addressing brendan's review for ALL the brownie points.

Author: paulirish

lighthouse-core/audits/manifest-background-color.js

@@ -39,7 +39,6 @@ class ManifestBackgroundColor extends Audit {
    */
   static getBackgroundColorValue(manifest) {
     return manifest !== undefined &&
-      manifest.background_color !== undefined &&
       manifest.background_color.value;
   }
 
@@ -53,9 +52,7 @@ class ManifestBackgroundColor extends Audit {
     return ManifestBackgroundColor.generateAuditResult({
       rawValue: !!bgColor,
       extendedInfo: {
-        value: {
-          color: bgColor
-        },
+        value: bgColor,
         formatter: Formatter.SUPPORTED_FORMATS.NULL
       }
     });

lighthouse-core/test/audits/background-color.js

@@ -67,7 +67,7 @@ describe('Manifest: background color audit', () => {
     };
     const output = Audit.audit(artifacts);
     assert.equal(output.rawValue, true);
-    assert.equal(output.extendedInfo.value.color, '#FAFAFA');
+    assert.equal(output.extendedInfo.value, '#FAFAFA');
   });
 
   it('succeeds when a complete manifest contains a background_color', () => {

lighthouse-core/test/audits/cache-start-url.js

@@ -45,15 +45,6 @@ describe('Cache: start_url audit', () => {
 
   // Need to disable camelcase check for dealing with start_url.
   /* eslint-disable camelcase */
-  it('fails when a manifest artifact contains no start_url', () => {
-    const artifacts = {
-      Manifest: { }
-    };
-    const output = Audit.audit(artifacts);
-    assert.equal(output.rawValue, false);
-    assert.equal(output.debugString, 'start_url not present in Manifest');
-  });
-
   it('fails when a manifest contains no start_url', () => {
     const artifacts = {
       Manifest: manifestParser('{}')

lighthouse-core/test/audits/display.js

@@ -38,7 +38,7 @@ describe('Mobile-friendly: display audit', () => {
 
   it('handles the case where there is no manifest display property', () => {
     const artifacts = {
-      Manifest: manifestParser({})
+      Manifest: manifestParser('{}')
     };
     const output = Audit.audit(artifacts);
 

lighthouse-core/test/audits/exists.js

@@ -29,12 +29,6 @@ describe('Manifest: exists audit', () => {
     }}).rawValue, false);
   });
 
-  it('succeeds when a manifest artifact is present', () => {
-    return assert.equal(Audit.audit({Manifest: {
-      value: {}
-    }}).rawValue, true);
-  });
-
   it('succeeds with a valid minimal manifest', () => {
     const artifacts = {
       Manifest: manifestParser('{}')

lighthouse-core/test/audits/start-url.js

@@ -37,7 +37,7 @@ describe('Manifest: start_url audit', () => {
     assert.equal(output.debugString, undefined);
   });
 
-  // Need to disable camelcase check for dealing with short_name.
+  // Need to disable camelcase check for dealing with start_url.
   /* eslint-disable camelcase */
   it('fails when a manifest contains no start_url', () => {
     const artifacts = {