From fd03302f08418654087e6a9e41f35e8286d8cb5d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Miroslav=20Bajto=C5=A1?= Date: Mon, 1 Apr 2019 13:18:05 +0200 Subject: [PATCH] Do not apply default values on data from database Before this change, when a property was configured with a default value at LoopBack side and the database was returned a record with a missing value for such property, then we would supply use the configured default. This behavior is problematic for reasons explained in #1692. In this commit, we are introducing a new model-level setting called `applyDefaultsOnReads`, which is enabled by default for backwards compatibility. When this setting is set to `false`, operations like `find` and `findOrCreate` will NOT apply default property values on data returned by the database (connector). Please note that most of the other CRUD methods did not apply default values on database data as long as the connector provided native implementation of the operation, that aspect is not changing. Also note that default values are applied only on properties with `undefined` values. The value `null` does not trigger application of default values. This is important because SQL connectors return `null` for properties with no value set. --- lib/dao.js | 14 ++++++-- test/basic-querying.test.js | 69 +++++++++++++++++++++++++++++++++++ test/manipulation.test.js | 72 +++++++++++++++++++++++++++++++++++++ 3 files changed, 153 insertions(+), 2 deletions(-) diff --git a/lib/dao.js b/lib/dao.js index cf7dc7ea..75bb0b09 100644 --- a/lib/dao.js +++ b/lib/dao.js @@ -1109,8 +1109,15 @@ DataAccessObject.findOrCreate = function findOrCreate(query, data, options, cb) let obj; if (data) { - obj = new Model(data, {fields: query.fields, applySetters: false, - persisted: true}); + const ctorOpts = { + fields: query.fields, + applySetters: false, + persisted: true, + }; + if (Model.settings.applyDefaultsOnReads === false) { + ctorOpts.applyDefaultValues = false; + } + obj = new Model(data, ctorOpts); } if (created) { @@ -1632,6 +1639,9 @@ DataAccessObject.find = function find(query, options, cb) { applySetters: false, persisted: true, }; + if (Model.settings.applyDefaultsOnReads === false) { + ctorOpts.applyDefaultValues = false; + } let obj; try { obj = new Model(data, ctorOpts); diff --git a/test/basic-querying.test.js b/test/basic-querying.test.js index 57fd3b4e..cef6f540 100644 --- a/test/basic-querying.test.js +++ b/test/basic-querying.test.js @@ -917,6 +917,75 @@ describe('basic-querying', function() { }); }); }); + + it('applies default values by default', () => { + // Backwards compatibility, see + // https://github.com/strongloop/loopback-datasource-juggler/issues/1692 + + // Initially, all Players were always active, no property was needed + const Player = db.define('Player', {name: String}); + let created; + return db.automigrate('Player') + .then(() => Player.create({name: 'Pen'})) + .then(result => { + created = result; + + // Later on, we decide to introduce `active` property + Player.defineProperty('active', { + type: Boolean, + default: false, + }); + return db.autoupdate('Player'); + }) + .then(() => { + // And query existing data + return Player.findOne(); + }) + .then(found => { + should(found.toObject().active).be.oneOf([ + // For databases supporting `undefined` value, + // we convert `undefined` to property default. + false, + // For databases representing `undefined` as `null` (e.g. SQL), + // we treat `null` as a defined value and don't apply defaults. + null, + ]); + }); + }); + + it('preserves empty values from the database when "applyDefaultsOnReads" is false', () => { + // https://github.com/strongloop/loopback-datasource-juggler/issues/1692 + + // Initially, all Players were always active, no property was needed + const Player = db.define( + 'Player', + {name: String}, + {applyDefaultsOnReads: false} + ); + let created; + return db.automigrate('Player') + .then(() => Player.create({name: 'Pen'})) + .then(result => { + created = result; + + // Later on, we decide to introduce `active` property + Player.defineProperty('active', { + type: Boolean, + default: false, + }); + return db.autoupdate('Player'); + }) + .then(() => { + // And query existing data + return Player.findOne(); + }) + .then(found => { + should(found.toObject().active).be.oneOf([ + undefined, // databases supporting `undefined` value + null, // databases representing `undefined` as `null` + ]); + }); + }); }); describe('count', function() { diff --git a/test/manipulation.test.js b/test/manipulation.test.js index 9c939c0d..7a42726d 100644 --- a/test/manipulation.test.js +++ b/test/manipulation.test.js @@ -1619,6 +1619,78 @@ describe('manipulation', function() { }) .catch(done); }); + + it('applies default values on returned data', () => { + // Backwards compatibility, see + // https://github.com/strongloop/loopback-datasource-juggler/issues/1692 + + // Initially, all Players were always active, no property was needed + const Player = db.define('Player', {name: String}); + let created; + return db.automigrate('Player') + .then(() => Player.create({name: 'Pen'})) + .then(result => { + created = result; + + // Later on, we decide to introduce `active` property + Player.defineProperty('active', { + type: Boolean, + default: false, + }); + return db.autoupdate('Player'); + }) + .then(() => { + // and findOrCreate an existing record + return Player.findOrCreate({id: created.id}, {name: 'updated'}); + }) + .spread(found => { + // Backwards-compatibility + // When Pen does not have "active" flag set, we change it to default + should(found.toObject().active).be.oneOf([ + // For databases supporting `undefined` value, + // we convert `undefined` to property default. + false, + // For databases representing `undefined` as `null` (e.g. SQL), + // we treat `null` as a defined value and don't apply defaults. + null, + ]); + }); + }); + + it('preserves empty values from the database when "applyDefaultsOnReads" is false', () => { + // https://github.com/strongloop/loopback-datasource-juggler/issues/1692 + + // Initially, all Players were always active, no property was needed + const Player = db.define( + 'Player', + {name: String}, + {applyDefaultsOnReads: false} + ); + let created; + + return db.automigrate('Player') + .then(() => Player.create({name: 'Pen'})) + .then(result => { + created = result; + + // Later on, we decide to introduce `active` property + Player.defineProperty('active', { + type: Boolean, + default: false, + }); + return db.autoupdate('Player'); + }) + .then(() => { + // And findOrCreate an existing record + return Player.findOrCreate({id: created.id}, {name: 'updated'}); + }) + .spread(found => { + should(found.toObject().active).be.oneOf([ + undefined, // databases supporting `undefined` value + null, // databases representing `undefined` as `null` + ]); + }); + }); }); describe('destroy', function() {