add dependencies, linter, test

Author: khiga8

.gitignore

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+*.gem
+*.rbc
+vendor
+Gemfile.lock

.rubocop.yml

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+inherit_gem:
+  rubocop-github:
+    - config/default_edge.yml
+    - config/rails_edge.yml
+
+AllCops:
+  NewCops: enable
+
+Rails/RefuteMethods:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false

Gemfile

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+# frozen_string_literal: true
+
+source "https://rubygems.org"
+gemspec

Rakefile

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+# frozen_string_literal: true
+
+require "bundler/gem_tasks"
+require "rake/testtask"
+
+Rake::TestTask.new do |t|
+  t.libs << "test"
+end
+
+desc "Run tests"
+task default: :test

erblint-github.gemspec

@@ -1,17 +1,29 @@
 # frozen_string_literal: true
 
 Gem::Specification.new do |s|
-    s.name = "erblint-github"
-    s.version = "0.0.1"
-    s.summary = "erblint GitHub"
-    s.description = "Code style checking for GitHub Ruby repositories"
-    s.homepage = "https://github.com/github/erblint-github"
-    s.license = "MIT"
-  
-    s.files = Dir["README.md", "LICENSE"]
-  
-    s.required_ruby_version = ">= 2.5.0"
-  
-    s.email = ["opensource+erblint-github@github.com"]
-    s.authors = ["GitHub Open Source"]
-  end
+  s.name = "erblint-github"
+  s.version = "0.0.1"
+  s.summary = "erblint GitHub"
+  s.description = "Code style checking for GitHub Ruby repositories"
+  s.homepage = "https://github.com/github/erblint-github"
+  s.license = "MIT"
+
+  s.files = Dir["README.md", "LICENSE", "lib/**/*"]
+  s.require_paths = ["lib"]
+
+  s.required_ruby_version = ">= 2.5.0"
+
+  s.email = ["opensource+erblint-github@github.com"]
+  s.authors = ["GitHub Open Source"]
+
+  s.add_runtime_dependency     "actionview", ">= 5.0.0"
+  s.add_runtime_dependency     "activesupport", ">= 5.0.0"
+
+  s.add_development_dependency "erb_lint"
+  s.add_development_dependency "minitest", "~> 5.14"
+  s.add_development_dependency "mocha"
+  s.add_development_dependency "rake", "~> 12.0"
+
+  s.add_development_dependency "rubocop", "= 1.13.0"
+  s.add_development_dependency "rubocop-github", "~> 0.16.0"
+end

lib/erb-lint/linters/custom_helpers.rb

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+# frozen_string_literal: true
+
+require "json"
+require "openssl"
+
+module ERBLint
+  module Linters
+    module CustomHelpers
+      def rule_disabled?(processed_source)
+        processed_source.parser.ast.descendants(:erb).each do |node|
+          indicator_node, _, code_node, = *node
+          indicator = indicator_node&.loc&.source
+          comment = code_node&.loc&.source&.strip
+          rule_name = self.class.name.match(/:?:?(\w+)\Z/)[1]
+
+          if indicator == "#" && comment.start_with?("erblint:disable") && comment.match(rule_name)
+            if @offenses.any?
+              clear_offenses
+            else
+              add_offense(processed_source.to_source_range(code_node.loc),
+                          "Unused erblint:disable comment for #{rule_name}")
+            end
+          end
+        end
+      end
+
+      def generate_offense(klass, processed_source, tag, message = nil, replacement = nil)
+        message ||= klass::MESSAGE
+        klass_name = klass.name.demodulize
+        offense = ["#{klass_name}:#{message}", tag.node.loc.source].join("\n")
+        add_offense(processed_source.to_source_range(tag.loc), offense, replacement)
+      end
+
+      def possible_attribute_values(tag, attr_name)
+        value = tag.attributes[attr_name]&.value || nil
+        basic_conditional_code_check(value || "") || [value].compact
+      end
+
+      # Map possible values from condition
+      def basic_conditional_code_check(code)
+        conditional_match = code.match(/["'](.+)["']\sif|unless\s.+/) || code.match(/.+\s?\s["'](.+)["']\s:\s["'](.+)["']/)
+        [conditional_match[1], conditional_match[2]].compact if conditional_match
+      end
+
+      def tags(processed_source)
+        processed_source.parser.nodes_with_type(:tag).map { |tag_node| BetterHtml::Tree::Tag.from_node(tag_node) }
+      end
+    end
+  end
+end

lib/erb-lint/linters/github/accessibility/no_redundant_image_alt.rb

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+# frozen_string_literal: true
+
+require_relative "../../custom_helpers"
+
+module ERBLint
+  module Linters
+    module GitHub
+      module Accessibility
+        class NoRedundantImageAlt < Linter
+          include ERBLint::Linters::CustomHelpers
+          include LinterRegistry
+
+          MESSAGE = "<img> alt prop should not contain `image` or `picture` as screen readers already announce the element as an image"
+          REDUNDANT_ALT_WORDS = %w[image picture].freeze
+
+          def run(processed_source)
+            tags(processed_source).each do |tag|
+              next if tag.name != "img"
+              next if tag.closing?
+
+              alt = possible_attribute_values(tag, "alt").join
+              next if alt.empty?
+
+              generate_offense(self.class, processed_source, tag) if (alt.downcase.split & REDUNDANT_ALT_WORDS).any?
+            end
+
+            rule_disabled?(processed_source)
+          end
+        end
+      end
+    end
+  end
+end

test/linter_test_case.rb

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+# frozen_string_literal: true
+
+class LinterTestCase < Minitest::Test
+  def setup
+    @linter = linter_class&.new(file_loader, linter_class.config_schema.new)
+  end
+
+  def linter_class
+    raise NotImplementedError
+  end
+
+  def offenses
+    @linter.offenses
+  end
+
+  def file_loader
+    ERBLint::FileLoader.new(".")
+  end
+
+  def processed_source
+    ERBLint::ProcessedSource.new("file.rb", @file)
+  end
+
+  def tags
+    processed_source.parser.nodes_with_type(:tag).map { |tag_node| BetterHtml::Tree::Tag.from_node(tag_node) }
+  end
+end

test/linters/accessibility/no_redundant_image_alt_test.rb

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+# frozen_string_literal: true
+
+require "test_helper"
+require "erb-lint/linters/github/accessibility/no_redundant_image_alt"
+
+class NoRedundantImageAltTest < LinterTestCase
+  def linter_class
+    ERBLint::Linters::GitHub::Accessibility::NoRedundantImageAlt
+  end
+
+  def test_warns_if_alt_contains_image
+    @file = "<img alt='image of an octopus'></img>"
+    @linter.run(processed_source)
+
+    refute_empty @linter.offenses
+  end
+
+  def test_warns_if_alt_contains_picture
+    @file = "<img alt='picture of an octopus'></img>"
+    @linter.run(processed_source)
+
+    refute_empty @linter.offenses
+  end
+
+  def test_does_not_warn_if_alt_contains_no_redundant_text
+    @file = "<img alt='an octopus'></img>"
+    @linter.run(processed_source)
+
+    assert_empty @linter.offenses
+  end
+end

test/test_helper.rb

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+# frozen_string_literal: true
+
+ENV["RAILS_ENV"] = "test"
+
+require "erb_lint/all"
+require "minitest"
+require "minitest/autorun"
+require "mocha/minitest"
+require "linter_test_case"