vector-im/element-x-ios/issues/13 - Towncrier setup for PR builds

fastlane/Fastfile

@@ -1,4 +1,5 @@
 require 'yaml'
+require_relative 'changelog'
 
 lane :alpha do
 
@@ -24,7 +25,9 @@ lane :alpha do
     adhoc: true 
   )
 
-  update_app_icon()
+  version = ENV["GITHUB_PR_NUMBER"]
+
+  update_app_icon(caption_text: "PR #{version}")
 
   build_ios_app(
     clean: true,
@@ -39,18 +42,10 @@ lane :alpha do
 
   upload_to_diawi()
 
+  export_version_changes(version: version)
+
 end
 
-private_lane :config_xcodegen_alpha do
-  target_file_path = "../ElementX/SupportingFiles/target.yml"
-  data = YAML.load_file target_file_path
-  data["targets"]["ElementX"]["settings"]["base"]["PRODUCT_NAME"] = "ElementX PR"
-  data["targets"]["ElementX"]["settings"]["base"]["PRODUCT_BUNDLE_IDENTIFIER"] = "io.element.elementx.pr"
-  File.open(target_file_path, 'w') { |f| YAML.dump(data, f) }
-end
-
-
-
 lane :build_and_publish_on_github do
   ios_adhoc()
 
@@ -102,6 +97,26 @@ lane :tests do
 
 end
 
+private_lane :export_version_changes do |options|
+  Dir.chdir("..") do
+    Changelog.update_topmost_section(version: options[:version], additional_entries: {})
+    changelog = Changelog.extract_first_section
+
+    # Pushing them directly into the $GITHUB_ENV results in errors
+    # https://trstringer.com/github-actions-multiline-strings/
+    # String substitution and here documents failed too
+    sh("echo '#{changelog}' >> version_changes.md")
+  end
+end
+
+private_lane :config_xcodegen_alpha do
+  target_file_path = "../ElementX/SupportingFiles/target.yml"
+  data = YAML.load_file target_file_path
+  data["targets"]["ElementX"]["settings"]["base"]["PRODUCT_NAME"] = "ElementX PR"
+  data["targets"]["ElementX"]["settings"]["base"]["PRODUCT_BUNDLE_IDENTIFIER"] = "io.element.elementx.pr"
+  File.open(target_file_path, 'w') { |f| YAML.dump(data, f) }
+end
+
 desc "Upload IPA to Diawi"
 private_lane :upload_to_diawi do
   api_token = ENV["DIAWI_API_TOKEN"]
@@ -153,10 +168,9 @@ private_lane :release_to_github do
   )
 end
 
-private_lane :update_app_icon do
-  pr_number = ENV["GITHUB_PR_NUMBER"]
-  UI.user_error!("Invalid GitHub PR number.") unless !pr_number.to_s.empty?
-  caption_text="PR ##{pr_number}"
+private_lane :update_app_icon do |options|
+  caption_text = options[:caption_text]
+  UI.user_error!("Invalid caption text.") unless !caption_text.to_s.empty?
 
   Dir.glob("../ElementX/Resources/Assets.xcassets/AppIcon.appiconset/**/*.png") do |file_name|
     # Change the icons color

fastlane/README.md

@@ -53,6 +53,14 @@ For _fastlane_ installation instructions, see [Installing _fastlane_](https://do
 
 
 
+### export_release_notes
+
+```sh
+[bundle exec] fastlane export_release_notes
+```
+
+
+
 ----
 
 This README.md is auto-generated and will be re-generated every time [_fastlane_](https://fastlane.tools) is run.

fastlane/changelog.rb

@@ -0,0 +1,63 @@
+# Copyright 2020 New Vector Ltd - All Rights Reserved
+# Unauthorized copying of this file, via any medium is strictly prohibited
+# Proprietary and confidential
+
+# frozen_string_literal: true
+
+require "tempfile"
+require "fileutils"
+require "date"
+
+# Helper methods to handle updates of the Changelog file
+#
+module Changelog
+  CHANGES_SEPARATOR_REGEX = /^\#\#\ Changes/.freeze
+  FILE = "CHANGES.md"
+
+  # Update the topmost section of the changelog to put version+date in title + add entry for dependency updates
+  #
+  # @param [String] version The version that we are releasing to use in the new title of the first section
+  # @param [Hash<String, Array<String>>] additional_entries
+  #        List of lines/entries to add under the each subsection of the first section
+  #        The keys of the hash are the name of the subsections, without trailing`:`, e.g. "Improvements".
+  #        The values are the list of lines to add to that subsection
+  #        (the ` * ` bullet point will be added automatically for each line)
+  #
+  def self.update_topmost_section(version:, additional_entries:)
+
+    # Create temporary towncrier changelog entries for additional entries
+    # Use a low index to make them appear first
+    # Those additional entries are basically dependency updates
+    entry_count = 0
+    additional_entries.each do |subsection, entries|
+      entries.each do |entry|
+        file = "changelog.d/x-nolink-#{entry_count}.#{subsection}"
+        File.write(file, "#{entry}")
+        Git.add!(files: file)
+        Git.commit!(message: "changelog.d: #{entry}", add_all: true)
+        entry_count += 1
+      end
+    end
+
+    # Let towncrier update the change
+    system("towncrier", "build", "--version", "#{version}", "--yes")
+  end
+
+  # Returns the first section of the Changelog, corresponding to the changes in the latest version
+  #
+  def self.extract_first_section
+    lines = []
+    File.open(FILE, "r") do |file|
+      section_index = 0
+      file.each_line do |line|
+        is_separator_line = (line.chomp =~ CHANGES_SEPARATOR_REGEX)
+        section_index += 1 if is_separator_line
+        break if section_index >= 2
+
+        lines.append(line) if section_index == 1
+      end
+    end
+    lines[0..-2].join # Remove last line (title of section 2)
+  end
+
+end