Added dry_run flag

CHANGES.md

@@ -2,8 +2,10 @@
 
 ## Version v0.1.8
 
-* `always_run` for tasks that run even if their dependencies
+* Added `always_run` flag for tasks that run even if their dependencies
   are unchanged.
+* Added `dry_run` flag for run_tasks, which will not actually run the
+  procs.
 
 ## Version v0.1.7
 

TODO.md

@@ -7,6 +7,7 @@
 * Once it works fine with files, generalize to a k/v store using [kiwi](ihttps://github.com/crystal-community/kiwi)
 * Make Task/TaskManager structs
 
+* ~~Implement dry runs~~
 * ~~Tasks that *always* run~~
 * ~~Provide a way to ask to run tasks without outputs (needed for hacé)~~
 * ~~Refactor the Task registry into its own class separate from Task itself~~

shard.yml

@@ -1,5 +1,5 @@
 name: croupier
-version: 0.1.7
+version: 0.1.8
 description: A smart task definition and execution library
 authors:
   - Roberto Alsina <[email protected]>

spec/croupier_spec.cr

@@ -254,6 +254,17 @@ describe "Croupier::TaskManager" do
     end
   end
 
+  it "should run no tasks when dry_run is true" do
+    with_tasks do
+      Dir.cd "spec/files" do
+        Croupier::TaskManager.run_tasks(run_all: true, dry_run: true)
+        Croupier::TaskManager.tasks.keys.each do |k|
+          File.exists?(k).should be_false
+        end
+      end
+    end
+  end
+
   it "should run all stale tasks when run_all is false" do
     with_tasks do
       Dir.cd "spec/files" do

src/croupier.cr

@@ -6,7 +6,7 @@ require "log"
 require "./topo_sort"
 
 module Croupier
-  VERSION = "0.1.7"
+  VERSION = "0.1.8"
 
   # A Task is an object that may generate output
   #
@@ -369,10 +369,10 @@ module Croupier
     end
 
     # Run the tasks needed to create or update the requested targets
-    def self.run_tasks(targets : Array(String), run_all : Bool = false)
+    def self.run_tasks(targets : Array(String), run_all : Bool = false, dry_run : Bool = false)
       mark_stale_inputs
       tasks = dependencies(targets)
-      _run_tasks(tasks, run_all)
+      _run_tasks(tasks, run_all, dry_run)
     end
 
     # Check if all inputs are either task outputs or existing files
@@ -387,18 +387,19 @@ module Croupier
     # Run all stale tasks in dependency order
     #
     # If `run_all` is true, run non-stale tasks too
-    def self.run_tasks(run_all : Bool = false)
+    def self.run_tasks(run_all : Bool = false, dry_run : Bool = false)
       mark_stale_inputs
       _, tasks = TaskManager.sorted_task_graph
       check_dependencies
-      _run_tasks(tasks, run_all)
+      _run_tasks(tasks, run_all, dry_run)
     end
 
     # Helper to run tasks
-    def self._run_tasks(outputs, run_all : Bool = false)
+    def self._run_tasks(outputs, run_all : Bool = false, dry_run : Bool = false)
       outputs.each do |output|
         if @@tasks.has_key?(output) && (run_all || @@tasks[output].@stale || @@tasks[output].@always_run)
-          @@tasks[output].run
+          Log.info { "Running task for #{output}" }
+          @@tasks[output].run unless dry_run
         end
       end
       save_run