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Improve ERB dependency detection.

The current implementation can't handle some special cases of oddly-formatted Ruby. Now we are able to detect them:

* Multi-line arguments on the `render` call
* Strings containing quotes, e.g. `"something's wrong"`
* Multiple kinds of identifiers - instance variables, class variables and globals
* Method chains as arguments for the `render` call

Also, this fix reduces the rate of "false positives" which showed up when we had calls/access to identifiers containing `render`, like `surrender` and `rendering`.
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1 parent da65fe9 commit c2afa055614f15edfbd2f4c97f9254425286fc6e @britto britto committed Dec 16, 2013
Showing with 145 additions and 21 deletions.
  1. +57 −17 actionview/lib/action_view/dependency_tracker.rb
  2. +88 −4 actionview/test/template/dependency_tracker_test.rb
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74 actionview/lib/action_view/dependency_tracker.rb
@@ -1,7 +1,7 @@
require 'thread_safe'
module ActionView
- class DependencyTracker
+ class DependencyTracker # :nodoc:
@trackers = ThreadSafe::Cache.new
def self.find_dependencies(name, template)
@@ -23,9 +23,36 @@ def self.remove_tracker(handler)
@trackers.delete(handler)
end
- class ERBTracker
+ class ERBTracker # :nodoc:
EXPLICIT_DEPENDENCY = /# Template Dependency: (\S+)/
+ # A valid ruby identifier - suitable for class, method and specially variable names
+ IDENTIFIER = /
+ [[:alpha:]_] # at least one uppercase letter, lowercase letter or underscore
+ [[:word:]]* # followed by optional letters, numbers or underscores
+ /x
+
+ # Any kind of variable name. e.g. @instance, @@class, $global or local.
+ # Possibly following a method call chain
+ VARIABLE_OR_METHOD_CHAIN = /
+ (?:\$|@{1,2})? # optional global, instance or class variable indicator
+ (?:#{IDENTIFIER}\.)* # followed by an optional chain of zero-argument method calls
+ (?<dynamic>#{IDENTIFIER}) # and a final valid identifier, captured as DYNAMIC
+ /x
+
+ # A simple string literal. e.g. "School's out!"
+ STRING = /
+ (?<quote>['"]) # an opening quote
+ (?<static>.*?) # with anything inside, captured as STATIC
+ \k<quote> # and a matching closing quote
+ /x
+
+ # Part of any hash containing the :partial key
+ PARTIAL_HASH_KEY = /
+ (?:\bpartial:|:partial\s*=>) # partial key in either old or new style hash syntax
+ \s* # followed by optional spaces
+ /x
+
# Matches:
# render partial: "comments/comment", collection: commentable.comments
# render "comments/comments"
@@ -36,11 +63,13 @@ class ERBTracker
# render(topics) => render("topics/topic")
# render(message.topics) => render("topics/topic")
RENDER_DEPENDENCY = /
- render\s* # render, followed by optional whitespace
- \(? # start an optional parenthesis for the render call
- (partial:|:partial\s+=>)?\s* # naming the partial, used with collection -- 1st capture
- ([@a-z"'][@\w\/\."']+) # the template name itself -- 2nd capture
- /x
+ \brender\b # render, the whole word
+ \s*\(?\s* # optional opening paren surrounded by spaces
+ (?:
+ (?:.*?#{PARTIAL_HASH_KEY})? # optional hash, up to the partial key declaration
+ (?:#{STRING}|#{VARIABLE_OR_METHOD_CHAIN}) # finally, the dependency name of interest
+ )
+ /xm
def self.call(name, template)
new(name, template).dependencies
@@ -68,19 +97,30 @@ def directory
end
def render_dependencies
- source.scan(RENDER_DEPENDENCY).
- collect(&:second).uniq.
+ render_dependencies = []
- # render(@topic) => render("topics/topic")
- # render(topics) => render("topics/topic")
- # render(message.topics) => render("topics/topic")
- collect { |name| name.sub(/\A@?([a-z_]+\.)*([a-z_]+)\z/) { "#{$2.pluralize}/#{$2.singularize}" } }.
+ source.scan(RENDER_DEPENDENCY) do
+ add_dynamic_dependency(render_dependencies, Regexp.last_match[:dynamic])
+ add_static_dependency(render_dependencies, Regexp.last_match[:static])
+ end
- # render("headline") => render("message/headline")
- collect { |name| name.include?("/") ? name : "#{directory}/#{name}" }.
+ render_dependencies.uniq
+ end
+
+ def add_dynamic_dependency(dependencies, dependency)
+ if dependency
+ dependencies << "#{dependency.pluralize}/#{dependency.singularize}"
+ end
+ end
- # replace quotes from string renders
- collect { |name| name.gsub(/["']/, "") }
+ def add_static_dependency(dependencies, dependency)
+ if dependency
+ if dependency.include?('/')
+ dependencies << dependency
+ else
+ dependencies << "#{directory}/#{dependency}"
+ end
+ end
end
def explicit_dependencies
View
92 actionview/test/template/dependency_tracker_test.rb
@@ -1,3 +1,5 @@
+# encoding: utf-8
+
require 'abstract_unit'
require 'action_view/dependency_tracker'
@@ -52,23 +54,105 @@ def make_tracker(name, template)
def test_dependency_of_erb_template_with_number_in_filename
template = FakeTemplate.new("<%# render 'messages/message123' %>", :erb)
- tracker = make_tracker('messages/_message123', template)
+ tracker = make_tracker("messages/_message123", template)
assert_equal ["messages/message123"], tracker.dependencies
end
def test_finds_dependency_in_correct_directory
template = FakeTemplate.new("<%# render(message.topic) %>", :erb)
- tracker = make_tracker('messages/_message', template)
+ tracker = make_tracker("messages/_message", template)
assert_equal ["topics/topic"], tracker.dependencies
end
def test_finds_dependency_in_correct_directory_with_underscore
template = FakeTemplate.new("<%# render(message_type.messages) %>", :erb)
- tracker = make_tracker('message_types/_message_type', template)
+ tracker = make_tracker("message_types/_message_type", template)
assert_equal ["messages/message"], tracker.dependencies
end
-end
+ def test_dependency_of_erb_template_with_no_spaces_after_render
+ template = FakeTemplate.new("<%# render'messages/message' %>", :erb)
+ tracker = make_tracker("messages/_message", template)
+
+ assert_equal ["messages/message"], tracker.dependencies
+ end
+
+ def test_finds_no_dependency_when_render_begins_the_name_of_an_identifier
+ template = FakeTemplate.new("<%# rendering 'it useless' %>", :erb)
+ tracker = make_tracker("resources/_resource", template)
+
+ assert_equal [], tracker.dependencies
+ end
+
+ def test_finds_no_dependency_when_render_ends_the_name_of_another_method
+ template = FakeTemplate.new("<%# surrender 'to reason' %>", :erb)
+ tracker = make_tracker("resources/_resource", template)
+
+ assert_equal [], tracker.dependencies
+ end
+
+ def test_finds_dependency_on_multiline_render_calls
+ template = FakeTemplate.new("<%#
+ render :object => @all_posts,
+ :partial => 'posts' %>", :erb)
+
+ tracker = make_tracker("some/_little_posts", template)
+
+ assert_equal ["some/posts"], tracker.dependencies
+ end
+
+ def test_finds_multiple_unrelated_odd_dependencies
+ template = FakeTemplate.new("
+ <%# render('shared/header', title: 'Title') %>
+ <h2>Section title</h2>
+ <%# render@section %>
+ ", :erb)
+
+ tracker = make_tracker("multiple/_dependencies", template)
+
+ assert_equal ["shared/header", "sections/section"], tracker.dependencies
+ end
+
+ def test_finds_dependencies_for_all_kinds_of_identifiers
+ template = FakeTemplate.new("
+ <%# render $globals %>
+ <%# render @instance_variables %>
+ <%# render @@class_variables %>
+ ", :erb)
+
+ tracker = make_tracker("identifiers/_all", template)
+
+ assert_equal [
+ "globals/global",
+ "instance_variables/instance_variable",
+ "class_variables/class_variable"
+ ], tracker.dependencies
+ end
+
+ def test_finds_dependencies_on_method_chains
+ template = FakeTemplate.new("<%# render @parent.child.grandchildren %>", :erb)
+ tracker = make_tracker("method/_chains", template)
+
+ assert_equal ["grandchildren/grandchild"], tracker.dependencies
+ end
+
+ def test_finds_dependencies_with_special_characters
+ template = FakeTemplate.new("<%# render @pokémon, partial: 'ピカチュウ' %>", :erb)
+ tracker = make_tracker("special/_characters", template)
+
+ assert_equal ["special/ピカチュウ"], tracker.dependencies
+ end
+
+ def test_finds_dependencies_with_quotes_within
+ template = FakeTemplate.new("
+ <%# render \"single/quote's\" %>
+ <%# render 'double/quote\"s' %>
+ ", :erb)
+ tracker = make_tracker("quotes/_single_and_double", template)
+
+ assert_equal ["single/quote's", 'double/quote"s'], tracker.dependencies
+ end
+end

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