bbc · llouisetaylor · Dec 20, 2019 · Nov 22, 2019 · Nov 22, 2019 · Nov 22, 2019
diff --git a/features/hiding_errors.feature b/features/hiding_errors.feature
@@ -1,7 +1,7 @@
 Feature: Hiding errors
 
-  Things like ORB and Barlesque that we don't control will clutter up our pages
-  with violations.
+  Websites often contain external parts that we don't control, which will 
+  clutter up our pages with violations.
 
   We need a way to ignore these kinds of problems, so we can focus on the
   problems that we can actually fix.

diff --git a/features/hiding_warnings.feature b/features/hiding_warnings.feature
@@ -0,0 +1,39 @@
+Feature: Hiding warnings
+
+  Websites often contain external parts that we don't control, which will 
+  clutter up our pages with violations.
+
+  We need a way to ignore these kinds of problems, so we can focus on the
+  problems that we can actually fix.
+
+  Scenario: Hide warnings matching a selector
+    Given a website running at http://localhost:54321
+    And a file named "a11y.js" with:
+      """
+      page("http://localhost:54321/one_warning.html", {
+        hide: "@id='main'"
+      })
+      """
+    When I run `bbc-a11y`
+    Then it should pass with:
+      """
+      ✓ http://localhost:54321/one_warning.html
+
+      1 page checked, 0 errors found, 0 warnings, 1 warning hidden, 0 standards skipped
+      """
+
+  Scenario: Hide warnings matching a rule
+    Given a website running at http://localhost:54321
+    And a file named "a11y.js" with:
+      """
+      page("http://localhost:54321/one_warning.html", {
+        hide: "First heading was not a main heading"
+      })
+      """
+    When I run `bbc-a11y`
+    Then it should pass with:
+      """
+      ✓ http://localhost:54321/one_warning.html
+
+      1 page checked, 0 errors found, 0 warnings, 1 warning hidden, 0 standards skipped
+      """
diff --git a/features/support/web_server/one_warning.html b/features/support/web_server/one_warning.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en-gb">
+  <head>
+    <title>Blank</title>
+  </head>
+  <body>
+    <div id="main" role="main">
+      <h2>h2</h2>
+      <h1>h1</h1>
+      <p>hello</p>
+    </div>
+  </body>
+</html>
diff --git a/lib/reporters/pretty.js b/lib/reporters/pretty.js
@@ -11,6 +11,7 @@ PrettyReporter.prototype.runStarted = function () {
     errorsFound: 0,
     errorsHidden: 0,
     warningsFound: 0,
+    warningsHidden: 0,
     standardsSkipped: 0,
     documentationUrls: []
   }
@@ -68,6 +69,7 @@ PrettyReporter.prototype.pageChecked = function (page, pageResult) {
   pageResult.results.forEach(function (standardResult) {
     summary.errorsHidden += standardResult.hiddenErrors.length
     summary.warningsFound += standardResult.warnings.length
+    summary.warningsHidden += standardResult.hiddenWarnings.length
   })
 
   var hasErrors = pageResult.results.some(r => r.errors.length > 0)
@@ -116,6 +118,7 @@ PrettyReporter.prototype.runEnded = function () {
     pluralise(this.summary.errorsFound, 'error') + ' found, ' +
     (this.summary.errorsHidden > 0 ? pluralise(this.summary.errorsHidden, 'error') + ' hidden, ' : '') +
     pluralise(this.summary.warningsFound, 'warning') + ', ' +
+    (this.summary.warningsHidden > 0 ? pluralise(this.summary.warningsHidden, 'warning') + ' hidden, ' : '') +
     pluralise(this.summary.standardsSkipped, 'standard') + ' skipped'
   )
   this.commandLineConsole.log('')

diff --git a/lib/results/standardResult.js b/lib/results/standardResult.js
@@ -5,6 +5,7 @@ function StandardResult (section, name, hide) {
   this.errors = []
   this.warnings = []
   this.hiddenErrors = []
+  this.hiddenWarnings = []
   this.hide = hide
 }
 
@@ -28,6 +29,20 @@ StandardResult.prototype.addError = function (errorChain) {
 
 StandardResult.prototype.addWarning = function (errorChain) {
   this.warnings.push(xpath.replaceElementsWithXPaths(errorChain))
+
+  if (this.hide) {
+    var standardResult = this
+    var hide = this.hide
+    standardResult.hiddenWarnings = standardResult.warnings.filter(function (warning) {
+      var fullWarningName = warning.map(function (e) { return e.xpath || e }).join(' ')
+      return (hide.find(function (substring) {
+        return fullWarningName.indexOf(substring) > -1
+      }))
+    })
+    standardResult.warnings = standardResult.warnings.filter(function (warning) {
+      return standardResult.hiddenWarnings.indexOf(warning) === -1
+    })
+  }
 }
 
 StandardResult.prototype.flatten = function () {

diff --git a/test/a11ySpec.js b/test/a11ySpec.js
@@ -40,6 +40,18 @@ describe('a11y', function () {
       })
   })
 
+  it('hides warnings', function () {
+    $('body').append('<h2>I am in the wrong place</h2><h1>Hello!</h1>')
+    return a11y.test({ hide: ['First heading was not a main heading'] })
+      .then(function (outcome) {
+        var resultsWithWarnings = outcome.results.filter(function (standardResult) {
+          return standardResult.hiddenWarnings.length > 0
+        })
+        expect(resultsWithWarnings[0].warnings).to.eql([])
+        expect(resultsWithWarnings[0].hiddenWarnings[0][0]).to.eql('First heading was not a main heading:')
+      })
+  })
+
   it('only runs specific standards', function () {
     return a11y.test({ only: ['Structure: Containers and landmarks: Exactly one main landmark'] })
       .then(function (outcome) {