update coverage rake task

.circleci/config.yml

@@ -42,4 +42,4 @@ jobs:
       - run:
           name: Check Coveralls coverage on staging
           command: |
-            sudo docker-compose run -e CIRCLE_SHA1="$CIRCLE_SHA1" web rake coverage:run
+            sudo docker-compose run -e CIRCLE_SHA1="$CIRCLE_SHA1" CIRCLE_BRANCH="$CIRCLE_BRANCH" web rake coverage:run

lib/tasks/coverage.rake

@@ -1,14 +1,34 @@
 COVERAGE_FILE_PATH = "./coverage_fe/index.html"
 THRESHOLD      = 0.001
-REPO_URL       = "https://api.github.com/repos/Farmbot/Farmbot-Web-App/git"\
-                 "/refs/heads/staging"
+REPO_URL       = "https://api.github.com/repos/Farmbot/Farmbot-Web-App"
+CURRENT_BRANCH = ENV.fetch("CIRCLE_BRANCH", "staging")
 CURRENT_COMMIT = ENV.fetch("CIRCLE_SHA1", "")
 CSS_SELECTOR   = ".fraction"
 FRACTION_DELIM = "/"
 
 # Fetch JSON over HTTP. Rails probably already has a helper for this :shrug:
 def open_json(url)
-  JSON.parse(open(url).read)
+  begin
+    JSON.parse(open(url).read)
+  rescue OpenURI::HTTPError => exception
+    puts exception.message
+    return {}
+  end
+end
+
+# Assemble the coverage data URL using the provided branch.
+def coverage_url(branch)
+  commit = open_json("#{REPO_URL}/git/refs/heads/#{branch}").dig("object", "sha")
+  return "https://coveralls.io/builds/#{commit}.json"
+end
+
+# Fetch relevant remote coverage data.
+def fetch_build_data(url)
+  build_data = open_json(url)
+  return {
+    branch: build_data.dig("branch"),
+    commit: build_data.dig("commit_sha"),
+    percent: build_data.dig("covered_percent")}
 end
 
 def to_percent(pair)
@@ -18,6 +38,7 @@ end
 namespace :coverage do
   desc "Coveralls stats stopped working :("
   task run: :environment do
+    # Fetch current build coverage data from the HTML summary.
     statements, branches, functions, lines = Nokogiri::HTML(open(COVERAGE_FILE_PATH))
       .css(CSS_SELECTOR)
       .map(&:text)
@@ -30,41 +51,62 @@ namespace :coverage do
     puts "Branches:   #{to_percent(branches)}%"
     puts "Functions:  #{to_percent(functions)}%"
     puts "Lines:      #{to_percent(lines)}%"
-    puts
 
+    # Calculate an aggregate coverage percentage for the current build.
     covered       = lines.head + branches.head
     total         = lines.tail + branches.tail
     build_percent = (covered / total) * 100
+    puts "Aggregate:  #{build_percent.round(4)}%"
+    puts
 
-    latest_commit_staging = open_json(REPO_URL).dig("object", "sha")
-    puts "staging: #{latest_commit_staging}"
-    build_url             = "https://coveralls.io/builds/#{latest_commit_staging}.json"
-    any_build_url         = "https://coveralls.io/github/FarmBot/Farmbot-Web-App.json"
-    begin
-      staging_percent     = open_json(build_url).fetch("covered_percent") ||
-      open_json(any_build_url).fetch("covered_percent")
-    rescue OpenURI::HTTPError => exception
-      puts exception.message
+    # Attempt to fetch remote build coverage data for the current branch.
+    remote = fetch_build_data(coverage_url(CURRENT_BRANCH))
+
+    if remote[:percent].nil? && CURRENT_COMMIT == remote[:commit]
+      puts "Coverage already calculated for #{remote[:branch]}."
+      puts "Using this build's data instead."
+      remote[:percent] = build_percent
+    end
+
+    if remote[:percent].nil? && CURRENT_BRANCH != "staging"
+      puts "Error getting coveralls data for #{CURRENT_BRANCH}."
+      puts "Attempting to use staging build coveralls data."
+      remote = fetch_build_data(coverage_url("staging"))
+    end
+
+    if remote[:percent].nil?
+      puts "Error getting coveralls data for staging."
+      puts "Attempting to use latest build coveralls data."
+      latest_cov_url = "https://coveralls.io/github/FarmBot/Farmbot-Web-App.json"
+      remote = fetch_build_data(latest_cov_url)
+    end
+
+    if remote[:percent].nil?
       puts "Error getting coveralls data."
-      puts "Wait for staging build to finish and try again."
-      puts "If error continues, perhaps a blinky test failed the staging build."
-      staging_percent     = 100
+      puts "Wait for build to finish and try again or check for build errors."
+      puts "Using 100 instead of nil for remote coverage value."
+      remote = {branch: "N/A", commit: "", percent: 100}
     end
 
-    if CURRENT_COMMIT == latest_commit_staging
-      staging_percent = build_percent
-    end
+    # Adjust remote build data values for printing.
+    r = {
+      branch: (remote[:branch] + ' ' * 8)[0,8],
+      percent: remote[:percent].round(8),
+      commit: remote[:commit][0,8]}
 
-    diff = (build_percent - staging_percent)
+    # Calculate coverage difference between the current and previous build.
+    diff = (build_percent - remote[:percent])
     pass = (diff > -THRESHOLD)
 
+    puts
     puts "=" * 37
     puts "COVERAGE RESULTS"
-    puts "This build:    #{build_percent.round(8)}% #{CURRENT_COMMIT[0,8]}"
-    puts "Staging build: #{staging_percent.round(8)}% #{latest_commit_staging[0,8]}"
+    puts "This build:     #{build_percent.round(8)}% #{CURRENT_COMMIT[0,8]}"
+    puts "#{r[:branch]} build: #{r[:percent]}% #{r[:commit]}"
     puts "=" * 37
-    puts "Difference:    #{diff.round(8)}%"
-    puts "Pass?:         #{pass ? "yes" : "no"}"
+    puts "Difference:     #{diff.round(8)}%"
+    puts "Pass?           #{pass ? "yes" : "no"}"
+    puts
 
     exit pass ? 0 : 1