Configure watch via .amber.yml (#996)

* restart server process if it stops; display compilation time; improved wording of messages

* amber watch: can now (optionally) read config from .amber.yml (see template for details); rewrote ProcessRunner to handle any generic task that can be specified by a set of build and run commands and a set of globs to include and exclude; removed unused build_args and run_args args

* resolved ameba warnings

src/amber/cli/commands/watch.cr

@@ -20,8 +20,6 @@ module Amber::CLI
 
       def run
         CLI.toggle_colors(options.no_color?)
-        options.watch << "./config/**/*.cr"
-        options.watch << "./src/views/**/*.slang"
         super
       end
     end

src/amber/cli/config.cr

@@ -1,28 +1,81 @@
 module Amber::CLI
   def self.config
     if File.exists? AMBER_YML
-      Config.from_yaml File.read(AMBER_YML)
+      begin
+        Config.from_yaml File.read(AMBER_YML)
+      rescue ex : YAML::ParseException
+        logger.error "Couldn't parse #{AMBER_YML} file", "Watcher", :red
+        exit 1
+      end
     else
       Config.new
     end
   end
 
   class Config
+    SHARD_YML    = "shard.yml"
+    DEFAULT_NAME = "[process_name]"
+
+    # see defaults below
+    alias WatchOptions = Hash(String, Hash(String, Array(String)))
+
     property database : String = "pg"
     property language : String = "slang"
     property model : String = "granite"
     property recipe : (String | Nil) = nil
     property recipe_source : (String | Nil) = nil
+    property watch : WatchOptions
 
     def initialize
+      @watch = default_watch_options
     end
 
     YAML.mapping(
       database: {type: String, default: "pg"},
       language: {type: String, default: "slang"},
       model: {type: String, default: "granite"},
       recipe: String | Nil,
-      recipe_source: String | Nil
+      recipe_source: String | Nil,
+      watch: {type: WatchOptions, default: default_watch_options}
     )
+
+    def default_watch_options
+      appname = self.class.get_name
+
+      WatchOptions{
+        "run" => Hash{
+          "build_commands" => [
+            "mkdir -p bin",
+            "crystal build ./src/#{appname}.cr -o bin/#{appname}",
+          ],
+          "run_commands" => [
+            "bin/#{appname}",
+          ],
+          "include" => [
+            "./config/**/*.cr",
+            "./src/**/*.cr",
+            "./src/views/**/*.slang",
+          ],
+        },
+        "npm" => Hash{
+          "build_commands" => [
+            "npm install --loglevel=error",
+          ],
+          "run_commands" => [
+            "npm run watch",
+          ],
+        },
+      }
+    end
+
+    def self.get_name
+      if File.exists?(SHARD_YML) &&
+         (yaml = YAML.parse(File.read SHARD_YML)) &&
+         (name = yaml["name"]?)
+        name.as_s
+      else
+        DEFAULT_NAME
+      end
+    end
   end
 end

src/amber/cli/helpers/helpers.cr

@@ -39,5 +39,8 @@ module Amber::CLI::Helpers
     else
       Process.new(command, shell: shell, output: Process::Redirect::Inherit, error: Process::Redirect::Inherit)
     end
+  rescue ex : Errno
+    # typically means we could not find the executable
+    ex
   end
 end

src/amber/cli/helpers/process_runner.cr

@@ -2,113 +2,192 @@ require "./helpers"
 
 module Sentry
   class ProcessRunner
-    property processes = [] of Process
+    property processes = Hash(String, Array(Process)).new
     property process_name : String
-    property files = [] of String
     @logger : Amber::Environment::Logger
-    FILE_TIMESTAMPS = {} of String => String
+    FILE_TIMESTAMPS = Hash(String, Int64).new
 
     def initialize(
       @process_name : String,
-      @build_command : String,
-      @run_command : String,
-      @build_args : Array(String) = [] of String,
-      @run_args : Array(String) = [] of String,
-      files = [] of String,
+      @build_commands = Hash(String, String).new,  # { "task1" => [ ... ], "task2" => [ ... ] }
+      @run_commands = Hash(String, String).new,    # { "task1" => [ ... ], "task2" => [ ... ] }
+      @includes = Hash(String, Array(String)).new, # { "task1" => [ ... ], "task2" => [ ... ] }
+      @excludes = Hash(String, Array(String)).new, # { "task1" => [ ... ], "task2" => [ ... ] }
       @logger = Amber::CLI.logger
     )
-      @files = files
-      @npm_process = false
       @app_running = false
     end
 
     def run
+      scan_files(no_actions: true)
+      start_processes
+
       loop do
         scan_files
+        check_processes
         sleep 1
       end
     end
 
-    # Compiles and starts the application
-    def start_app
-      build_result = build_app_process
-      if build_result.is_a? Process::Status
-        if build_result.success?
-          stop_all_processes
-          create_all_processes
-          @app_running = true
-        elsif !@app_running
-          log "Compile time errors detected. Shutting down..."
-          exit 1
+    private def scan_files(no_actions = false)
+      # build a list of all files, with their associated tasks
+      all_files = Hash(String, Array(String)).new # { "file" => [ "task1", "task2" ]}
+      changed_files = Array(String).new
+
+      @includes.each do |task, includes|
+        excluded_files = Array(String).new
+        if (excludes = @excludes[task]?)
+          excludes.each { |glob| excluded_files += Dir.glob(glob) }
+        end
+        includes.each do |glob|
+          Dir.glob(glob).each do |f|
+            next if excluded_files.includes?(f)
+            all_files[f] ||= Array(String).new
+            all_files[f] << task
+          end
         end
       end
-    end
 
-    private def scan_files
-      file_counter = 0
-      Dir.glob(files) do |file|
+      all_files.each do |file, tasks|
         timestamp = get_timestamp(file)
         if FILE_TIMESTAMPS[file]? != timestamp
-          if @app_running
-            log "File changed: #{file.colorize(:light_gray)}"
-          end
           FILE_TIMESTAMPS[file] = timestamp
-          file_counter += 1
+          unless no_actions
+            log :scan, "File changed: #{file.colorize(:light_gray)} (will notify: #{tasks.join(", ")})"
+            changed_files << file
+          end
         end
       end
-      if file_counter > 0
-        log "Watching #{file_counter} files (server reload)..."
-        start_app
+
+      return if no_actions || changed_files.empty?
+
+      tasks_to_run = Hash(String, Int32).new
+      changed_files.each do |file|
+        all_files[file].each do |task|
+          tasks_to_run[task] ||= 0
+          tasks_to_run[task] += 1
+        end
       end
-    end
 
-    private def stop_all_processes
-      log "Terminating app #{project_name}..."
-      @processes.each do |process|
-        process.kill unless process.terminated?
+      tasks_to_run.each do |task, changed_file_count|
+        log task, "#{changed_file_count} file(s) changed."
+        start_processes(task)
       end
-      processes.clear
     end
 
-    private def create_all_processes
-      process = create_watch_process
-      @processes << process if process.is_a? Process
-      unless @npm_process
-        create_npm_process
-        @npm_process = true
+    # restart dead processes (currently limited to run task)
+    private def check_processes
+      @processes.each do |task, procs|
+        # clean up process list and restart if terminated
+        if procs.any?
+          procs.reject!(&.terminated?)
+
+          if procs.empty?
+            # restarting currently limited to run task (server process), otherwise just notify
+            if task == "run"
+              log task, "All processes died. Trying to restart..."
+              start_processes(task, skip_build: true)
+            else
+              log task, "Exited"
+            end
+          end
+        end
       end
     end
 
-    private def build_app_process
-      log "Building project #{project_name}..."
-      Amber::CLI::Helpers.run(@build_command)
-    end
+    private def stop_processes(task_to_stop = :all)
+      @processes.each do |task, procs|
+        next unless task_to_stop == :all || task_to_stop.to_s == task
 
-    private def create_watch_process
-      log "Starting #{project_name}..."
-      Amber::CLI::Helpers.run(@run_command, wait: false, shell: false)
+        if task == "run"
+          log task, "Terminating app #{project_name}..."
+        else
+          log task, "Terminating process..."
+        end
+        procs.each do |process|
+          process.kill unless process.terminated?
+        end
+        procs.clear
+      end
     end
 
-    private def create_npm_process
-      node_log "Installing dependencies..."
-      Amber::CLI::Helpers.run("npm install --loglevel=error && npm run watch", wait: false)
-      node_log "Watching public directory"
+    private def start_processes(task_to_start = :all, skip_build = false)
+      if task_to_start == :all || task_to_start == "run"
+        # handle run task first, exit immediately if it fails
+        if (build_command_run = @build_commands["run"]) && (run_command_run = @run_commands["run"])
+          ok_to_run = false
+          if skip_build
+            ok_to_run = true
+          else
+            log :run, "Building..."
+            time = Time.monotonic
+            build_result = Amber::CLI::Helpers.run(build_command_run)
+            exit 1 unless build_result.is_a? Process::Status
+            if build_result.success?
+              log :run, "Compiled in #{(Time.monotonic - time)}"
+              stop_processes("run") if @app_running
+              ok_to_run = true
+            elsif !@app_running # first run
+              log :run, "Compile time errors detected, exiting...", :red
+              exit 1
+            end
+          end
+
+          if ok_to_run
+            process = Amber::CLI::Helpers.run(run_command_run, wait: false, shell: false)
+            if process.is_a? Process
+              @processes["run"] ||= Array(Process).new
+              @processes["run"] << process
+            elsif process.is_a? Exception
+              log :run, "Could not run (#{process.message}), exiting...", :red
+              log :run, "Please check your watch config and try again.", :red
+              exit 1
+            end
+
+            @app_running = true
+          end
+        else
+          log :run, "Build or run commands missing for run task, exiting...", :red
+          exit 1
+        end
+      end
+
+      @run_commands.each do |task, run_command|
+        next if task == "run" # already handled
+        next unless task_to_start == :all || task_to_start.to_s == task
+
+        if (build_command = @build_commands[task]?) && !skip_build
+          log task, "Building..."
+          build_result = Amber::CLI::Helpers.run(build_command)
+          next unless build_result.is_a? Process::Status
+
+          if build_result.success?
+            Amber::CLI::Helpers.run(build_command)
+          else
+            log task, "Build step failed."
+            next # don't continue to run command step
+          end
+        end
+
+        log task, "Starting..."
+        process = Amber::CLI::Helpers.run(run_command, wait: false, shell: true)
+        if process.is_a? Process
+          @processes[task] ||= Array(Process).new
+          @processes[task] << process
+        end
+      end
     end
 
     private def get_timestamp(file : String)
-      File.info(file).modification_time.to_s("%Y%m%d%H%M%S")
+      File.info(file).modification_time.to_unix
     end
 
     private def project_name
       process_name.capitalize.colorize(:white)
     end
 
-    private def log(msg)
-      @logger.info msg, "Watcher", :light_gray
-    end
-
-    private def node_log(msg)
-      @logger.info msg, "NodeJS", :dark_gray
+    private def log(task, msg, color = :light_gray)
+      @logger.info msg, "Watch #{task}", color
     end
   end
 end