
+
 /**
  * Mixin DataAccessObject methods.
  *

diff --git a/test/datasource.test.js b/test/datasource.test.js
@@ -517,6 +517,34 @@ describe('DataSource', function() {
       });
     }
   });
+
+  describe('reset', () => {
+    it('removes all model definitions', () => {
+      const ds = new DataSource({connector: 'memory'});
+      ds.define('Category');
+      ds.define('Product');
+
+      Object.keys(ds.modelBuilder.definitions)
+        .should.deepEqual(['Category', 'Product']);
+      Object.keys(ds.modelBuilder.models)
+        .should.deepEqual(['Category', 'Product']);
+      Object.keys(ds.connector._models)
+        .should.deepEqual(['Category', 'Product']);
+
+      ds.reset();
+
+      Object.keys(ds.modelBuilder.definitions).should.be.empty();
+      Object.keys(ds.modelBuilder.models).should.be.empty();
+      Object.keys(ds.connector._models).should.be.empty();
+    });
+
+    it('preserves the connector instance', () => {
+      const ds = new DataSource({connector: 'memory'});
+      const connector = ds.connector;
+      ds.reset();
+      ds.connector.should.equal(connector);
+    });
+  });
 });
 
 function givenMockConnector(props) {