Merge pull request #412 from strongloop/feature/before-delete-hook

Implement intent hook `before delete`

lib/dao.js

@@ -995,7 +995,11 @@ DataAccessObject.remove = DataAccessObject.deleteAll = DataAccessObject.destroyA
       { Model: Model, query: query },
       function(err, ctx) {
         if (err) return cb(err);
-        doDelete(ctx.query.where);
+        var context = { Model: Model, where: ctx.query.where };
+        Model.notifyObserversOf('before delete', context, function(err, ctx) {
+          if (err) return cb(err);
+          doDelete(ctx.where);
+        });
       });
   }
 
@@ -1311,7 +1315,13 @@ DataAccessObject.prototype.remove =
         { Model: Model, query: byIdQuery(Model, id) },
         function(err, ctx) {
           if (err) return cb(err);
-          doDeleteInstance(ctx.query.where);
+          Model.notifyObserversOf(
+            'before delete',
+            { Model: Model, where: ctx.query.where },
+            function(err, ctx) {
+              if (err) return cb(err);
+              doDeleteInstance(ctx.where);
+            });
         });
 
       function doDeleteInstance(where) {

test/persistence-hooks.suite.js

@@ -893,6 +893,57 @@ module.exports = function(dataSource, should) {
         });
       });
 
+      it('triggers `before delete` hook with query', function(done) {
+        TestModel.observe('before delete', pushContextAndNext());
+
+        TestModel.deleteAll({ name: existingInstance.name }, function(err) {
+          if (err) return done(err);
+          observedContexts.should.eql(aTestModelCtx({
+             where: { name: existingInstance.name }
+          }));
+          done();
+        });
+      });
+
+      it('triggers `before delete` hook without query', function(done) {
+        TestModel.observe('before delete', pushContextAndNext());
+
+        TestModel.deleteAll(function(err) {
+          if (err) return done(err);
+          observedContexts.should.eql(aTestModelCtx({ where: {} }));
+          done();
+        });
+      });
+
+      it('applies updates from `before delete` hook', function(done) {
+        TestModel.observe('before delete', function(ctx, next) {
+          ctx.where = { id: { neq: existingInstance.id } };
+          next();
+        });
+
+        TestModel.deleteAll(function(err) {
+          if (err) return done(err);
+          findTestModels(function(err, list) {
+            if (err) return done(err);
+            (list || []).map(get('id')).should.eql([existingInstance.id]);
+            done();
+          });
+        });
+      });
+
+      it('aborts when `before delete` hook fails', function(done) {
+        TestModel.observe('before delete', nextWithError(expectedError));
+
+        TestModel.deleteAll(function(err, list) {
+          [err].should.eql([expectedError]);
+          TestModel.findById(existingInstance.id, function(err, inst) {
+            if (err) return done(err);
+            (inst ? inst.toObject() : 'null').should.eql(existingInstance.toObject());
+            done();
+          });
+        });
+      });
+
       it('triggers `after delete` hook without query', function(done) {
         TestModel.observe('after delete', pushContextAndNext());
 
@@ -954,6 +1005,47 @@ module.exports = function(dataSource, should) {
         });
       });
 
+      it('triggers `before delete` hook', function(done) {
+        TestModel.observe('before delete', pushContextAndNext());
+
+        existingInstance.delete(function(err) {
+          if (err) return done(err);
+          observedContexts.should.eql(aTestModelCtx({
+             where: { id: existingInstance.id }
+          }));
+          done();
+        });
+      });
+
+      it('applies updated from `before delete` hook', function(done) {
+        TestModel.observe('before delete', function(ctx, next) {
+          ctx.where = { id: { neq: existingInstance.id } };
+          next();
+        });
+
+        existingInstance.delete(function(err) {
+          if (err) return done(err);
+          findTestModels(function(err, list) {
+            if (err) return done(err);
+            (list || []).map(get('id')).should.eql([existingInstance.id]);
+            done();
+          });
+        });
+      });
+
+      it('aborts when `before delete` hook fails', function(done) {
+        TestModel.observe('before delete', nextWithError(expectedError));
+
+        existingInstance.delete(function(err, list) {
+          [err].should.eql([expectedError]);
+          TestModel.findById(existingInstance.id, function(err, inst) {
+            if (err) return done(err);
+            (inst ? inst.toObject() : 'null').should.eql(existingInstance.toObject());
+            done();
+          });
+        });
+      });
+
       it('triggers `after delete` hook', function(done) {
         TestModel.observe('after delete', pushContextAndNext());