From 6197f8d9d52f5b19d45ba13a893d879d4068d818 Mon Sep 17 00:00:00 2001
From: Patrick Silva <patricksmms@users.noreply.github.com>
Date: Tue, 8 Sep 2020 13:13:58 +0200
Subject: [PATCH] fix(core): prefer sample/default over undefined props (#556)

Prefer sample/default over Object with undefined property values
---
 packages/api-elements/CHANGELOG.md           |  7 +++++
 packages/api-elements/lib/define-value-of.js |  8 ++++--
 packages/api-elements/package.json           |  2 +-
 packages/api-elements/test/value-of-test.js  | 28 ++++++++++++++++++++
 4 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/packages/api-elements/CHANGELOG.md b/packages/api-elements/CHANGELOG.md
index 45b6eee00..42ead9e4b 100644
--- a/packages/api-elements/CHANGELOG.md
+++ b/packages/api-elements/CHANGELOG.md
@@ -1,5 +1,12 @@
 # API Elements (JavaScript) CHANGELOG
 
+## 0.3.1 (2020-09-07)
+
+### Bug Fixes
+
+- Generating a value from an element will now prefer sample/default values for
+  objects which contain only undefined property values.
+
 ## 0.3.0 (2020-08-05)
 
 ### Bug Fixes
diff --git a/packages/api-elements/lib/define-value-of.js b/packages/api-elements/lib/define-value-of.js
index 01add0808..f7866c00b 100644
--- a/packages/api-elements/lib/define-value-of.js
+++ b/packages/api-elements/lib/define-value-of.js
@@ -86,6 +86,7 @@ function findFirstSample(e) {
 const isPrimitive = e => (e instanceof StringElement) || (e instanceof NumberElement) || (e instanceof BooleanElement);
 const isEnumElement = e => e instanceof EnumElement;
 const isArrayElement = e => e instanceof ArrayElement;
+const isObjectElement = e => e instanceof ObjectElement;
 
 const hasSample = e => findFirstSample(e) !== null;
 const hasDefault = e => findDefault(e) !== null;
@@ -94,6 +95,9 @@ const hasValue = R.anyPass([hasContent, hasSample, hasDefault]);
 const hasNoValue = R.complement(hasValue);
 const isNoValuePrimitive = R.both(isPrimitive, hasNoValue);
 const isNonEmptyArrayElement = e => isArrayElement(e) && e.content && !e.isEmpty;
+const isEmptyArray = e => isArrayElement(e) && e.content.every(isNoValuePrimitive);
+const isObjectWithUndefinedValues = e => isObjectElement(e)
+  && e.content.every(prop => prop.value === undefined || prop.value.content === undefined);
 
 
 function trivialValue(e) {
@@ -123,7 +127,7 @@ function mapValue(e, options, f, elements) {
 
   const opts = updateTypeAttributes(e, options);
 
-  if (e.content && !(isArrayElement(e) && e.content.every(isNoValuePrimitive))) {
+  if (e.content && !isEmptyArray(e) && !isObjectWithUndefinedValues(e)) {
     const result = f(e, opts, elements, 'content');
 
     if (undefined !== result) {
@@ -226,7 +230,7 @@ function reduceValue(e, options, elements) {
     return mapValue(e.content, inheritFlags(opts), reduceValue, elements);
   }
 
-  if (e instanceof ObjectElement) {
+  if (isObjectElement(e)) {
     let result = {};
 
     const isFixed = isFlag(FIXED_FLAG, opts);
diff --git a/packages/api-elements/package.json b/packages/api-elements/package.json
index 61b894809..b4998ec33 100644
--- a/packages/api-elements/package.json
+++ b/packages/api-elements/package.json
@@ -1,6 +1,6 @@
 {
   "name": "api-elements",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "API Elements JavaScript",
   "author": "Apiary.io <support@apiary.io>",
   "license": "MIT",
diff --git a/packages/api-elements/test/value-of-test.js b/packages/api-elements/test/value-of-test.js
index 621de08a2..502b40efb 100644
--- a/packages/api-elements/test/value-of-test.js
+++ b/packages/api-elements/test/value-of-test.js
@@ -968,6 +968,34 @@ describe('valueOf ObjectElement', () => {
     expect(value).to.deep.equal({ gaga: 'bing' });
   });
 
+  it('prefers samples over undefined property values', () => {
+    const element = new ObjectElement({ key1: new StringElement(), key2: new StringElement() });
+    element.attributes.set('default', new ObjectElement({ key1: 'defaultValue', key2: 'otherDefaultValue' }));
+    element.attributes.set('samples', new ArrayElement([
+      new ObjectElement({ key1: 'sampleValue', key2: 'otherSampleValue' }),
+    ]));
+    const value = element.valueOf();
+
+    expect(value).to.deep.equal({ key1: 'sampleValue', key2: 'otherSampleValue' });
+  });
+
+  it.only('prefers default over undefined property values', () => {
+    const defaults = new ObjectElement({ key1: 'defaultValue', key2: 'otherDefaultValue' });
+
+    const element1 = new ObjectElement({ key1: new StringElement(), key2: new StringElement() });
+    element1.attributes.set('default', defaults);
+    const value1 = element1.valueOf();
+
+    const element2 = new ObjectElement([
+      new MemberElement(), new MemberElement(),
+    ]);
+    element2.attributes.set('default', defaults);
+    const value2 = element2.valueOf();
+
+    expect(value1).to.deep.equal({ key1: 'defaultValue', key2: 'otherDefaultValue' });
+    expect(value2).to.deep.equal({ key1: 'defaultValue', key2: 'otherDefaultValue' });
+  });
+
   it('generates {} if no content, default, samples and not nullable', () => {
     const element = new ObjectElement();
     const value = element.valueOf();