Narrow statistics cache invalidation

Author: samuel-williams-shopify

lib/covered/markdown_summary.rb

@@ -23,17 +23,17 @@ def initialize(threshold: 1.0)
 		# 	@parameter coverage [Covered::Coverage] The coverage object below the threshold.
 		# @returns [Covered::Statistics] Statistics for all coverage objects, including omitted ones.
 		def each(wrapper)
-			coverages = []
+			statistics = Statistics.new
 
 			wrapper.each do |coverage|
-				coverages << coverage
+				statistics << coverage
 
 				if @threshold.nil? or coverage.ratio < @threshold
 					yield coverage
 				end
 			end
 
-			return Statistics.new(Statistics::Aggregate.new(coverages))
+			return statistics
 		end
 
 		# Print any annotations for the given line.

lib/covered/statistics.rb

@@ -19,7 +19,9 @@ class Statistics
 		# @parameter coverage [Covered::Coverage] The coverage object to summarize.
 		# @returns [Covered::Statistics] Statistics containing the given coverage.
 		def self.for(coverage)
-			self.new(Aggregate.new([coverage]))
+			self.new.tap do |statistics|
+				statistics << coverage
+			end
 		end
 
 		# Immutable aggregate coverage statistics.
@@ -42,7 +44,6 @@ def initialize(coverages = [])
 				end
 
 				paths.each_value(&:freeze)
-				@paths = paths.freeze
 
 				@count = paths.size
 				@executable_count = paths.sum{|_path, coverage| coverage.executable_count}
@@ -63,23 +64,6 @@ def initialize(coverages = [])
 			# @returns [Integer] The executed line count.
 			attr :executed_count
 
-			# @attribute [Hash(String, Covered::Coverage)] Coverage statistics indexed by path.
-			attr :paths
-			
-			# Add coverage to a new aggregate statistics object.
-			# @parameter coverage [Covered::Coverage] The coverage object to add.
-			# @returns [Covered::Statistics::Aggregate] The new aggregate statistics.
-			def with(coverage)
-				self.class.new(@paths.values + [coverage])
-			end
-			
-			# Get coverage for the given path.
-			# @parameter path [String] The source path.
-			# @returns [Covered::Coverage | Nil] The merged coverage for the path.
-			def [](path)
-				@paths[path]
-			end
-			
 			# A JSON-compatible representation of these aggregate statistics.
 			# @returns [Hash] The aggregate count, line counts and percentage.
 			def as_json
@@ -99,31 +83,25 @@ def to_json(options)
 			end
 		end
 
-		# Initialize coverage statistics.
-		# @parameter aggregate [Covered::Statistics::Aggregate] The aggregate coverage statistics.
-		def initialize(aggregate = Aggregate.new)
-			@aggregate = aggregate
+		# Initialize empty coverage statistics.
+		def initialize
+			@total = nil
+			@paths = Hash.new
 		end
 
-		# @attribute [Covered::Statistics::Aggregate] The aggregate coverage statistics.
-		attr :aggregate
-		
 		# The total aggregate statistics.
 		# @returns [Covered::Statistics::Aggregate] The total aggregate statistics.
 		def total
-			@aggregate
+			@total ||= Aggregate.new(@paths.values)
 		end
 
-		# Coverage statistics indexed by path.
-		# @returns [Hash(String, Covered::Coverage)] The coverage statistics indexed by path.
-		def paths
-			@aggregate.paths
-		end
+		# @attribute [Hash(String, Covered::Coverage)] Coverage statistics indexed by path.
+		attr :paths
 
 		# The number of unique paths with coverage data.
 		# @returns [Integer] The number of unique paths.
 		def count
-			@aggregate.count
+			@paths.size
 		end
 
 		# The total number of executable lines.
@@ -141,7 +119,15 @@ def executed_count
 		# Add coverage to these statistics.
 		# @parameter coverage [Covered::Coverage] The coverage object to add.
 		def << coverage
-			@aggregate = @aggregate.with(coverage)
+			current = @paths[coverage.path]
+			
+			unless current
+				current = @paths[coverage.path] = coverage.empty
+			end
+			
+			current.merge!(coverage)
+			
+			@total = nil
 
 			return self
 		end
@@ -150,7 +136,7 @@ def << coverage
 		# @parameter path [String] The source path.
 		# @returns [Covered::Coverage | Nil] The merged coverage for the path.
 		def [](path)
-			@aggregate[path]
+			@paths[path]
 		end
 
 		# A JSON-compatible representation of these statistics.

lib/covered/summary.rb

@@ -45,17 +45,17 @@ def terminal(output)
 		# 	@parameter coverage [Covered::Coverage] The coverage object below the threshold.
 		# @returns [Covered::Statistics] Statistics for all coverage objects, including omitted ones.
 		def each(wrapper)
-			coverages = []
+			statistics = Statistics.new
 
 			wrapper.each do |coverage|
-				coverages << coverage
+				statistics << coverage
 
 				if @threshold.nil? or coverage.ratio < @threshold
 					yield coverage
 				end
 			end
 
-			return Statistics.new(Statistics::Aggregate.new(coverages))
+			return statistics
 		end
 
 		# Print any annotations for the given line.

test/covered/statistics.rb

@@ -79,6 +79,24 @@ def before
 			expect(statistics).to be(:complete?)
 		end
 	end
+	
+	with "after reading total before adding coverage" do
+		let(:partial_coverage) {Covered::Coverage.new(source, [nil, 1, 0])}
+		let(:complete_coverage) {Covered::Coverage.new(source, [nil, 0, 1])}
+		
+		def before
+			statistics << partial_coverage
+			statistics.total
+			statistics << complete_coverage
+			super
+		end
+		
+		it "invalidates cached totals" do
+			expect(statistics.count).to be == 1
+			expect(statistics.executable_count).to be == 2
+			expect(statistics.executed_count).to be == 1
+		end
+	end
 end
 
 describe Covered::Statistics::Aggregate do
@@ -96,38 +114,14 @@ def before
 			expect(aggregate.executable_count).to be == 3
 			expect(aggregate.executed_count).to be == 2
 		end
-		
-		it "indexes merged coverage by path" do
-			expect(aggregate["foo.rb"].counts).to be == [nil, 2, 1]
-			expect(aggregate["bar.rb"].counts).to be == [nil, 0]
-		end
 	end
 
 	with "an existing aggregate" do
 		let(:coverage) {Covered::Coverage.new(source, [nil, 1])}
-		let(:other_coverage) {Covered::Coverage.new(other_source, [nil, 0])}
 		let(:aggregate) {subject.new([coverage])}
 
 		it "is immutable" do
 			expect(aggregate).to be(:frozen?)
-			expect(aggregate.paths).to be(:frozen?)
-			expect(aggregate["foo.rb"]).to be(:frozen?)
-			
-			expect do
-				aggregate.paths["bar.rb"] = other_coverage
-			end.to raise_exception(FrozenError)
-		end
-		
-		it "returns a new aggregate when adding coverage" do
-			next_aggregate = aggregate.with(other_coverage)
-			
-			expect(aggregate.count).to be == 1
-			expect(aggregate.executable_count).to be == 1
-			expect(aggregate.executed_count).to be == 1
-			
-			expect(next_aggregate.count).to be == 2
-			expect(next_aggregate.executable_count).to be == 2
-			expect(next_aggregate.executed_count).to be == 1
 		end
 	end
 end